Entomologists Ignite in Denver: Part II.

In the first of my two posts about the annual conference of the Entomological Society of America (ESA), I covered some of the non-urban entomology sessions.  In today's post, I'll review some things that are a little more relevant to the business of pest control.

Technology and urban pests

While sitting through some papers at ESA that went way over my head, it occurred to me that entomology has changed a lot since I went to school. One of the biggest changes is in technology. Today's technology is much more sophisticated, and enables us to study insects in ways we could only dream of a few years ago. For example, our ability to amplify minute amounts of DNA from an insect's stomach lets us know what kind of bacteria live there, or what the insect's last meal was. Amazing.

Wooden stake with Formosan termites. Unlike drywood termites,
which get their nitrogen from the air, subterranean termites
appear to get their nitrogen from ingesting soil. 

In one sense, this growing sophistication is a good thing.  It means that researchers now have better tools to understand the basic biology of insects.  On the other hand, there appears to be a trend in many universities to shy away from practical applied research and focus more on shiny new techniques and tools. In hallway conversations with industry reps, I'm told it's easy for hiring companies to find a young entomologist who knows her way around a genetics lab, but increasingly hard to find one who knows their way around a cockroach-infested apartment or a PMP's tool box.

One of my favorite student papers, with a balance of good basic science and applied biology, was also one of the shortest.  Aaron Mullins, University of Florida, explained in his three minute (!) paper that biologists have long known that drywood termites get much of the nitrogen (N) they need from the air (N is an essential element for protein building and reproduction). This makes sense because drywood termites live entirely in relatively low N-containing wood. Mullins wondered if the same was true for subterranean termites. He found that Formosan termites housed in organic (N) rich soil grew their colonies 10X as fast as similar colonies living in clean sand. He concluded from this and other evidence that subterranean termites get their N from the soil rather than air.  I'm not sure of the long-term impacts of this new discovery, but it will likely affect how we rear termites in the lab for experiments.

Jose Pietri with Apex Bait Technologies gave an interesting paper with potentially big implications. Testing the hypothesis that symbiotic gut microbes might play a role in cockroach resistance to insecticides, Pietri and colleague Dangshang Liang fed insecticide-resistant cockroaches a bait mixed with an antibiotic, doxycycline. They found a significant  increase in mortality from the bait with doxycycline compared to bait without the antibiotic. When the antibiotic bait was fed to insecticide-susceptible strains, however, it was no more effective than the bait without antibiotic. If confirmed, this might prolong the usefulness of some insecticide active ingredients for resistant cockroaches.

Ed Vargo, of Texas A&M University, reported that tawny crazy ant, Nylanderia fulva, infested five new Texas counties in 2017, bringing the current total to 39. He found that ants from different crazy ant colonies were not aggressive to one another, and he used sophisticated genetic tools to discover that there were no significant genetic differences among nests in a site or between states. These data suggest that TCA has extended colonies that might range over many miles.  This diffuse nest structure, similar to Argentine ant, at least partly explains why TCA is so difficult to control.

Bed bugs

Are even entomologists getting weary of bed bugs? Maybe. Bed bugs were the subject of 31 papers and posters this year, down from last year's 46 (and a record 56 papers in 2011).  Most of this year's talks were given during a symposium called Advances in the Biology and Management of Modern Bed Bugs. The session featured authors of a new book of the same name to come out in 2018.  If you dig scholarly work on bed bugs, this might be a nice addition to your library--if you can afford it (listed at $200, not unusual for academic books). According to the publisher, it will be the first comprehensive academic review of bed bugs since 1966. NPMA attendees will recognize the names of many U.S. authors like Rick Cooper, Changlu Wang, Dini Miller, and Jim Fredericks.  And there will be a number of international authors as well.

