bed bug on servosphere - photo: Vincent Harraca

Ever since seeing this photograph of Vincent Harraca’s research at Lund University (Sweden) I have been looking forward to learning more.

This year Dr. Harraca and his colleagues published two deeply interesting articles about the olfactory physiology of the bed bug and the interplay of chemical signals in bed bug mating. Male bed bugs approach recently fed bed bugs of either sex, but they quickly dismount males and large nymphs. This observation, building on recent investigations, led to a valuable mating-disruption experiment.

But I also wanted to ask about the impetus for bed bug research projects—as we learn more about the bed bug, we see more clearly how much is still unknown.

Dr. Harraca generously took the time to answer my questions via email, from South Africa where he is now researching an entomopathogenic fungus against an agricultural pest.

NYvsBB: I am excited by what feels like rushing advancement in our understanding of how bed bugs perceive odors from hosts and from other bed bugs and how they may interpret those cues and signals, to get what they want and where they’re going. It seems that your and other research teams have begun to fill in the physiology and behavior gaps. To an observer it seems like rapid progress. Although of course the gaps also seem large. But just in the past year you’ve described the olfactory system of the bed bug, two previously unreported nymph-specific chemical compounds were identified (Feldlaufer et al. 2010), and you and your colleagues devised a behavioral experiment that neatly exploits all this new knowledge.

But I confess I am impatient for the research that would eventually describe in all its complex detail how bed bugs find and access their hosts for a blood meal. So perhaps that is my first question, do you think signalling between bed bugs is more relevant for control efforts and that has made it a priority for investigation?

Vincent Harraca: As you said, we started to fill in the gaps about bed bug physiology and behaviour. However, as most of the research is done by Universities, the focus is most of the time centred on theoretical questions with the aim to improve our general knowledge. Indeed, even if we keep in mind that our results may have a practical output, the information we gain is generally not directly applicable. Of course, it is because bed bugs started to be a problem recognised by the public opinion that academic researchers managed to get grants in order to develop our knowledge about this re-invading pest. Chemical ecology is one of the academic fields which gives the most “visible” results, because olfaction is the major sense used by most insects to orientate and the understanding of their perception permits to modify their behaviour.

NYvsBB: Before we get to your exciting investigation into the disruption of bed bug mating, can I ask about their antennae, the site of all the olfactory action? What are the sensilla for and how do they work? And how did you achieve electrical measurements on such small sites? Did you identify chemical compounds that seem like good candidates for further investigation of their role in bed bug orientation and host-seeking?

Vincent Harraca: An odour is composed by a specific blend of different molecules and it is the perception of some of these molecules by olfactory receptor neurons which is called olfaction. When the adequate odorant molecules bind the adequate neurons, an electrical signal is created and transmitted to the brain. In the insects, these neurons are housed inside sensilla (evaginations of the cuticle looking like hairs) mostly placed on their antennae.

bed bug antennal sensilla: trichoid sensilla (hairs) (E), smooth peg sensilla (D), and grooved peg sensilla (C) - SEM image: Vincent Harraca

Scientists have developed different electrophysiology techniques in order to measure this electrical signal produced after stimulating the neuron with chosen odours. We applied the technique of single sensillum recording on bed bugs and demonstrated some of the compounds bed bugs are able to smell or not (Harraca et al. 2010a). The main conclusion of our study is that compared to other blood feeding insects such as mosquitoes, bed bugs detect fewer compounds, meaning they might mostly rely on other cues than odours to find us. It is also perhaps for this reason that most of the published laboratory experiments (meaning with positive results!) on bed bugs have focused on the detection of their refuge or their interactions with other bed bugs (Levinson & Bar Ilan 1971, Siljander et al. 2008, Olson et al. 2009, Harraca et al. 2010b, Weeks et al. 2010…). In parallel to that, the few studies which have tried to add odorant molecules to traps in order to enhance their attraction failed (Anderson et al. 2009, Wang et al. 2009), but it was mostly because they used mosquito attractant molecules that we showed bed bugs cannot smell (Harraca et al. 2010a). This latest example demonstrated the value of basic theoretical knowledge before application.

NYvsBB: The very small number of odors that bed bugs actually perceive, or respond to, seems significant. Smaller than triatomines. What are odors derived from, excretions from hosts?

Vincent Harraca: Fragmented studies about blood feeding insects seem to demonstrate that they use a combination of compounds from different origin. Some are more associated to the host (i.e. carbon dioxide from the breath, carboxylic acids and octenol from the skin, phenols evacuated via urine) whereas other molecules (such as terpens or ammonia) are more linked to refuge. It is based on this knowledge that the first traps baited with odours were made (Anderson et al. 2009, Wang et al. 2009). Unfortunately, as the olfactory perception of the bed bug seems to be much narrower than other vectors (Harraca et al. 2010a), they do not smell compounds such as lactic acid or octenol used in these studies and which are quite efficient to attract mosquitoes. Until now, CO2 and heat were the only host cues proven to enhance attraction of bed bugs to traps.

NYvsBB: I am thinking of the servosphere experiments I was so looking forward to learning more about—can you tell us about them?

servosphere - photo: Vincent Harraca

Vincent Harraca: Before applying a new technology it is always good to test it in a laboratory controlled environment. But once more, doing behavioural experiments with bed bugs is not straightforward. Indeed, during experiments with arena they mostly followed the wall and scarcely adventure in open areas. For these reasons, many studies only measured the resting position of the bed bug, which in my opinion has no meaning except when looking for refuge cue. In order to see direct behavioural effect (such as seeking for a host?!), we tried to develop experiments on a servosphere (locomotion compensator) which proved to be quite helpful in studying the behaviour of other walking insects (Otálora-Luna et al. 2004…). Indeed, in this system the animal is totally free of movement and never encounters any boundary. Moreover precise information about his displacement (speed, direction, time of walking…) are recorded.

However, we quickly discovered that bed bugs hate moving air which is needed to release the odour to test. So during our experiments with this system, the bed bug systematically walked downwind without any visible difference linked to stimuli.

bed bug tracks recorded with servosphere - Vincent Harraca

That is why we returned to an arena behavioural experiment, but we tried to make it reflect as much as possible the bed bug natural environment and to measure precise behavioural parameters.

In our latest publication with bed bugs (Harraca et al. 2010b), we demonstrated the effect of two molecules that are exclusively emitted by the nymphs (Feldlaufer et al. 2010, Liedtke et al. submitted). The conclusion of this study is that young bed bugs are able to emit two molecules that identify their status and permit them to avoid the traumatic insemination by males. Indeed, when these molecules are emitted the males do not pierce the abdomen or inject any sperm to their partner.

NYvsBB: Where do you think this line of inquiry can take us?

Vincent Harraca: We do not know what could be the effect of introducing such compounds in a bed bug colony, but two scenarios may be possible: it decreases the reproduction rate (as the males think all the females are too young), or it increases the mortality rate of young bed bugs (because the males lose the ability to recognise them and pierce their abdomen while trying to fertilise them). In both situations, there could not be appearance of resistance (as the molecules used are produced by the bed bugs themselves) and this technique will allow a less rapid recovery of the colony after treatment and so, a quicker elimination. I unfortunately do not think these molecules employed on their own will be sufficient on short term eradication and they will have to be coupled to other techniques such as trapping. However, such odorant compounds may also have a repellent effect on the establishment of new colonies.

References:

Anderson, J F, F J Ferrandino, S McKnight, J Nolen, and J Miller. 2009. A carbon dioxide, heat and chemical lure trap for the bedbug, Cimex lectularius. Medical and Veterinary Entomology 23: 99-105. doi:10.1111/j.1365-2915.2008.00790.x.

Feldlaufer, Mark F., Michael J. Domingue, Kamlesh R. Chauhan, and Jeffrey R. Aldrich. 2010. 4-Oxo-Aldehydes from the Dorsal Abdominal Glands of the Bed Bug (Hemiptera: Cimicidae). Journal of Medical Entomology 47: 140-143. doi:10.1603/ME09210. [download PDF here]

Harraca, Vincent, Rickard Ignell, Christer Löfstedt, and Camilla Ryne. 2010a. Characterization of the Antennal Olfactory System of the Bed Bug (Cimex lectularius). Chemical Senses 35: 195-204. doi:10.1093/chemse/bjp096.  

Harraca, Vincent, Camilla Ryne, and Rickard Ignell. 2010b. Nymphs of the common bed bug (Cimex lectularius) produce anti-aphrodisiac defence against conspecific males. BMC Biology 8: 121. doi:10.1186/1741-7007-8-121. [open access]

Levinson, H. Z., and Anna R. Bar Ilan. 1971. Assembling and alerting scents produced by the bedbug Cimex lectularius L. Experientia 27: 102-103. doi:10.1007/BF02137766. [PDF available]

Olson, J.F., R.D. Moon, and S.A. Kells. 2009. Off-host aggregation behavior and sensory basis of arrestment by Cimex lectularius (Heteroptera: Cimicidae). Journal of Insect Physiology 55: 580-587. doi:10.1016/j.jinsphys.2009.03.001.

Otálora-Luna, Fernando, Jean-Luc Perret, and Patrick Guerin. 2004. Appetence behaviours of the triatomine bug Rhodnius prolixus on a servosphere in response to the host metabolites carbon dioxide and ammonia. Journal of Comparative Physiology A 190: 847-854. doi:10.1007/s00359-004-0540-5.  

Siljander, Eric, Regine Gries, Grigori Khaskin, and Gerhard Gries. 2008. Identification of the airborne aggregation pheromone of the common bed bug, Cimex lectularius. Journal of Chemical Ecology 34: 708-718. doi:10.1007/s10886-008-9446-y.

Wang, Changlu, Timothy Gibb, Gary W. Bennett, and Susan McKnight. 2009. Bed Bug (Heteroptera: Cimicidae) Attraction to Pitfall Traps Baited with Carbon Dioxide, Heat, and Chemical Lure. Journal of Economic Entomology 102: 1580-1585. doi:10.1603/029.102.0423.