I'm saving up for my copy, but the title got me wondering, "What's a modern bed bug?" So I asked Dini Miller, of Virginia Tech and one of the editors of the book.  She replied that "these are not your grandmother's bed bugs." These are the "incredibly resistant" bed bugs that have made their comeback over the past 20 years. Modern bed bugs have thicker cuticles to resist insecticide penetration, tougher nerves, and better enzymes to detoxify these insecticides. Given that the tropical and the common species of bed bug both have developed these characters, the book theorizes that malaria control programs in Africa, where both species live together and are regularly exposed to DDT and pyrethroids, may have been the breeding ground for these new "super bugs."  Anyway, there is obviously a need for an updated book on on bed bugs.

Research Highlights

Today's bed bugs are more difficult to kill with insecticides. All
the more reason to use a variety of control tactics.

The Highlights of Urban Entomology session is one of my favorites for catching up on papers I may not have had time to read this year. This year's presenter was Chow-Yang Lee, Professor at the Universiti Sains Malaysia, and soon to be with the University of California at Riverside. He and colleagues recently reviewed the literature and found that resistance to chlorfenapyr (Phantom) is "brewing" among modern bed bug populations. Also, bed bugs tested recently from Cincinnati and Michigan show moderate to high resistance to neonicotinoids used in products like Temprid and Transport, Mikron and Tandem. If you had hope that baits might be the answer, a study by Yvonne Matos and coauthors found that secondary kill of bed bugs is much lower than for cockroaches. Even if a suitable way to bait for bed bugs was found, current evidence suggests that baits would likely not be as effective as cockroach baits.

Finding better formulations is a productive field for improving pest control. Vander Meer and Milne reported improved control of fire ants with a waterproof formulation of Distance fire ant bait. Made from dried distillers' grain with solubles and shrimp shells, it outperformed standard corn grit baits. This formulation will likely be more effective as a control for red imported fire ant and little fire ants, especially in wetter locales.

Literature reviews are papers that synthesize lots of scattered research into something that makes sense of the topic. A good literature review is invaluable, especially if you're not an expert. So, I was glad to learn of a new (and free via this link) literature review on fleas, recently completed by the venerable urban entomologist, Mike Rust. Rust looked at some of the more recent advancements in flea borne diseases, new control products, and resistance to insecticides. Contrary to what you might hear from pet owners, there is little evidence that fleas have developed resistance to the very powerful on-animal treatments like fipronil, imidacloprid or lufenuron. On the other hand, pyrethroid resistance by fleas is becoming more widespread. While on-animal treatments solve most problems, pyrethroid resistance poses a dilemma for PMPs needing to treat flea infestations that arise from non-pets, such as feral animals (in a crawl space, say, or in backyards). Not many non-pyrethroid broadcast spray alternatives are available for this task.

Certification

Lastly, I had the opportunity to attend a committee meeting on the ACE (Associate Certified Entomologist) program. This is a program for anyone in pest control who wishes to identify themselves as a certified entomologist. Since last year, Willet Hossfeld has taken over administrative duties for the Certification program.  He reported that there are currently 1025 active ACEs nationwide, with 267 in the application process. If you ever have a question about the certification application, he's the one to contact.

The main topic of discussion by the support committee this year concerned the difficulty of the certification exam (40% pass rate on first try), and how that has discouraged many highly qualified folks from taking it. Several at the meeting noted how useful the study guide that I and Richard Levine co-authored a few years ago, has been.  But there still seems to be a need for group prep classes to better prepare ACE candidates for the exam.  The committee took steps to begin updating the practice exam for those preparing for the test, and discussed how to make more prep classes available.  A prep class PowerPoint set has long been available to anyone who wants to conduct a prep class. This PowerPoint set will be revised and updated in 2018.  Any BCE or ACE who wants to sponsor a prep class, should contact Willet at ESA and he can tell you how it's done and how to get a copy of the prep materials.