Weeks, E.N.I., J.G. Logan, S.A. Gezan, C.M. Woodcock, M.A. Birkett, J.A. Pickett, and M.M. Cameron. 2010. A Bioassay for Studying Behavioural Responses of the Common Bed Bug, Cimex Lectularius (Hemiptera: Cimicidae) to Bed Bug-Derived Volatiles. Bulletin of Entomological Research FirstView: 1-8. doi:10.1017/S0007485309990599.

Note: Some of these articles are also available at the Armed Forces Pest Management Board’s free online library.

I have (in my History of the Misery of Bed Bugs collection) a set of notes, passed along like contraband, of his New York County Lawyers’ Association Jack Newton Lerner Lecture on bed bugs, Bed Bugs, Constructive Eviction, Warranty of Habitability: Comments and Cases — an outline of the wonderful story of early bed bug litigation in the city.

When May Berenbaum’s recent NYT op-ed offered (as evidence for the changing fortunes of the persecuted bed bug?) a memorable phrase from an early 20th century New York decision — “[Bedbugs] can be dealt with by the tenant by processes known to all housewives” — I bethought myself my Smollens lecture notes…

Mr. Smollens indulged my questions.

New York vs Bed Bugs: Why look at early 20th century case law in the first place? Are bed bugs and the law like bed bugs and science, where we’re missing quite a big chunk of development and thought?

Steven W. Smollens: That is a potent observation. Science left the bedbug alone for a long time. With the bedbug gone, and modern insecticides left to cope with less offensive insects, when the bedbug came back, there were initially few treatments considered legal and lethal. While our coping skills were not honed to the bedbug spread, our own modern life helped the bedbug move in to one home and business after another.

When the bedbug problem was novel, we did not pay much attention. We missed out on chances to change certain patterns, to make the risks less, and to stem the spread. We passed up early warning, education, and training for exterminators, public officials, tenants, landlords, shopkeepers, travelers, public transportation operators, used furniture and mattress sellers, flea market vendors, college dormitory authorities and the like. The public’s lack of alertness and government’s slow pace, along with housing maintenance codes ill-suited for the new pestilence, has made for a variety of claims for successful pest eradication; but often failure to control is easily passed on to the tenant, or a neighbor or the building manager or landlord and it is hard to support one method of bedbug elimination over any other.

It comes down to “now we know it.” For nearly eighty years, there was not a new bedbug case decided in New York courts involving landlord and tenant. Today’s New York court case will typically involve the application of our Warranty of Habitability statute. But by the first time a warranty of habitability and bedbug case came into the court’s domain for decision, we had missed the chance to an early end to the bedbug’s spread. Today, we can learn a lot from how bedbugs influenced our older landlord and tenant law. We should be able to see ourselves in the tenants who lived in our city one hundred years ago, and realize that by the time bedbugs made it to court at that time, bedbugs were all around.

Early on city life was treated similarly to living in the country. Judges were bound by the state of the law and judges applied the law as it existed to the new circumstances. At the start the law was applied without taking into account the difference in the setting. The loss of control a tenant had over the home in an apartment living in a city is not found when living in a house in the fields. The law gyrated in examining deprivations in habitability and gradually left behind the common law basis of our landlord and tenant law, that the tenant was the equal of a buyer in a market place and thus “let the buyer beware” slowly exited.

The difficulty faced by our earlier city dwellers when confronted by bedbugs was accepted at first as a problem that could be easily handled. That approach took time to change. The law itself developed to recognize that tenants could face problems in their homes, not anticipated by the tenant and the landlord, and not solvable, that would justify breaking of the lease by the tenant and the nonpayment of a portion of the agreed rent.

Today, we have bedbugs in an environment where our city dweller has little or no practical experience in fixing anything at all, let alone a mature insect infestation. Yet, as a community, we have as ancient an approach as we did long ago, when almost every tenant was assumed to have skills to cope with this problem.

Today while the notion is that the landlord must eradicate the bedbugs, in the absence of science, landlords and exterminators, and city agencies, all place an immense pressure upon the tenant to make the home ready for the techniques used by the pest control experts. Unlike any other condition in one’s home, other than perhaps a fire or a flash flood, bedbugs force the tenant into a virtual move-out while still maintaining the apartment as a home. No other home repair requires the tenant to pack all personal belongings, clothing, papers, books, and remove furniture or carpets, and take down pictures, and launder in hot water and then store all garments, or to dry-clean and store away from the home, and to encapsulate mattresses and box springs, just for a start, before extermination can begin. The old days of do-it-self with ant or roach spray do not apply against the bedbug. We are truly not prepared for the dislocation that a bedbug can present.

The harshest reality for our tenants and landlords today is that there is no guarantee that extermination will do the job. Tenants must put their home on hold while waiting out a bedbug life cycle to learn if the insect and its progeny are gone from the home. And because the bedbug is very good at lying dormant, each tenant pins the hope for insect-free living on the skill of the exterminator, the willingness of the landlord to see the eradication through and the cooperation of neighbors. As we are now all too aware, that will not prevent a hitchhiking bedbug to come back again to your home or to a neighbor’s. Living in an apartment in a near-permanent state of packed-up is disheartening.

Constructive Eviction

I looked upon the case law developed in the NY Courts late in the nineteenth century and early in the twentieth century, as a means to discover how judges grappled with the responsibility of a landlord to the tenant, for habitable housing, in an age where the common law rule was best expressed as “The tenant hires at his peril and a rule similar to caveat emptor applies and throws on the lessee the responsibility of examining as to the existence of defects in the premises and of providing against their ill effects…” (Benjamin Franklin v. Mary Brown, 118 N.Y. 110, 23 N.E. 124, Court of Appeals, 1889).

The early cases evolved from the creation of a new legal doctrine, called “constructive eviction.” The law that an “eviction,” whether total or partial, created a full defense against the landlord suing for remaining unpaid rent expanded to making the “constructive eviction” of the tenant a total defense against a landlord’s post-tenancy rent claim.

Previous, but for a breach of lease by the landlord or an actual or partial eviction from the property, tenants had few merit defenses, such as the rent sued for was in fact paid, and so-called “technical defenses.” Those technical defenses, dealing with the rent demand and the service of process, and notice of commencement of the case were similar to the defenses currently utilized by tenants in modern courts. Eerily, the ancient technical cases, read as though written in the modern era, because the so-called “technical defenses” are as real today as when first applied to the modern standard lawsuit for an eviction, the “summary proceeding.”

The early-era version of the summary proceeding (very similar to the modern form) for litigating an eviction cause for a landlord was invented in the early part of the 19th century as a “swift and expeditious remedy” to recover real property to provide a landlord a new method to evict a tenant, instead of the common law ejectment action.

New York State’s land owners convinced the New York legislature to create this new cause of action, in derogation of common law, to replace the common law ejectment action, because in common law the tenant was entitled to a jury trial and the “peers” often had more in common with the tenant-farmer than the wealthy land baron.

By itself, as a doctrine, “constructive eviction” grew from the body of early cases that recognized that an eviction of the tenant, by the landlord without court process, ended the tenant’s obligation to pay the rent that the tenant agreed to pay when the lease was made.

Courts then grappled with parsing the nature of the “eviction” itself, moving from the obvious outright physical ouster from the property [an “actual eviction”], to evictions that were “partial”, that means from a part of the rented or leased property [an “actual partial eviction” or a “partial eviction”] to actions more sublime, such as the landlord perpetrating a nuisance condition, by either directly causing the condition, or by not correcting the condition when informed.

A key element to the proof of a “constructive eviction” was that the condition that forced the tenant to abandon was not known or discoverable when the lease was made, could not when discovered be corrected by the tenant or by the landlord and, that also rendered the leased property unfit for the use actually contemplated by the lease. [Vermin or noxious smells in or about the house did not constitute eviction so as to justify abandonment of the premises by the tenant (Truesdell v. Booth, 4 Hun 100.) A bad smell in the pantry, and the kitchen being too hot with the stove in it, and bad smells from the front window, along with a stagnant pond of water near the place, bad smell from fish, and vermin in the bedrooms, were all matters that might have given some trouble to eradicate, yet none of them could be held sufficient to relieve the tenant from his liability, or to come within the rule that defines an eviction (Vanderbilt v. Persse, 3 E.D. Smith 428.)]

Courts looking to limit the doctrine of “constructive eviction” pointed to the written agreement made by the tenant and the landlord (the lease). “…The apartment in suit was not under the control of the plaintiff, and no evidence was given of any express covenant in the lease to keep the apartment free from vermin; and, in the absence of such a covenant, the lessee, under the circumstances detailed above and in the absence of fraud, deceit or wrong-doing on the part of the plaintiff, ran the risk of the condition of the property in that regard…” Franklin v. Brown, 118 N.Y. 110; Sherman v. Ludin, 79 A.D. 37.

In the newly discovered potential that an eviction could exist without a full or part physical ouster, the New York legislature sought to identify conditions that could exist and present a defense to a tenant, who quit the leased property, although owing a remainder portion of rent as agreed to in the lease.

“…Pomeroy v. Tyler, 9 N.Y. St. Rep. 514, was also a case very similar in its facts to the present one; and it was held, McAdam, Ch. J., writing the opinion, that the fact that the rooms occupied by the tenant were overrun with vermin, namely, bedbugs, cockroaches, croton-bugs and red ants, making it inconvenient to inhabit the premises and rendering them untenantable, did not constitute a constructive eviction of the tenant…

“…The following remarks of Chief Justice McAdam, in the course of such opinion, are especially applicable to the present case: ‘The legislature has passed a statute relieving tenants from their common law obligations, where the demised premises have been destroyed by fire, tempest or other sudden and unexpected event (Laws 1860, chap. 345; Suydam v. Jackson, 54 N.Y. 450), but the legislative sense of relief to tenants has not as yet reached the case of rats, mice, bugs, roaches or other vermin, and all questions as to them must be decided according to the wisdom of the common law. The inconvenience is one to which all more or less are subject at times; but which, with ordinary skill and attention, may be abated by the tenant.’“ Excerpt from Jacobs v. Morand, 59 Misc. 200, 59 Misc. 200, 110 N.Y.S. 208, 1908, (Supreme Court Of New York, Appellate Term.)