You're Invited

Pest management professionals also attend these national meetings. If you haven't yet attended, I encourage you to give it a try (the next two meetings are in Vancouver BC in 2018, and St. Louis MO in 2019). The meeting is a great time to make new friends and professional contacts; and while it's not all pest management oriented, there are always good urban entomology sessions featuring cutting edge research. If you decide to attend, don't be shy--introduce yourself to speakers and others in hallways. Consider attending the Certification Board meetings; visitors are welcome. And bring a few extra bucks for a t-shirt or pet tarantula. Your coworkers will look at you strangely, and you'll know what it's like to call yourself an entomologist.

Comparing dusts for bed bug control

For several years PMPs have known that dusts can be useful tools in the management of bed bugs, but a new paper in the Journal of Economic Entomology by Narinderpal Singh and colleagues at Rutgers University shows just how powerful they can be.

Singh et al. used four different lab assays and two strains of bed bugs to probe the efficacy of eight insecticide dusts.  Each assay showed a different aspect of how these dusts perform.  Together, I think, they do a pretty good job of evaluating how you can reasonably expect these products to perform in the real world.

Four experimental assays used to study the toxicity of
various dusts and predict their effectiveness in the field.
Clockwise from upper left (1) brief exposure assay, (2)
choice assay, (3) assay where CimeXa-treated bugs are
allowed to mingle with untreated bugs, and (4) continual
exposure assay with treated paper . (Singh et al. 2015,
J. Econ. Entomol.)

One of the problems with doing lab assays is that they can be highly unrealistic.  Sure, you can put an insect on a treated surface and watch them until they die (a continuous exposure assay).  Certainly this kind of assay can tell you whether there is potential for a product to work; but in a customer's home do your bed bugs have nothing better to do but sit on the insecticides you put out?  Probably not.

More often than not in the real world, insects run quickly across an insecticide barrier and then spend most of their time resting on untreated surfaces. Insecticide exposure may be only a matter of seconds. At other times, insects that move back to a treated harborage may be able to sense when they are on insecticide residues.  They may then choose to move to a clean spot that has not been sprayed or dusted (a sign of repellency).  Continuous exposure assays may overestimate the effectiveness of insecticide applications, especially when applications do not reach key harborage areas, or when residues are repellent to the pest.

On the flip side, insects may inadvertently pick up insecticide residue from a treated surface and carry that insecticide on their cuticle back to a harborage area. When this occurs they may transfer it via contact to other bed bugs clustered in the same harborage.  Failure to account for this in lab assays might end up underestimating the effectiveness of your treatment.  

Singh and colleagues tried to account for all of these possibilities in their research. One assay required the bugs to sit on treated paper for the length of the study.  A second assay had the bed bugs walk across a treated one-inch barrier.  And a third test gave the bugs the choice to visit and rest on either dust-treated or untreated surfaces.

Bed bug dusts included in the trial were Tempo, DeltaDust, Cynoff, Pyganic, EcoPCO D.X, Alpine, MotherEarth, and CimeXa. 

As you might expect, all products killed bed bugs when they sat continuously on the treated surfaces. After five days there was 100% mortality for all bed bugs in the treated dishes. When bed bugs were allowed to choose freely to rest on either treated and untreated surfaces, CimeXa and Tempo gave 80-95% control after one day; however after 10 days MotherEarth (diatomaceous earth) and Cynoff were close behind.  

The clear champion of the toughest test, the brief exposure test, was CimeXa Dust. CimeXa provided 95-100% mortality (at 1 and 10 days after exposure) to bed bugs crossing a one inch barrier of the dust.  Tempo was the next most effective product in the brief exposure trial, providing 40-60% mortality against the two bed bug strains. This ability to kill bed bugs with very short contact can be a game changer. It suggests that CimeXa may be capable of providing decent barrier protection on bed and furniture legs, in dressers or even along door thresholds (though unprotected deposits will likely be quickly rubbed or swept away). 

Singh and his team then went on to see whether CimeXa might also have the ability to transfer from exposed to unexposed bed bugs. It did. Clean bed bugs, that had not been previously exposed to CimeXa, when placed with CimeXa-treated bugs also had significantly higher (80-100%) mortality after 10 days compared to untreated controls.