Even then, “constructive eviction” was a defense only if the courts recognized the condition that drove the tenant out of the home, as one so noxious and unsolvable, that the tenant’s swift departure evidenced the severity of the condition and the reasonableness of the departure.

“…Leases would not be worth the paper upon which they are written, if the engagements of parties could be set at naught upon such slight and trivial pretexts. To constitute a constructive eviction, there must be an intentional and injurious interference by the landlord, which deprives a tenant of the beneficial enjoyment of the demised premises, or materially impairs such beneficial enjoyment. An eviction depends upon the materiality of the deprivation. If trifling, and producing no substantial discomfort or serious inconvenience, it will be disregarded, and will not afford cause for the termination of the relation of landlord and tenant…” Excerpt from Seaboard Realty Co. v. Fuller, 33 Misc. 109, 67 N.Y.S. 146; (1900, Supreme Court Of New York, Appellate Term)

When judges first expanded the notion of constructive eviction to rental premises abandoned by the tenant due to uninhabitable conditions, the cases set the way for the eventual notion of a warranty that residential premises would be fit for human use. Many other jurisdictions adopted the warranty of habitability before New York. However, the judicial seeds for the New York warranty were set in the early 20th century bedbug cases.

New York vs Bed Bugs: Tell us about these cases. The 1908 decision is the case that would later be characterized as the “processes known to all housewives” case but it actually does not contain the phrase. That coinage belongs to another judge in 1913 who wasn’t actually deciding a bed bug case at all, if I understand correctly, but in trying to make an important distinction (one that I think prefigures the challenges of modern building-wide bed bug infestations where a single tenant acting alone does not really stand a chance) would open the door for yet another bed bug case…

Steven W. Smollens: The 1908 case is Jacobs v. Morand, and the court there relied upon another court’s decision, made in the case of Pomeroy v. Tyler, 9 N.Y. St. Rep. 514, where the quote goes as follows: “…the case of rats, mice, bugs, roaches or other vermin, and all questions as to them must be decided according to the wisdom of the common law. The inconvenience is one to which all more or less are subject at times; but which, with ordinary skill and attention, may be abated by the tenant…”

In 1913, in Barnard Realty Co. v. Bonwit, that became: “…The rule in Jacobs v. Morand (supra) in regard to bugs and ants within the apartment, which can be dealt with by the tenant by processes known to all housewives, should not be extended to cover offensive and unbearable nuisances outside of the apartment…”

Sometimes, the concept that the courts held to, that is, if a condition were bad but fixable, so that any ordinary person could find a way to deal with it, governed the language in place of the actual text. The “processes known to all housewives” was the sound bite that drove home the notion that courts were not going to protect rent-evading tenants, who after departing the home, were sued for the remainder of the rent, and then backwards, try to construct the “constructive eviction.” Judges knew, that if there were a tried and proven remedy, the abandonment by the tenant could not be defended.

The context for the “housewives” comes from Barnard v. Bonwit, the 1913 case:

“…This is an action to recover rent of an apartment. The defense was constructive eviction. The jury found for the defendant. The verdict having been set aside solely as contrary to law, the facts found are established. Defendant and his wife moved into an apartment on the top floor of a new apartment house on the 15th of September, 1910, and moved out on the 8th of November, 1910. The reason therefor was the disturbance caused by the nightly meetings and performances of rats in the walls and ceilings, coupled with a most offensive odor which increased until the place became untenantable.

There are two Appellate Term decisions, one (Jacobs v. Morand, 59 Misc. Rep. 200), in which the presence of bedbugs, croton bugs, red ants, etc., was held not to be sufficient to establish a constructive eviction; and the other (Madden v. Bullock, 115 N. Y. Supp. 723), which held that the loathsome stench of dead and decayed rats was sufficient.

Very large numbers of people live in tenement houses, apartment houses and apartment hotels in this city. Such tenants have, and can have, control only of the inside of their own limited demised premises. Conditions unknown to the ancient common law are thus created. This requires elasticity in the application of the principles thereof. An intolerable condition which the tenant neither causes nor can remedy seems to me warrants the application of the doctrine of constructive eviction. The rule in Jacobs v. Morand (supra) in regard to bugs and ants within the apartment, which can be dealt with by the tenant by processes known to all housewives, should not be extended to cover offensive and unbearable nuisances outside of the apartment. This tenant could not pull down the walls or the ceilings. He and his family ought not to be compelled to pay rent for an apartment in which they could not live.

This court has held that when the landlord had the entire control of the heating plant a failure to provide sufficient steam heat was enough to constitute constructive eviction. (Berlinger v. Macdonald, 149 App. Div. 5.) Of course that case is different from the one at bar because there it was within the power of the landlord to furnish the heat, and if he did not it was an act of omission upon his part. But here the jury have found the existence of an intolerable condition. The tenant did not cause it and could not remedy it. If any one could it was the landlord. He attempted to and failed. We think the flat dweller was justified in his abandonment of the premises. [Excerpt is from Barnard Realty Co. v. Bonwit, 155 A.D. 182, 184 (N.Y. App. Div. 1913)]

The first modern bed bug case, Streep v Simpson

1913 also brought the first modern bedbug case where the court’s analysis made the bedbug infestation the proper basis for finding a constructive eviction. It is worth noting, how present-day sounding the plight of the tenant was nearly one-hundred years ago:

Defendant, a tenant from year to year, was sued for the last month’s rent of a two-years’ occupancy of a flat in plaintiff’s apartment house which he abandoned just prior to the commencement of the last month in question. He sought to justify this abandonment upon the ground that he was constructively evicted owing to the presence of bedbugs in the house. The size of the apartment house does not appear save that there were two flats on a floor, the one occupied by the defendant being on the fourth floor. The defendant, with his family, had occupied this flat for eighteen months without observing the presence of the bugs. From that time on bedbugs were found in his flat, in the private hall thereof, in the parlor, dining-room, and bath-room, on the walls, in the closets, upon the clothing and in the beds to such an increasing and persistent extent as to cause the greatest discomfort and distress to the dwellers therein…

Shortly after having first observed them the defendant notified the landlord, and it appeared upon investigation that the bugs came from the flat underneath defendant’s. That flat was then occupied, but soon after became vacant, and the landlord employed an “exterminator,” who endeavored to drive the bugs both from the defendant’s flat and the one underneath, but without success; and despite the persistent efforts of this trained “exterminator,” coupled with those of the landlord, as well as the defendant and his wife and painters and decorators, the bedbugs continued to increase, befouling the walls, emitting odors and biting the occupants, and exhibiting in their migrations a tendency to abide in the defendant’s flat, probably because there were persons dwelling there. Such, in brief, is the proof, and so it may be said that the defendant’s flat was infested with bedbugs without his fault; and, as the court below has found a constructive eviction, can it be assumed on appeal that the premises were rendered untenantable and that the landlord must bear the loss of the rent?…

Observing the limitations placed by the Appellate Division upon the case of Jacobs v. Morand, as to bugs within the apartment which can be dealt with by the tenant himself, and applying the language of Mr. Justice Clarke, who wrote for the court in Barnard Realty Co. v. Bonwit, we have reached the conclusion that, under the circumstances shown, it could be found, as a fact, that the defendant was constructively evicted and that his abandonment of his tenancy was justifiable.

The proof here shows such a condition as amounted to an insufferable nuisance, and where its existence in an apartment house is in nowise attributable to the fault of the tenant, but arises and is due to conditions in another part of the same building into which the landlord may go and apply a remedy, if remediable, the tenant must be deemed to have been precluded from a beneficial enjoyment of the premises and his abandonment thereof bars the lessor’s action for the recovery of rent. Considering the landlord’s control over the vacant flat underneath for a period of about two months, and the defendant’s eagerness to afford him every opportunity and aid to rid the latter’s flat of the bugs, their presence cannot be said, as a matter of law, not to be due in some measure to the landlord’s fault, or, at least, to his inability to continue the habitableness of the defendant’s dwelling place. An eviction depends upon the materiality of the deprivation. If trifling, and producing no substantial discomfort or serious inconvenience, it will be disregarded and will not afford cause for the termination of the relation of landlord and tenant.” Seaboard Realty Co. v. Fuller, 33 Misc. Rep. 110.

Here the deprivation was most material. It was by no means trifling, and not only did it produce substantial discomfort and severe inconvenience but it amounted to an intolerable state. Whether or not the deprivation is material is a question of fact, and that having been found below in favor of the defendant the judgment should be affirmed, with costs. [The excerpt is from Streep v. Simpson, 80 Misc. 666, 666-669 (N.Y. Misc. 1913)]

The warranty of habitability

New York vs Bed Bugs: So, from an inconvenience to which all more or less are subject at times and processes known to all housewives, to an intolerable condition that the tenant did not cause and cannot remedy on his own. From caveat emptor to an incipient implied warranty of habitability — would that be an accurate way to put it? (But I thought the warranty of habitability was common law, so why did it take so long for it to be re-claimed?)

Steven W. Smollens: Well in fact, the warranty of habitability did not derive from our common law. Our law before we made statutes to define our law, was made in courts, by judges and lawyers and plain folks, taking their disputes to trial and then on to appeal.

Sometimes, those disputes involving claims for monetary damages were for less than $200 and were not finally determined until the battling opponents had made their way from a trial court to the Appellate Division. Along the way the law of Constructive Eviction was helped along by bedbugs and the dueling over which party, landlord or former tenant, was entitled to the rent.

Codified in Real Property Law § 235-b, as amended, the warranty of habitability had its genesis in the trial courts, where judges faced routinely the problems of urban tenants, whose landlords demanded payment of their rent, while not providing to their tenants the benefits they had “bargained” for in their rental agreement. New York law, slowly evolving from its agrarian roots, had not recognized the relationship between the tenant’s obligation to pay rent, and the landlord’s obligation to provide rental premises fit for human habitation.

Absent a fraud, there was “no law against letting a tumble-down house.” As long as there existed an abundance of rental housing, tenants were able to move away from their problems and take the risks inherent in establishing a constructive eviction.

Common sense concepts, involved in routine everyday life, such as grocery shopping (you would not expect to be required to pay for a full loaf of bread if the grocer were to sell only half a loaf) had no place in the relationship of landlord and tenant. As a lease had been found to be a conveyance of real property, the duty imposed by law upon the landlord was satisfied by the delivery of possession to the tenant.

Only the covenant of continued quiet enjoyment of the premises was impliedly warranted by the “conveyance” to the tenant by the landlord. As long as the tenant had the quiet (undisturbed) right to possession of the premises, the tenant remained duty bound to pay the rent, regardless of the conditions in the premises.

These concepts, existing at common law, of no duty to provide services by the landlord, led to landlords not providing maintenance or essential services, especially in areas tenanted by persons of low-income.

The law did not provide the tenant with the tools necessary to compel the landlord to provide essential services or make necessary repairs. Courts outside New York were the first to determine that a lease for residential property impliedly contained a warranty that the premises were habitable.

A lease was slowly seen as more a purchase of shelter than a transfer of real property, and so an implied fitness for the use intended (U.C.C. Sales) was seen as a more realistic approach to determine the obligations of landlords and tenants.

Our state moved into the modern era in 1975, well past the rest of the United States. At that time, an appeals court, the Appellate Division, Second Department declared: “…we relegate to the limbo of history the orthodox view of caveat lessee and hold that, unless expressly excepted, there is an implied warranty of habitability when a landlord leases premises for residential use…” [Excerpt from Tonetti v. Penati, 48 A.D.2d 25, 367 N.Y.S.2d 804 (A.D. Second Dept., 1975)]. That court cited with approval the similar warranty of habitability decisions made in jurisdictions outside New York, e.g., Washington, D.C., Hawaii, Iowa, New Jersey, California and New Hampshire.

The New York State legislature, quickly grabbed the warranty of habitability from the judges, and went further to provide that the warranty is implied in every lease for residential property and could not be excluded from a lease by a contrary express lease provision.

“Too many people remain unaware how many bedbugs can hide out in an ordinary picture frame”

New York vs Bed Bugs: Care to consider what might come next? What refinements do you think are necessary in order to comprehend the magnitude of the current situation? We see landlords and tenants struggling to get relief from each other and just chaos all around. Is the law adequate to the challenges faced by landlords and tenants with this pest? What do you see in your own practice? Or, put another way, what holes do you see legislators might try to fill?

Steven W. Smollens: Right now, as summer draws to a close, we are seeing more media attention, television and radio advertising, and other expressions to make the bedbug infestation more obvious and open. There are billboards along the road, and bedbug sniffing dogs appearing on morning news programs and newspaper articles to work on getting the message out. I have not seen a public service advertisement, or heard one on radio, and if I have missed any, then there are not enough. In a city where in any campaign season we are inundated with political literature, that form of attention grabbing saturation may help spread information and recognition of the growing potential of the bedbugs invasion.

Pest Control persons are candid that there is no one sure-fire method for success in any given bedbug problem, and many residents are not able to face-down the direction to empty all closets, clean and bag all clothing, pack and seal up everything else, and are likely to fail the test for preparation. When tenants are informed that the bugs can hide inside radios, computers and other electronic devices, can scurry off to hide in cracks and crevices in walls and floors, and hide out in electric outlets, the expectation of failure is very high, that the tenant will not be able to get the apartment ready for the exterminator.

There will be need for new technology. The insects life cycle has to be interrupted. Used furniture and mattresses have to be located to a place without people. The habits of urban scavengers in rescuing other persons’ discarded sofas and chairs has to stop. Too many people remain unaware how many bedbugs can hide out in an ordinary picture frame.

There is a positive role for government at least in so far as sponsoring and producing Public Service Ads and other hand out literature. This does not mean that the law is not in need for some updating, but the law here should add to the potential of success and not look to punish for failure. There is a public interest in making sure that places where people congregate, shop, ride, teach and learn, are encouraged to be on constant vigilance mode. There is no simple problem as “just one bedbug.”

Property managers and tenants should know it is as dangerous to drag an unenclosed mattress through a building’s public areas, as it would be if the mattress were smoldering. An insect will easily drop off an infested mattress in the building hallway and could easily escape to another apartment. Furniture discards should be arranged in advance. Furniture as well as mattresses should be well-wrapped before disposal.

All that requires more widespread and consistent information. Government should be able to handle that. Community groups and tenant associations should be able to distribute literature and post flyers to spread awareness.

New York City has a statute relating to the mandatory eradication of pests insects and rodents. It would seem from a straightforward reading of the statute that there is a shared primary burden on the tenant and the landlord to assure the mandatory eradication of these pests. In some way we may still be of the mindset that every one of us knows the proper way to rid their home of those unwanted annoyances. However the literature associated with pest control suggests that amateurs should not deal with the problem. On the flip side, it should be clear that the landlord has the primary burden for eradication of pests where the problem is beyond any one “dwelling.”

Occupant in control

New York vs Bed Bugs: Finally, what is this business of “occupant in control”!? Please help us out with this. The New York City Housing Maintenance Code, is it a relic from just this era we’ve been discussing? What does this confounding phrase mean?

Steven W. Smollens: I have to agree that there is no sound reason for continuation of arcane language, especially when we need certainty as to who is in charge of pest control and maintenance of the structure. In a positive light, the “occupant in control” should be the same as “owner” and that may bring the attention of the Office of Code Enforcement upon the owner’s registered managing agent, the building’s superintendent, a net lessee of the building owner, a subtenant of a net lessee in control of the entire property. Perhaps it is a way to make more persons and entities associated with “owner” as responsible as the “owner” for keeping “…the premises free from rodents, and from infestations of insects and other pests, and from any condition conducive to rodent or insect and other pest life…”

That expansion to other responsible persons or entities is a means to gain a useful court or agency mandate against a real person or the person or entity actually in charge. I do not see that the term encompasses “tenant.” The Housing Maintenance Code is able to use the word or term “tenant” when it means tenant. So the absence of the word “tenant” from this section implies persons or entities as like the “owner” in control.

Naylor, R. A., and C. J. Boase. 2010. Practical Solutions for Treating Laundry Infested With Cimex lectularius (Hemiptera: Cimicidae). Journal of Economic Entomology 103 (February): 136-139. doi:10.1603/EC09288.

In keeping with our recent interest in the first line of these research abstracts, here is this one:

The common bed bug, Cimex lectularius (L.) (Hemiptera: Cimicidae) is known to become associated, from time to time, with clothing or linen.

From time to time…

The author surveyed 100 websites offering information on bed bug control in 2007, and found specific, practical information lacking.

Washing

3.2 kg dry weight of laundry, about 7 pounds, washed at 30°C/86°F, 40°C/104°F and 60°C/140°F in a 90-minute cycle wash (that’s the standard cycle in the UK) with a standard laundry detergent. Bed bugs (10 adults, 10 third instar nymphs, 10 eggs) were placed inside clothes pockets, in cotton pouches and sealed with a sandwich bag clip.

The 40°C/104°F cycle killed all adults and nymphs, but 75.6% of the eggs survived.

The 60°C/140°F cycle killed all stages.

Tumble drying

7 pounds of laundry (dry) in dryers set to “hot” and “cool” for 10 minutes and 30 minutes.

The temperature in the “cool” cycle never got above 30°C/86°F.

The 10-minute “hot” cycle did not kill all bed bugs, probably because it took more than 15 minutes to get above 40°C/104°F. (The authors reference the published thermal death point from previous work in the 1930s-40s in the range of 40-45°C/104-113°F.)

30 minutes in the “hot” cycle killed all life stages.

Here is a graph of the temperature logged during these drying cycles. The 40-45°C zone is the (previously published) dead zone, but it took more than 15 minutes.

temperature change over time, hot (A) and cool (B) drying cycles - Naylor & Boase 2010

Cold soaking

7 pounds of laundry in about 15°C/59°F tap water, without detergent.

Almost nothing dies if soaked for two hours. But, interestingly, all adults and nymphs died when soaked for 24 hours.

The eggs, however, survived. All of them.

Dry-cleaning

Professional dry cleaning with perchloroethylene.

100% kill of bed bugs and eggs.

Freezing

A laundry bag of 2.5 kg (about 5 and a half pounds) in a freezer drawer of a standard household freezer with a minimum temperature of -18°C/-0.4°F — a separate test was done with bed bugs placed in pouches in the freezer for two hours at -17°C/1.4°F.

2 hours at -17°C/1.4°F killed all bed bugs and eggs when placed directly (not in clothes) in the freezer. But when a bag of laundry was placed in the freezer, it took about 8 hours for the temperature at the center of the bag to reach -17°C.

The researchers advise caution about the regional differences in laundry equipment:

[T]here are regional differences in the operation and performance of domestic appliances that stress the importance of understanding the local situation when making recommendations. For example, washing machines in Europe typically heat their water to the user-selected temperature, whereas washing machines in the U.S. and Australia tend to use the household hot water supply and are therefore limited by the temperature of the water coming from the boiler. Furthermore, wash cycles in the U.K. typically last 90-120 min, whereas in the U.S., wash cycles of 20-30 min are much more common (Procter 2000). As Tables 1 and 2 demonstrate, differences in temperature and duration may make the difference between success and failure in terms of clothing disinfestation. These differences emphasize the need for caution when considering adopting advice generated in one country, for use in another.

For comparison of these results with some American laundering tests reported by Potter et al. in 2007, see this PCT article.

Q&A

Richard Naylor is a doctoral student at the University of Sheffield (UK). Take a look at his bed bug photographs here. I particularly like this one:

Bedbug. Copyright Richard Naylor.

He generously answered our questions via email.