Singh's work backs up previous work done by Mike Potter's lab in Kentucky.  Potter's group found that CimeXa was more effective than liquid Temprid residues against resistant bed bug strains in continuous exposure assays. He also found that as a stand alone treatment in infested apartments it provided rapid and marked control, superior to diatomaceous earth, and similar to that provided by the top liquid insecticide sprays. 

What these studies tell me is that insecticide dusts should definitely be part of your bed bug control program, especially in accounts with insecticide resistant bed bugs.  Silica aerogel, the active ingredient in CimeXa, performed better than the other commonly used desiccant (MotherEarth, i.e., diatomaceous earth), and even out performed the other pyrethroid dusts.  It should be noted, however, in settings where harborages can be fully dusted, these other products may still provide good control. And laboratory tests cannot fully duplicate what happens in the field--your real world accounts.

But my real reason to single out this study is that it provides a true low-risk option for bed bug control.  Because the mode of action of desiccant dusts is based on abrading the cuticle of the insect, and not on any mechanism that would potentially affect human health, it's a no-brainer to make these products a mainstay of your dust arsenal.  Used inside furniture, behind drawers and baseboards, in cracks and crevices of bed frames, these products make excellent, safe to use, treatments. Even if heat treatment is your tactic of choice, insecticide dusts can provide a long-term supplemental treatment to kill any bed bugs that might re-infest an apartment, hotel room or other bed room.

If dusts are not an important part of your chemical or heat treatment protocols, you may be missing out on a relatively economical, effective and safe option to improve your success rate against these adaptable and tough-to-kill pests.  

Highlights of NCUE

Albuquerque, NM was a beautiful (and tasty)
location for this year's NCUE meeting.

One of the first professional meetings I attended as a newly minted PhD entomologist was the National Conference of Urban Entomology. Held that year in College Park, Maryland, the meeting was a revelation.  Finally, I thought to myself, a gathering of people who understand what I do for a living--like a Cheers bar for entomologists!

We've all been to parties and been asked what we do for a living. Answer that you're "an entomologist who specializes in structural insect pests", and if you're lucky you'll get a wan smile. Rarely does anyone get it. Not so at the National Conference of Urban Entomology. The NCUE is a gathering of very friendly, slightly nerdy, science-oriented people who love to talk about urban insects and pest control.  No one in this group needs bother with common names when discussing Periplaneta americana, or Coptotermes formosanus. Talks like "Gut bacteria mediate aggregation in the German cockroach" are guaranteed to draw a crowd.

This year's NCUE meeting was held in Albuquerque, NM, and it did not disappoint.  Besides a short, but packed agenda of buggy stuff, Albuquerque was a wonderful place to meet.  Not a whiff of Breaking Bad drug labs, but lots of clear skies, mountain and desert views, and great New Mexican cuisine. (Oh, and The Donald was even in town one night!)

To give you an idea about what all of us bug scientists talked about in the sessions and hallways this week, here are some of my notes to self:

• Pest exclusion was the dominant topic for one session and was revisited throughout the meeting.  Imagine if homes and offices could be designed to keep pests out, or at least make them uncomfortable.  Dr. Jody Gangloff-Kaufman from the New York State IPM Program talked about two relatively new working groups dedicated to promoting better building standards to resist pests.  They call their project SCOPE (Scientific Coalition of Pest Exclusion), and the two groups focus on residential and commercial buildings, respectively.  The group has been meeting for approximately 2 years and has about 120 members.  Goals are to assemble a database of literature that supports pest exclusion (PE) concepts, and to provide checklists for builders and architects to promote better PE. A bit of controversy arose when a session speaker suggested that perhaps the typical pest control business model would not willingly embrace pest-resistant buildings. A PMP participant objected saying that offering pest proofing was an important part of their business model and how their company remained competitive.
• Dr. Chris Geiger, with the City of San Francisco, spoke about how IPM and PE principles have influenced the LEED (Leadership in Energy and Environmental Design) program. LEED remains one of the most influential and successful certification programs ever, contributing $80.6 billion to GDP between 2011-2014 and changing the way architects design modern buildings. Dr. Geiger noted that 59% of LEED-for-existing-buildings applications take advantage of points for having an IPM program in place.
       Although LEED recognizes the importance of IPM to environmentally sound construction and maintenance of buildings, it has not provided strong leadership on pest exclusion. Consequently, in 2013 Geiger led a group to produce a guidance document for architects and builders to provide specific examples of how to make buildings more pest resistant.  These guidelines are being put to work in some major public housing renovations in San Francisco, and have been offered to builders as a standard to reference when trying to achieve IPM points in LEED projects.
       Dr. Geiger hopes to update these guidelines this year, and is actively seeking experts in pest control, engineering, entomology, and architecture to be a part of the process.  If you are interested in joining his group, go to this web form to add yourself to the list of participants.
• Dr. Tim Husen with Rollins Corporation suggested that PMPs needing fast access to a listing of low toxicity products acceptable to LEED certifiers can use a mobile phone app called PestSmart, available through the Pesticide Research Institute. I found and downloaded this free app quickly on the App Store for my iPhone.  The listing is based on criteria used by the City of San Francisco in their (now extinct) Tier III list of low toxicity pesticides.  This famed list is no longer supported or updated by the City of SF, but is still sometimes referenced by architects, especially under the now dated, V3 (2009) LEED credits.  Keep in mind that the PestSmart app provides an assessment of likely toxicity, but does not take into account risk of exposure, an important component of hazard (toxicity X exposure = hazard).  
• Famed "rodentologist," Dr. Bobby Corrigan, also spoke on rat exclusion, and provided a case history from the National Park Service's African Burial Ground Monument.  A highly sensitive, historically significant site in New York City, the property was heavily rodent infested prior to Corrigan's consultation.  Xcluder Geo Mesh was installed under sod at the site, and burrows were gassed with dry ice (2 lbs per burrow system) to successfully rid the property of these "diabolically clever" pests, as Corrigan described them. Though initially more expensive, Corrigan believes the use of CO2 and advanced mesh barriers like this could be very useful for eradicating rodents from sensitive locations.
• Not surprisingly, mosquitoes were a hot topic of discussion this year. PMPs are beginning to shift their company business models to include mosquito control. Orkin's Dr. Ron Harrison noted that mosquitoes are his company's number 1 annual service offering. Rick Bell, with Arrow Exterminating, reported that his company's mosquito revenue has gone from $39,000 in 2004 to $6.5 million in 2015, all with little reliance on automated backyard mosquito misting systems.  He noted that Arrow's mosquito control customers are among their most loyal, with a 92% annual retention rate. 
• Dr. Joe Barile of Bayer Environmental Science cautioned the industry about how mosquito control is marketed. He recommended use of the term "nuisance abatement" rather than any language that implied disease elimination or protection from mosquito borne disease.
• Dr. Grayson Brown from the University of Kentucky summarized some of the latest promising technologies for residential mosquito control. He reported that the Innovative Vector Control Consortium (IVCC), a group founded over 10 years ago to seek solutions to mosquito borne disease, is currently evaluating 9 new classes of active ingredients for vector control. If even a few of these insecticides prove safe and effective, it could revolutionize adult mosquito control. He also noted that essential oils are also receiving more study as insecticides, repellents and excitatory agents to enhance the effectiveness of other products.