New York vs Bed Bugs: Your group regularly produces some of the most fantastically interesting research about bed bugs and yet I have to say it is a joy to ask you about something as simple as laundry. Because in fact it is not so simple… so it is wonderful that you took an interest in this subject. I like that your study shows that people have options (e.g., you can disinfest clothing even if you don’t have access to a dryer), but you note that regional differences in laundry equipment are important to consider. So, with that in mind, if we were to make judgments based on temperature and time (in places where one doesn’t really know the temperature of washers and dryers but can use, say, a household thermometer for some limited testing), what would be a useful rule of thumb? Often people are confused by thermal death points, especially because they seem not to be stable in the literature and have much to do with method and duration of exposure.

Richard Naylor: The important thing does seem to be the temperature, whether washing or drying. 40 degrees [Celsius] seems to be the magic number. In simple terms this is about the temperature of a nice warm bath, so it doesn’t need to be scolding hot. Some washing machines don’t heat their own water and so the maximum temperature they can achieve is the temperature that the boiler is set to. If your hot tap produces water that is slightly too hot to hold your hands under for any length of time, it is probably fine for killing bedbugs. Unfortunately one can’t get round having to know something about their washing machine if they plan to use it for treating bugs. Perhaps it would be simpler to fill the bath with hot water. As long as it is a bit too hot to hold your hands in it should be fine. Hot water penetrates the fabric much quicker than hot air, so time isn’t really a factor as long as all the air is pummeled out of it.

New York vs Bed Bugs: Did you really read 100 bed bug fact sheets on the internet? I am honestly impressed by that diligence because that sounds like torture to me. Did you find great variability in the practical information on offer?

Richard Naylor: Yes I did. A lot of the sites offering advice were run by local councils. The advice wasn’t particularly variable because people just republish the same “knowledge” over and over again. I just kept a tally of every mention of “hot wash”, “tumble-dry” etc. and worked my way down a google search. Every now and then you stumble over a blinder, involving a bloody steak and a roll of sellotape, which keeps the motivation up! I keep a folder on my computer of all the best bedbug misinformation I can find on the web!

New York vs Bed Bugs: Can I ask you what you are working on? What are some of the interesting questions in need of answering?

Richard Naylor: I am currently interested in their ecology and dispersal. We actually know a lot more about the ecology of swallow bugs than we do of bedbugs, simply because when an infestation is discovered, it is normally treated straight away. People don’t want to wait a few weeks for studies to be made and experiments carried out. The solution I have come up with is to build about a dozen 3 meter long arenas complete with blood feeding station and around 200 bedbugs in each. I am trying to understand how they behave in an infestation and to figure out what factors are important in driving their dispersal.

New York vs Bed Bugs: I once saw what looked like a carved wood panel of mating bed bugs at your university’s website (can’t seem to find it again)—I am curious about just how old that is? Is it an artifact of the current interest in bed bugs or is it from much earlier? It is beautiful and I wonder if you’ve always had it.

Richard Naylor: Well spotted. We (though not me) started studying bedbugs at Sheffield University about 15 years ago. Mike [Siva-Jothy] used to be particularly interested in sexual conflict, which is the idea that males and females of a species are purely out to do the best for themselves as they can, often at the expense of the opposite sex. Bedbugs are a prime example, as males will mate with females much more often than the females require to stay fertile and as a result the females live about 25% less long than they would otherwise. We believe that traumatic insemination arose out of sexual conflict as a way of males preventing females from exerting choice over paternity.

Anyway, the carving was commissioned about 6-7 years ago and is made up of lots of images from old books and photographs around the department. The bedbugs are copied from an electron micrograph that we had done of some of our bugs at the time.

From the press release:

Fang Zhu, a post-doctoral fellow at UK along with fellow UK entomologists Mike Potter, Ken Haynes and Reddy Palli and several students, analyzed 110 bed bug populations from across the United States and found 88 percent of them had one or two genetic mutations. These mutations produce what is known as knockdown resistance, meaning the insecticide is not able to kill bed bugs.

[...]

“We need alternative insecticides to fight this bug,” Potter said, “Unfortunately today’s products are not as effective as ones we had previously. Non-chemical measures are important but are seldom completely effective and can be laborious and expensive. History has taught us insecticides are a crucial part of the bed bug solution.”

Data from this study will help pest management professionals make future decisions.

“The methods and primers developed by this group could be used to tell pest control professionals whether or not pyrethroids work on certain bed bugs by looking for these genetic mutations in the bugs’ DNA,” Palli said. “If it’s a target-site mutation, like the majority of these, spraying probably would be ineffective, but if it has another type of resistance, we could possibly add synergists to the current insecticide to help fight them.”

kdr-type mutations cause resistance at the pesticide target site via a mechanism of nerve insensitivity. (For an accessible explanation of pesticide resistance, I refer you to our interview with Dr. Alvaro Romero last year.)

For organochlorines and pyrethroids, these target sites are nerve sodium channels. Thus, DDT resistance can lead to pyrethroid resistance, as both pesticide classes act on the same target site.

As this study is not yet available, I reached out to the University of Kentucky researchers for clarification of the potential meanings of these findings.

New York vs Bed Bugs: Your study shows that the two mutations identified by Yoon et al. (2008) in a NYC population are actually widely prevalent in the United States?

Reddy Palli: Correct, more than 80% of populations showed the presence of one of these mutations.

New York vs Bed Bugs: In the press release you indicate that pest management professionals might use this information to determine a course of action. Can you confirm if UKY’s NYC and Cincinnati bed bug populations are among those with kdr mutations in your study?

Mike Potter: Some of the populations we tested from Cincinnati had one or both mutations while a few others did not (both of the latter still showed high resistance to pyrethroids in bioassays, however, suggesting that other resistance mechanisms may be involved). As far as the NYC populations we tested, all (12) had one or both mutations for pyrethroid resistance.

New York vs Bed Bugs: Are kdr mutations predictive of cross-resistance with other pesticide classes? I note that DDT conferring resistance on modern populations is stated as a possibility (but does this require further investigation?), but what of other possible cross-resistance possibilities?

Reddy Palli: Insecticides (eg. DTT, BHC) that use sodium channel as a target site likely show resistance. As you say, this requires further investigation. Insecticides (eg. Phantom and Propoxur) that work through target sites other than sodium channels may work fine on these resistant populations.

Mike Potter: Unfortunately, we just don’t have too many of these presently that have residual activity as a dry deposit other than products like Phantom (chlorfenapyr), desiccant dusts (e.g., silica gel, DE), and to a degree, the IGRs. Propoxur would be another but the decision to grant it a Section 18 emergency exemption is up to EPA.

New York vs Bed Bugs: I think the public may misinterpret this study as confirmation that “pesticides don’t work” — which is not really the case.

Mike Potter: I think it may be a bit too strong of a statement to conclude that pyrethroids “don’t work” on most of the bed bug populations in US, as we often do kill a percentage of the individuals we test in the laboratory, especially when they are contacted directly with the wet spray deposit. Dry residues typically kill far fewer and we know this to be important for optimal performance of products in the field. Reports from many pest control firms further indicate the pyrethroid products are not performing as well as they would like. Some companies continue to believe that they are working ok, but generally these companies are also incorporating additional treatment measures such as the use of contact killers (Sterifab, Bedlam, Phantom aerosol, etc.), steam, encasement of beds, etc., making it hard to know what specifically is working.

__________________________________________

I thank Dr. Palli and Dr. Potter for so kindly taking the time to answer my questions.

This is most definitely bad news; however, we have been expecting as much and indeed researchers at the University of Kentucky have been warning of widespread pyrethroid resistance for years. Having this confirmed, on this scale, is still a blow. The urgency of having options to enable the most basic resistance management countermeasures should be obvious.

Perhaps I should remind you that today is the last day of the public comment period for Ohio’s Section 18 propoxur exemption request under consideration by EPA.

1. 4/10 – the article has been published: Zhu, Fang, John Wigginton, Alvaro Romero, Ali Moore, Kimberly Ferguson, Roshan Palli, Michael F. Potter, Kenneth F. Haynes, and Subba R. Palli. 2010. Widespread distribution of knockdown resistance mutations in the bed bug, Cimex lectularius (Hemiptera: Cimicidae), populations in the United States. Archives of Insect Biochemistry and Physiology 73, no. 4: 245-257. doi:10.1002/arch.20355.

Pretty neat, yes?

For one thing they’re dead, but still look pretty good, and there they are, all stages, clearly visible! An elegant educational tool, simple and, one can hope, inexpensive.

Dr. Gerry Wegner is technical director and staff entomologist of Varment Guard Environmental Services Inc. in Columbus, Ohio. He very generously answered our questions.

New York vs Bed Bugs: I think this is very, very cool. How is this made?

Gerry Wegner: Sometime back one of our company technicians brought me an open bottle of Dial hand sanitizer that had fruit flies suspended in it and they stayed perfectly preserved since that time. I checked the ingredients and found that hand sanitizer is @ 65% ethyl alcohol, which is great for preserving most insects and spiders. However, I actually place live specimens in 75–80% alcohol to allow body fluids, waste and visible contaminants to be expelled and then I transfer the fixed specimens to display vials filled about 2/3 way with hand sanitizer.

Next, I remove air bubbles with a fine-tip dropper. Then I place the fixed specimens into the vials and situate them in the position I want using long, fine-tip forceps. I add more hand sanitizer as I go. I top off the vials and remove the last of the bubbles, slide a printed label along the inside wall of the vial and seal it with a tight-fitting cap. More air bubbles sometimes appear over time; but they can be removed with the dropper and the cap replaced. Vials can be purchased from BioQuip (www.bioquip.com).

New York vs Bed Bugs: What is your experience of people’s reactions to seeing bed bugs?

Gerry Wegner: Lots of folks get grossed out over bed bugs’ appearance but they want to see them anyway so they’ll know how to recognize them. Having specimens dead in hand sanitizer helps calm folks’ fear of contact. I keep a live colony for display and research as well.

New York vs Bed Bugs: Do you think we’ll get a handle on this bed bug problem, Dr. Wegner?

Gerry Wegner: In my opinion, we’ll always have bed bugs surviving somewhere in the U.S., sort of like background noise, no matter how diligent the general population becomes with caution/prevention and remediation or IPM technology advances.

____________

Background noise. We’re there, sadly. I know people in the city who are already quite used to bed bugs.

Check out Dr. Wegner’s article about this technique:

Wegner, G. S. (2004) A Surprising New Medium for Specimen Preservation and Display American Entomologist 50:4, 220-221. (free PDF download)

The bubbles—an issue in display aesthetics only—can be teased out using a probing instrument or will rise to the surface over time.

New York vs Bed Bugs: Can you tell us about the severity of the patient’s condition and why it was caused by bed bugs? This was a life-threatening condition?

Dr. Stephen W. Hwang: The patient had severe anemia (a very low level of red blood cells) because he had an extensive bed bug infestation in his apartment that had gone untreated for months. This man was losing a substantial amount of blood on a daily basis to the thousands of bed bugs living in his bed and mattress, to the point that he became iron deficient. His blood levels reached a very low level that could be described as potentially life-threatening, although fortunately he did not suffer any permanent damage to his health. As we describe in our report, we are quite certain that the bed bugs were the cause of his anemia because an extensive series of medical investigations did not reveal any other source of blood loss or an alternative explanation for his anemia. In addition, his anemia went away and did not return after his apartment was treated for bed bugs.

New York vs Bed Bugs: The patient’s bed bug infestation has been abated but not eradicated. Presumably he is still at risk should the infestation grow to previous levels. Have you any indications of the prevalence of persistent bed bug infestations in the vulnerable populations which are the subject of your research interests? And what are the implications for the care of individuals who are at higher risk for chronic bed bug infestations? What would you recommend to health care providers?

Dr. Stephen W. Hwang: We have not done a follow-up study to find out if bed bug infestations are more common than before among vulnerable populations such as people living in homeless shelters or residents in low-income housing. In my experience as a physician caring for patients who are homeless, I would say that the problem of bed bugs has become even more prevalent over the last 5 years. Although many people complain about bed bug infestations, and rightly so, I think that the main point of our case study is that we should be keeping our eyes open for those individuals who have bed bugs in their home and are not complaining about it, for whatever reason. I suspect that people who have severe mental illness, addictions, or cognitive impairment (such as dementia) are at highest risk of developing overwhelming bed bug infestations. Health care providers need to familiarize themselves with the symptoms of bed bug bites and infestations, and be prepared to give advice on how to deal with this problem.

New York vs Bed Bugs: Aside from severe allergic reactions, there is little evidence in the medical literature for any of the potential health risks that have been suggested for bed bug infestations. It’s an open question, however, whether there is awareness and capacity to detect effects. In the years since your Toronto survey of bed bug infestations, what has been the interest in and perception of bed bugs in the medical and social services communities?

Dr. Stephen W. Hwang: Over the last 5 years, I think bed bugs have changed from being a new and unfamiliar problem to one that many health care and social service providers are very accustomed to seeing. Since this is a problem that shows no sign of going away, we need to prepare ourselves for a continuous and sustained effort to improve the control of bed bugs, rather than expecting to “defeat” or eliminate them. The risk is that we can’t afford to become either complacent or hopeless in this ongoing struggle. I also believe that we need to devote more resources to ensure that people who don’t have the capacity or resources to deal with bed bug infestations in their home can get the assistance that they need.

Publications:

Pritchard, M.J. & Hwang, S.W., 2009. Severe anemia from bedbugs. CMAJ, 181(5), 287-288. doi:10.1503/cmaj.090482

Hwang SW, Svoboda TJ, De Jong IJ, Kabasele KJ, Gogosis E. Bed bug infestations in an urban environment. 2005. Emerging Infectious Diseases 11(4), 533-538. http://www.cdc.gov/ncidod/EID/vol11no04/04-1126.htm

New York vs Bed Bugs: We are very impressed with the task force and understand it’s a volunteer organization?

Paul Wenning: We’ve known it was just a matter of time before bed bugs became a large problem in Greater Columbus. I had a series of conversations with officials from Cincinnati and Hamilton County (Greater Cincinnati) in the early autumn of 2008, and the astronomical rise in the number of cases there over a five year period convinced me that we had to take action and quickly. I began conversations with Dr. Susan Jones, from the Ohio State University Extension Office, who is also a leading expert on bed bugs. We quickly created a Bed Bug Summit, to which representatives of the City of Columbus, the suburbs, and County agencies were invited. It was well attended, and at the end of the program, I asked for volunteers to help establish a Bed Bug Task Force for Columbus and Franklin County. We held our first meeting in November, and I set forth a series of goals and objectives for the group to discuss. They were:

• Develop consistent messages for the residents of the area concerning bed bugs;
• Develop methods to educate our communities about bed bugs;
• Dispel the myths surrounding bed bugs;
• Target groups and populations who were at the greatest risk of getting or spreading bed bugs.

The group members agreed with those goals with some modifications. We immediately established subcommittees composed of people with real experience for each of our target communities, including rental housing, and code enforcement; schools, hotels and transient housing, public safety, health care, and social service agencies, and media outreach / public education.

We also committed to the development of a website. Our agency agreed to fund the development and maintenance of the site, but we made it clear that we would rely on the other members for content. I’ve been pleasantly surprised by the enthusiasm and hard work that our members have shown.

New York vs Bed Bugs: How many agencies and stakeholders are actively involved in the task force? What are the jurisdictional areas? Columbus and surrounding counties?

Paul Wenning: Right now, we are restricting our focus to Columbus and Franklin County. We’ve had requests from the City of Dayton, and from smaller communities in the outlying counties to join the COBBTF, but frankly, since this is a voluntary effort, we just cannot coordinate anything larger than we have at present. That may change in the distant future, but it would require significant funding first.

Our area is a hodge-podge of local jurisdictions. We have the remnants of 17 townships left in the county, 12 or more communities that are cities (populations > 5,000 – though most of them far exceed that figure) under the Ohio Revised Code, the City of Columbus, and a few small villages. Each community has its own school system, fire and police departments and code enforcement officials. Our health department serves all of the communities with the exception of Columbus. It has its own health department.

Our total population is about 1.2 million and growing. Our population is very diverse. We have a large Somali population, a very large Hispanic population, a sizeable Asian population, and growing Pakistani and Indian populations.

At present, members of the COBBTF represent:

• 4 local fire departments;
• Code Officials from the City of Columbus and 5 suburbs;
• School nurses from Columbus and the Cities of Westerville and Upper Arlington;
• Representatives of the pest control industry (5);
• Representatives from the rental housing industry (mainly property managers and maintenance staff);
• The Central Ohio Agency on Aging;
• Ohio State University Student Housing;
• The Urban League;
• Franklin County Job and Family Services;
• OSU Extension;
• The State Departments of Health (schools, nursing homes), Agriculture (pesticides), Commerce (used furniture and hotel licensing);
• The City of Grove City Travel and Tourism Board;
• Franklin County Office on Aging;
• Franklin County Legal Aid;
• Franklin County and Columbus Health Departments;
• Local hospitals.

I’m sure that I’ve forgotten several people. They are listed on the web site under the partners tab.

New York vs Bed Bugs: At the EPA bed bug summit we heard there was disagreement about what to do. How have you coped with the potential for similar disagreement within the task force, particularly with such a large number of volunteers?

Paul Wenning: We haven’t had too much disagreement within the group. By keeping our general goals and objectives broad enough, and by vesting the responsibility for each subcommittee to decide how they will address the issues in ways that are productive to their constituencies, I think that we’ve avoided all of that. When the COBBTF first formed, I made it clear to the subcommittee chairs that we considered them to be the experts at reaching their populations. We (the Steering Committee) exist to help them achieve their objectives. And we’ve hewn to that philosophy. I think it has made a huge difference in the way that the Task Force has operated.

New York vs Bed Bugs: What is the legal framework for landlord/tenant bed bug issues in the task force’s areas of operation? Is there clarity on rights and responsibilities? I’ve been reading about the Columbus Apartment Association’s new rules and regs, and I’m troubled by the lack of clarity and potential to blame tenants, which should predictably result in decreased reporting of bed bug infestations. These situations usually spell disaster for control efforts.

Paul Wenning: As far as enforcement, bed bug complaints are handled by the Franklin County Board of Health (outside of Columbus) and Columbus Code Enforcement in the City. We’ve held several meeting with one another and we have adopted very similar enforcement strategies, in order to present a consistent message to our residents. Bed bugs are considered a nuisance under the Ohio Revised Code, and we must always name “the property owner of record” in any enforcement action that we take. However, we also name the tenants in the complaint if they are recalcitrant and refuse to assist the landlord in his or her efforts, by maintaining their unit in a clean and sanitary condition, encasing mattresses, etc.

The Columbus Apartment Association developed a document on its own that is now in circulation on the web and that is being disseminated by its representatives. The document has been submitted to the COBBTF Housing Subcommittee for review and amendment, but it is NOT a COBBTF document, and some of our members, especially from tenant’s right’s groups will not accept it without significant revision so that it is more balanced. The Housing Subcommittee members have told me that they think that the basic information is useful, but that they expect that it will be some time before a final draft is submitted to the Steering Committee.

New York vs Bed Bugs: What sort of challenges have you identified? There’s the gamut of bed bug problems, resources, legal issues, access to bed bug control services. In NYC one of the most challenging problems is access to pest control services. Another sort of intractable problem here is posed by refurbished mattresses. What are yours?

Paul Wenning: Our biggest challenges are: 1) Lack of funding; 2) Used mattress and furniture dealers; 3) Apathy; 4) Lack of personnel; 5) Availability of pest control for poor residents. In short, the same issues that you have!

New York vs Bed Bugs: Are you tracking infestations? What are the available statistics?

Paul Wenning: We haven’t developed a good tracking system yet. We’re working with Columbus Code Enforcement to develop a system, but it will take us awhile. We are informally tracking numbers now, but we do want to get a sysem together as soon as we can.

New York vs Bed Bugs: What are the critical needs? What can the people of Ohio and others, state legislators and federal agencies, do to help?