• Although it appears that most pest control companies rely largely on barrier sprays as a core of their mosquito control programs, pollinator and beneficial insect concerns are an issue. Consequently, there is much interest in alternatives to backyard sprays for mosquito control. Among the promising alternatives, according to Brown, are autocidal gravid oviposition (AGO) traps.  These are artificial breeding sites for Aedes mosquitoes which trap, kill, contaminate or sterilize any female mosquito lured in to lay eggs.  In one study in Puerto Rico, 3-4 large AGO sticky traps per yard were sufficient to reduce Aedes mosquito populations 53-70% and prevented mosquito outbreaks following rain in 81% of homes. 
• Pyriproxyfen, the insect growth regulator in Archer® and Nygard® insecticides, is also being tested as an active ingredient in some autocidal traps.  Research suggests that besides killing their mosquito offspring before they emerge from treated water or cups, pyriproxyfen residues in these traps transfer via the mosquito herself to other breeding sites through a process called auto-dissemination. This is one of the coolest and most selective mosquito controls I've heard of.  If proven in the field, a PMP or homeowner, could put a few gravid traps out in the yard for minimal cost and get season long mosquito suppression with no risk to bees, butterflies or other beneficial insects.  In combination with sprays and other control methods, it might be possible to achieve a high level of control and reclaim mosquito infested backyards with minimal harm to good bugs. Currently few lethal ovitraps are commercially available; but watch for new products to enter the market soon.
• No gathering of urban entomologists would be complete without a few papers on bed bugs. Though the number of bed bug papers was down this year, those presented were oriented towards the practical.  Three papers came from Virginia Tech.  Dr. Dini Miller presented on bed bug vacuums. She found that all the battery powered vacuums she tested (several Black and Decker, and Dyson models) were surprisingly effective at removing adults, nymphs, exuviae and eggs. Besides offering a cleaner and more allergen free environment, it is notable that vacuums remove the exuvia (cast skins) of bed bugs.  This is important for control, she noted, as cast skins may be used by bed bug nymphs as a refuge from sprays.  She also recommended using disposable, knee high, nylon stockings over the mouth of your vacuum (which she colorfully called "condoms for your vacuum") to isolate your catches and reduce the risk of bringing bed bugs back to the office.
• Katlyn Amos, graduate student at VT, tested two multi-action insecticides against pyrethroid resistant bed bugs.  Both Tandem and Crossfire, a new product from MGK, performed well against these resistant bugs. 
• Molly Stedfast reported on mattress encasements for bed bugs.  One of her most important findings was that not all bed bug encasements were bite-proof. After stretching encasement fabric over the mouths of glass jars filled with bed bugs, and applying the fabric-covered mouths to the arms and legs of volunteers, many of the bed bugs were able to successfully feed. But as Stedfast noted, bite resistance is not an issue for box springs.  Nor may it be that critical for bed mattresses either.  Bed bug mouthparts are only about 1 mm long, so once covered with a mattress protector and sheet, the average sleeper should be well protected from any bed bugs trapped in a tight encasement.  Tight zippers and rip resistance are probably more important features when selecting an encasement. 
• In the category of really-interesting-science-that-may-not-have-an-immediate-application, Dr. Rachel Adams, University of California-Berkeley, talked about the microbial diversity of homes.  The ability of science now to take DNA swabs and identify 40 microbes from one's forehead has rapidly progressed from my college microbiology class where "cutting edge" meant plating out and isolating a few microbe colonies on Petri dishes. This new technology means we can now isolate hundreds or thousands of fungi and bacterial DNA from the average home. The challenge we have today is understanding what these microbes are doing.  Are they reproducing, or just there because they floated in from outdoors?  And what are their human health impacts, if any? We know that microbes can positively or negatively affect our health, allergies and possibly ability to ward off disease.  One example Dr. Adams gave was the so-called 'farm effect', where children who grow up exposed to bacteria associated with cows and manure have asthma rates as much as 4X lower than urban-raised children. Insects may play a role in delivery of some of these microbes, good or bad, into homes.
• Finally,  Dr. Coby Schal, one of the most interesting and creative urban entomology researchers in the country today, spoke about the gut bacteria in German cockroaches (Blatella germanica to us entomologists!). His research has shown that it may be bacteria that are responsible for much of cockroach aggregation behavior.  Cockroaches with their full gut bacterial complement grew up faster, reproduced faster, found mates faster, and were more efficient foragers compared to cockroaches without their gut microbes.  In addition, cockroaches were more attracted to the poop of other cockroaches with buggy guts, suggesting that these microbes might hold the key to developing a better cockroach attractant for trapping and control purposes. And you might be surprised how much cockroach feces humans are exposed to. A colony of 1,000 German cockroaches (a moderate infestation in some restaurants and apartments) produces an estimated 5 grams of feces per night, or nearly 2 Kg (4 lbs) of feces a year. These same feces contain 7.5 million units of Bla-g antigens, which can cause allergies or asthma in humans in amounts as little as 8 units.

Now you know what urban entomologists talk about when they get together. The subject matter may be boring, humorous or even distasteful to the average person; but be thankful that someone is interested in this stuff.  As for me, I'm glad there's at least one place where everyone knows my name. Cheers!

Managing bed bugs in multifamily housing--insights from ESA

The Minneapolis, MN Convention Center hosted this year's
annual conference of the Entomological Society of America

It's been almost 15 years since bed bugs started as a hot symposium topic at the annual conference of the Entomological Society of America. And following this year's meeting in Minneapolis, it seems like solutions are still elusive, especially when it comes to multifamily housing.

As usual for me during these marathon meetings, I attended as many talks about bed bugs as I could.  But this year I was especially attracted to discussions about bed bug management in multifamily housing, a.k.a. apartment complexes.  There were several interesting papers related to the topic, but three of them seemed to do an exceptional job of illuminating the issue and possible solutions.

Virginia Tech and Apartment Managers

I know of no one who exhibits more passion about bed bug management in multifamily housing than Dini Miller of Virginia Tech University.  In fact, to keep up with the overwhelming education demands in this area, her group recently established a Bed Bug and Urban Pest Information Center to better educate Virginians (and especially apartment managers) about bed bug control.

According to Miller, a big part of the reason that bed bugs are such a problem in apartment complexes is that they are not just a pest problem. Bed bugs are also a social problem with a unique human dimension. In her ESA talk Miller observed that in her experience the worst bed bug infestations seem to occur with individuals who have problems that are much worse than bed bugs (e.g., health issues, finances, safety and security).  Such tenants, for a variety of reasons, are less likely to complain to management about bed bugs.  On the other hand, the most vocal complaints often come from those with relatively small-scale bed bug problems. Therefore, when an apartment complex bed bug control program is primarily complaint-driven, the program is doomed to miss what should be the highest priority units.

Miller believes that good apartment management is key to an effective bed bug program. To be successful, she argues, (1) managers must be committed to solving the problem, (2) the response needs to be proportionate to the problem (less money and time on small infestations and more effort on finding a eliminating heavy infestations), (3) apartment preparation requirements must be reasonable (with assistance provided for the elderly), and (4) managers must be better informed and involved with the pest control company in the IPM process.

For managers who don't feel that bed bugs are that big an issue, Miller notes that one 4,000 unit complex she works with spends $500,000 annually on bed bug control.  And liability is also a big issue. In Iowa in 2014, residents of a public housing complex successfully sued management for $2.45 million for an uncontrolled bed bug infestation.

Rutgers and Bed Bug IPM

Climbup interceptor cups were effective at detecting bed bug
infestations 95% of the time in the Cooper study. Pitfall traps
like the Climbup detect 3X as many low level infestations
than would otherwise be reported by tenants.  

Another leading bed bug researcher, Changlu Wang from Rutgers University, offered his own perspective on reasons for the ongoing bed bug crisis in multifamily housing.  He said that the biggest challenges come from (1) heavy infestations associated with clutter, (2) widespread resistance to insecticides among bed bugs, (3) the small size and difficulty in finding bed bugs (thus determining whether an infestation is eliminated), and (4) the need for cooperation from residents.