Paul Wenning: I’ll have to think more about what we need the most. Information is always helpful. A new USEPA policy allowing the use of restricted pesticides would help. Money for pesticide treatment for low income residents and senior citizens, and education and outreach would help, too. I’d also like to see the State Legislature place significantly stronger restrictions upon the sellers of used furniture and household goods that would require them to PROPERLY treat items before they are placed for sale, and would restrict ANYONE from selling discarded furniture that they collect from the alleys or dumpsters. Right now there are no restrictions upon that activity.

That’s the “short list.” I’m sure I’ll think of more.

This conversation is 54 minutes; you can also listen to it on itunes.

And if you look to your right you’ll see a short video clip (5 min) of our call.

We’ve talked to David a couple of times previously, see our first interview, the highlights of the first interview and our second podcast.

Lou answered our questions via email.

New York vs Bed Bugs: You talk to many New Yorkers, thousands I’m sure by now, who are struggling to cope with bed bugs. What are some of the issues that they are concerned about and seek your advice on?

Lou Sorkin: People wonder if they can trust canine detection especially if the dog is owned by the pest control company. How can different dogs working in the same apartment give different answers. Basics on what to do if an infestation is discovered. Also want to bring in collected insects or various materials for identification. In doing so, some other insects or mites have been identified and it’s comforting to people to have bird or rodent mites rather than bed bugs living in their apartment!

Most people are not equipped to deal with bed bug infestations because they have been “spoiled” by normal pests such as cockroaches, ants, beetles, moths. A bed bug infestation requires more physical involvement on behalf of the homeowner or tenant, something they are not used to doing in combatting other pests. Of course, the expense is also one thing that people also are not equipped to handle, but it is more labor intensive and it does disrupt your life and you don’t want it to happen multiple times.

The managing agents or owners have to realize that treating one complaint (or apartment) at a time is not the way to go. It will be more expensive in the long run. I’ve worked with coop & condo boards, too, who are wrestling with the problems involved with bed bug infestation.

New York vs Bed Bugs: What do you think might be essential components of an education campaign for the city? I know you feel very strongly about identification of nymph stages and the problem of an inaccurate search image.

Lou Sorkin: That’s true. Even at the EPA meetings and the news coverage, images of adults were typically shown as “the bed bug”. Need to educate the public that bed bugs are not always 1/4 inch long and reddish brown in color. A newly hatched nymph is 1/32 inch long and pale to white in color. The thickness of a credit card is about the length of a newly hatched bed bug nymph. If you have the wrong search image, you have an infestation that you cannot locate by visual means alone.

When there are public lectures of some sort at the museum, I have bed bugs in addition to the spiders and insects that are normally shown to people. On occasion, I’ve attached the microscope camera to my laptop and show the live colonies on a large plasma screen for the audience. I’ve taught in the elementary schools and at the Science and Nature program at the Museum various sections on biology of insects and spiders and also bed bugs because children may know more about what’s crawling about than their parents do. I’ve also spoken to physicians about insects and arachnids and, of course, bed bugs so they understand about the various bite reactions one can experience that could very well not fit the “textbook” view that they probably learned in college.

New York vs Bed Bugs: What else should we do to combat bed bugs? I know you have thoughts on the high volume of discarded infested furniture and mattresses.

Lou Sorkin: I can’t understand why in a city like New York (or other cities, for that matter) people throw so much stuff away that could be treated. Why hasn’t a business materialized that collects the furniture, mattresses, box springs, and treats these objects to kill all the bed bugs and eggs. Heat treatment, true fumigation all will work. Mattresses and box springs can be recycled (the mattress and box spring can be dismantled according to the rep from the bedding industry who spoke at the NYC city hall meeting) or why not properly treated (my opinion, not industry rep’s, if in good shape) and covered (with correct encasement). Mattresses and box springs in perfect shape can be encased by the tenant or homeowner. The treated furniture can be dismantled and washed down and reassembled and resold. Can even use dogs to assess before reselling. The money from the sold goods can be reinvested into the funds needed to help people who cannot afford bed bug treatment. The furniture can be given to those who need it.

People feel that pest control industry is making so much money on bed bug treatment and I’m sure many in the industry would donate a small percentage to a fund that could use the donations to fund research, public service announcements, assist in bed bug remediation for those who have trouble affording it, assist people who need help in readying the home for bed bug treatment. The industry is really not limited to pest management but also mattress encasement manufacturers, do-it-yourself companies, in fact, all related businesses that profit from bed bugs.

New York vs Bed Bugs: Perhaps you can tell us about the infestations you are called on, the difficult ones that will always pose a challenge.

Lou Sorkin: The difficult infestations are usually those that have been overlooked and have grown to large ones and ones that have crawled into adjoining apartments (in the case of multi-family dwellings). Part of it is attributable to the tenant(s) not knowing what is going on either due to that person’s mental state, age, or who really needs social services in general. People have the wrong idea about bed bugs and do not want to report the infestation for fear of alerting others that he/she is “dirty” or that other tenants will be angry or the landlord will evict him/her. All of this and more prevents early detection. Also management agents who rely on tenants to alert them to bed bug infestations are notified when the infestations are already entrenched in the apartment or building. They have to be proactive, use early dectection techniques, including canine detection. When an infestation is located, examination of adjacent apartments is crucial to controlling the problem. Treating that one apartment for the infestation may only control the infestation in that apartment or it could soon be reinfested by bugs from adjacent apartments.

One cannot rely solely on pesticide treatment, something people probably have with respect to cockroaches and ants and the use of baits. IPM approach to pest management is required and sealing and closing access points is important for bed bug control. Washing/drying or just drying clean clothes and isolating these prior to treatment is important. Also don’t surf the Internet and buy potentially ineffective or dangerous controls because you feel completely helpless. Bedbugger.com is one site that provides good information and discussion and up-to-date reports from around the world on bed bugs.

New York vs Bed Bugs: Where do you come down on the controversial question of whether additional training is necessary for pest control technicians?

Lou Sorkin: Yes, I think that specialized training classes are needed for technicians. Maybe some do not want to give away their secrets and not give competitors the upper hand. Some PCOs tell me that they are often contacted when others have already done the work and have not taken care of the problem. I’ve taken recertification courses in various aspects of pest control over the years and there are extremely knowledgeable teachers and there are not. All have provided the NYS DEC with course information to register the course and I don’t know if any have ever been rejected, but should have been in my estimation. Maybe it looks good on paper, but the actual presentation is lacking any worthwhile content. The teacher gets paid by the people taking the class, the students receive CE credits, but they haven’t learned much at all or have learned incorrect information. A good class with input from pest control personnel and entomologists can be made as a standard, perhaps. Also on the subject of classes, hotel personnel, superindents, realty agents, dormitory staff, school staff, hospitals, medical offices, general business maintenance personnel should be taught to look for telltale signs, though this is not restricted to actual bugs, but also shed skins, eggs, and fecal drops, in order to locate infestations early and institute surveillance and remedial action.

Detection dogs are also recertified regularly and people should check that out with the company that handles the dogs. Handlers gain knowledge with experience and also time with their dog and will learn more about dog behavior as they go. It is also extremely important that the handler mark and later return to places where there have been alerts. The canine inspection process should not be one where the dog alerts and the handler and dog leaves you with a bill. The dog is alerting and telling you where to look. The area in question (whether it is a piece of furniture or pile of clothes, and so on) must be examined to reveal bed bugs. There may be other insects, it could be a false positive. The recertification process tests the dogs in many ways: if a dog fails, it has to be retaught.

New York vs Bed Bugs: Tell us about the EPA meeting. Did you find it productive? Can a course of action be settled on amid such diverse and sometimes conflicting interests?

Lou Sorkin: It was a productive meeting because there were diverse and conflicting interests. The forum was open and people could voice their opinions and could be heard: there was no judging.

In attendance were people and researchers associated with many different avenues of bed bug research and control, so there was available much knowledge from all of them. The 275-300 attendees were divided into 10 groups in order to discuss the issues and come up with answers to questions. The answers were amazingly similar from the workgroups and these were presented to all on the last day of the conference.

Since there are many disciplines involved with bed bugs, some of which are not immediately identified with infestations, all can assist in combatting bed bug infestations.

We have long read about his research with avidity and the hope that we might have a chance to talk to him about bed bugs, resistance and other difficult bed bug topics.

Alvaro Romero very generously answered our questions via email.

New York vs Bed Bugs: Let’s start with a shamelessly frivolous question, just because no one would ask you this except us.  How are bed bugs fed at the lab?

Alvaro Romero: We feed our bed bug colonies with an artificial membrane feeder; this means there are no human subjects involved in this activity. We feed the bugs weekly on warmed animal blood supplied by a research supply company. Colonies remain in environmental chambers at constant temperature and humidity conditions and they are subjected to a specific light-dark cycle. This system allows us to rear, in the lab, several colonies collected from different areas across the country. Several graduate students working in our lab at the University of Kentucky are currently conducting experiments with bed bugs.

New York vs Bed Bugs: How do pyrethroids affect bed bugs? That is to say, how are they supposed to work?

Alvaro Romero: Pyrethroids negatively affect the nervous system of insects. In insects susceptible to pyrethroids, nerve transmission is disrupted. This toxicity in bed bugs is expressed with intense hyperactivity, incoordination, paralysis and/or death.

New York vs Bed Bugs: What happens when pyrethroid insecticides don’t kill bed bugs? And what are the likely or known mechanisms of resistance?  Are bed bugs detoxifying insecticides, becoming insensitive to them, avoiding them, or… what are the possibilities?

Alvaro Romero: Insects and various other arthropods have the potential to reduce the toxic effect of pyrethroids by becoming insensitive to them (mechanism known as target site insensitivity), by limiting penetration of the insecticide through their cuticle (skin), or by breaking down the insecticides with enzymes before the chemicals reach their target. Some of these resistance mechanisms have already been recognized in bed bugs.

Since our 2007 report in the Journal of Medical Entomology which sounded the alarm about seemingly widespread pyrethroid resistance in bed bug populations in the United States, we have been looking into which resistance mechanisms are involved. Suffice it to say that we are finding evidence that some bed bug populations have a very efficient enzymatic arsenal to detoxify pyrethroids. We further suspect that other resistance mechanisms are responsible for pyrethroid resistance in these particular strains.

On the other hand, in a recent paper, Yoon et al. (2008) examined the resistance profile of bed bugs collected from New York City (NY-BB). They identified two point mutations in one of the genes that codes for pyrethroid-sensitive neural structures. Bed bugs having such mutations would remain unaffected by pyrethroids; or, in other words, they are insensitive to them. So I think there is already compelling evidence that bed bugs have the ability to develop resistance to pyrethroids.

New York vs Bed Bugs: The simplest indication of resistance we found is predicated on observation, that is, the failure to control a pest with customary materials.  But by the time management failures occur, is insecticide resistance not already well-established?

Alvaro Romero: It is important to point out that there are factors other than insecticide resistance that may make an insecticide treatment ineffective, including 1) inability to have complete treatment coverage (e.g. excessive clutter, which makes hiding places difficult to reach, so some insects are not exposed to the insecticide), 2) reintroduction of bed bugs to the premises, and 3) tendency of bed bugs to avoid treated surfaces. Thus, treatment failure is not always synonymous with insecticide resistance. It is difficult to pinpoint when resistance begins. However, pest managers might suspect resistance when bugs persist in areas that they know were thoroughly and previously treated with insecticide.

New York vs Bed Bugs: Are there test kits for resistance available?

Alvaro Romero: There is a commercial kit (PDF) available to confirm resistance in bed bugs and other pests. Currently, however, no such kits are being marketed to the industry here in the United States.

New York vs Bed Bugs: How is insecticide resistance in bed bugs managed?

Alvaro Romero: Synergists are a good option to try to eliminate pyrethroid-resistant bed bugs. We know that the synergist, PBO, increases the toxicity of deltamethrin in some resistant strains. However, there are other resistant strains unaffected by such mixtures, and these are those which might be insensitive to pyrethroids, as I mention earlier. There are other synergists that have the potential to be used, but there is little research done so far on that issue. The other alternative is to include non-pyrethroid insecticides such as chlorfenapyr which is effective against resistant populations although its killing action is quite slow.

Given the fact that insecticide resistance is a threat and today there are not very many alternative insecticides, a sound recommendation is to incorporate chemical (residual and contact killer insecticides) and non-chemical methods in management programs, including vacuuming, heat treatment, and bed encasement, among others.

New York vs Bed Bugs: What is the suspected role of DDT or other pesticides long used against bed bugs in relation to the current occurrence of pyrethroid resistance?

Alvaro Romero: We know that there is cross resistance between DDT and pyrethroids in some of our lab populations. Whether this pyrethroid resistance seen today is related with DDT resistance reported since the 50’s is unknown.

New York vs Bed Bugs: Tell us about the resistance studies you have conducted, what levels of resistance have you found, and to which insecticides?

Alvaro Romero: We have tested bed bugs, collected from different parts of the USA, with dry residue tests and have found a very high level of resistance to deltamethrin in most of the samples. Resistance was also very high in one strain we exposed to lambacyhalothrin, which suggests cross resistance between pyrethroids, as has been observed with other insects. All these samples were collected before the location was treated with insecticides. You can find more information on the JME’s article and the PCT article.

New York vs Bed Bugs: You’ve also tested a non-pyrethroid currently in use against bed bugs, what have you found?

Alvaro Romero: We have tested chlorfenapyr, the active ingredient of “Phantom,” and although it is effective against all strains tested so far, its killing action is relatively slow. Bed bugs also generally need to rest on treated surfaces for longer periods of time compared to what is required with pyrethroid-type insecticides. The good thing is that bed bugs do not avoid chlorfenapyr-treated areas.

New York vs Bed Bugs: And is there any difference between technical grade (only the active ingredient) and formulated (the pesticide as sold) materials in your tests?

Alvaro Romero: The results between tests using technical grade and formulated material are generally similar. In the lab, in order to determine how susceptible or resistant a population is to a certain insecticide, and estimate accurately its resistance level, the active ingredient needs to be used. Similarly, when studying responses of bed bugs to insecticides it is crucial to determine whether the effect is caused by the active ingredient contained in the product or by some other component of the formulation (solvents, emulsifiers, etc).

New York vs Bed Bugs: Why don’t bed bugs acquire a lethal dose of the insecticide?

Alvaro Romero: They do not acquire a lethal dose for several reasons, including: 1) they are resistant to the insecticide in use, 2) bugs do not encounter treated areas during their search for a host at nighttime, 3) bed bug hiding places are missed during application or, 4) they avoid walking or resting on treated areas.

New York vs Bed Bugs: What is the risk of repellency, behavioral avoidance and irritancy in bed bugs?

Alvaro Romero: Insects avoid prolonged exposures to insecticides by moving away from the treated area either due to repellency (after perceiving insecticides at some distance) or due to irritancy (after contacting the treated area). In our studies we were careful not to talk about repellency, because our bioassays were not designed to determine whether bed bugs were detecting insecticide treated areas at some distance. Our results showed that bed bugs tended to avoid resting on pyrethroid-treated surfaces (unless there were harborage odors).

As far as irritancy, video taped recordings of bed bugs interacting with pyrethroid-treated surfaces during the nighttime indicate that irritancy (expressed as locomotor hyperactivity) does occur. Irritancy increases the chance of insects moving across insecticide-treated surfaces which would accelerate the acquisition of lethal doses in susceptible populations.

You can find more information on these results in a recent article published in the JME.

New York vs Bed Bugs: What is the influence of fecal-marked harborages in the efficacy of insecticide treatments?

Alvaro Romero: In our studies, bed bugs did not avoid contact with insecticide deposits applied to established harborages containing feces and bed bug odors. This shows us how complex the interaction between bed bugs and insecticides can be. In our studies, harborages remained attractive to bed bugs after being treated with a pyrethroid. This indicates that attracting factors of harborages (pheromones) were unaltered after insecticide treatment. And this is good because the continued occupancy of bed bugs in such treated areas might increase exposure to the insecticide.

New York vs Bed Bugs: Can these behavioral effects increase the risk of bed bugs spreading from one apartment to an adjacent apartment?

Alvaro Romero: If bed bugs avoid insecticide treated areas, they can move to insecticide-free areas. This fact plus increased locomotor activity caused by pyrethroids might partly explain why places adjacent to infested areas become infested as well.

New York vs Bed Bugs: Is there a relationship between behavioral effects of avoidance or irritation and susceptibility?

Alvaro Romero: In our studies we found that pyrethroid-resistant bed bugs tended to avoid sitting on treated surfaces. We have limited information on the relationship between avoidance-prone vs. susceptible strains. Nevertheless, our results show that insecticide avoidance and physiological resistance can coexist. There is still a long way to go before determining, with accuracy, if this relationship is a generalization in bed bugs.

New York vs Bed Bugs: What is known about mating, egg laying, and, of course, feeding, after acquiring a sublethal dose of insecticide?

Alvaro Romero: We know very little about these sub-lethal insecticide effects on bed bugs. What we do know is that hungry bed bugs crawl over treated surfaces to reach a blood meal and this short exposure to the insecticide is not enough to kill and prevent them from feeding and subsequently reproducing.

New York vs Bed Bugs: We do know that pest management professionals can still control bed bugs with pyrethroids. What do you think is happening that, despite resistance, control can still occur in many cases?

Alvaro Romero: We have no doubt that there are bed bug populations that can still be controlled with pyrethroids. We have to consider, though, that in many cases an ongoing resistance problem can be masked because pest managers apply other products beside pyrethroid sprays to control infestations, including contact killers such as alcohol- or solvent-based insecticides. Thus, even if you are dealing with resistant bed bugs, you can still reduce numbers of bed bugs or luckily eliminate the infestation with a contact killer—in the hypothetical case you could hit all individuals present. Fortunately, resistant bed bugs are not “immune” to the action of such contact killers. Bringing the number of bed bugs down quickly by using contact killers can give the impression that there is not a resistance issue. I am particularly worried, however, that despite multiple and thorough insecticide treatments, some bugs will persist, especially when there is an abundance of clutter. Those bugs are the ones that you could have missed with contact killers because they were not accessible at the moment of the treatment. Concealment is a critical issue in bed bug management, and that is why the use of an effective residual insecticide is desirable in control programs.

New York vs Bed Bugs: Can you tell us anything about additional projects you are working on?  Obviously we’ve heard that you are working on circadian rhythms.

Alvaro Romero: I am currently conducting studies on bed bug ecology to determine how environmental cues as light and temperature affect locomotor activity of females, males and nymphs. Additionally, I am also investigating how feeding status affects the frequency of movement during nighttime. Our bed bug team at the University of Kentucky is working on many other projects also, which hopefully will provide relief to those who are suffering as a result of this most difficult pest.

Cited:

• Romero, A., Potter, M.F., Haynes, K.F. 2009. Behavioral Responses of the Bed Bug to Insecticide Residues Journal of Medical Entomology. 46:1, 51-57. Full text and PDF available.
• Romero, A., Potter, M.F., Potter, D.A., Haynes, K.F. 2007. Insecticide Resistance in the Bed Bug: A Factor in the Pest’s Sudden Resurgence? Journal of Medical Entomology. 44:2, 175-178. Full text and PDF available.
• Romero, A., Potter, M.F., Haynes, K.F. 2007. Insecticide-Resistant Bed Bugs: Implications for the Industry Pest Control Technology. 38:7, 42, 44, 46, 48, 50, 143.
• Yoon, K.S., Kwon, D.H., Strycharz, J.P., Hollingsworth, C.S., Lee, S.H., Clark, J.M. 2008. Biochemical and Molecular Analysis of Deltamethrin Resistance in the Common Bed Bug (Hemiptera: Cimicidae) Journal of Medical Entomology. 45:6, 1092-1101. Full text and PDF available.