As background, Wang and his laboratory have undertaken some ambitious field trials in the past few years.  I say ambitious because it is extraordinarily difficult to do large scale control studies in apartments.  Not only do researchers have to work with the same unpredictable clients you work with daily, they also have to get approval from a group called the Institutional Review Board (IRB).  Each University has an IRB that oversees any research done with humans or animals, ensuring that the research is done ethically and without harm to its subjects. Getting through the process requires lots of paperwork and is enough to make you crazy.

In a study just published by Wang's recent Ph.D. student, Rick Cooper, an IPM program was pilot tested at a four building complex with 358 units housing elderly and disabled residents.  The IPM program consisted of resident education, initial monitoring with ClimbUp® interceptors to determine which units were infested, encasements, vacuuming, steam, laundering assistance, and insecticide applications with diatomaceous earth and chlorfenapyr.  Units with less than 5 bed bugs received non-chemical treatment only.  Units that continued to be infested with more than 5 bed bugs after the first treatment received spot treatments with Transport GHP.  Followup treatments in all originally infested units were continued every two weeks until no bed bugs were captured in interceptors, seen, or reported by the residents for three consecutive visits.

Relationship between the initial number of bed bugs in a treated
apartment and the number of treatment visits needed to eliminate
the problem.  An initial infestation of 100 bed bugs required  ca.
10 visits to verify elimination. From Cooper et al. Jan. 2015.
Pest Management Sci.

Cooper's experiment is the first research to document the success of a bed bug IPM protocol in an entire apartment complex. Key findings of the study were:

• Management was aware of only 29% of the infestations before Climbup interceptors were used.
• It took an average of 2 to 4 minutes (they got faster throughout the study) to install approximately 10 interceptors per apartment.
• It took less than 4 minutes to inspect Climbups compared to over 15 minutes to conduct a visual inspection of an apartment.
• Because of the difficulty in detecting low levels of bed bugs, the authors defined "elimination" as three consecutive visits with no live bed bugs detected by Climbup counts, visual inspections and resident reports. The authors considered the stringent elimination protocol an essential part of the IPM program.
• Researchers estimated the overall infestation rate of the apartment complex was reduced from 15% to 2.8% at 6-months and to 2.2% at 12-months, an 85% improvement. 
• In infested apartments the mean number of bed bugs trapped was reduced by 96% and 98% after 6- and 12-months, respectively. 
• Heavily infested apartments at the beginning of the study required the most visits to achieve control, hence costing the complex more. 
• 62% of residents with bed bugs were not aware that they had bed bugs, including one oblivious resident whose apartment had over 4,000 bed bugs, many of which were openly crawling on the bed during inspection.
• 76% of residents who thought their bed bug problem was solved through treatment still had bed bugs detectable with Climbups, supporting the idea that customer satisfaction should not be the sole criterion for determining when treatments can be stopped.
• Average labor and chemical costs for the 12 month treatment for 66 apartments was $456 per apartment, a figure in line with other programs and which the authors believe can be reduced in subsequent years of a contract.

A full copy of Cooper's excellent study can be accessed here.

University of California Survey

In contrast to what ought to be done about bed bugs, Andrew Sutherland of the University of California's Statewide IPM Program, reported on what is being done for bed bugs in the western region of the U.S.  He surveyed 114 PMPs in California and other western states and provided some useful insights into current industry bed bug practices.  His study confirmed Miller's observation that compared to hotels and single-family homes, multifamily housing was rated by respondents as having the worst infestations, the most-difficult to control infestations, and being the most often treated kind of account.  When asked about monitoring methods used for bed bugs, 98% of respondents employed visual inspections "most of the time".  Pitfall traps were used at least once by about 75% of respondents; but only 20% said they used this tool "most of the time".  About 40% of respondents used canine detection at least once.  Surprisingly, glue boards had been used by about 75% of respondents, at about the same frequency as the far superior pitfall traps.  

Regarding control methods, insecticides were used "most of the time" by 94% of respondents. Desiccants were used to some extent by 85% of respondents, but only by 57% "most of the time". Encasements were used "most of the time" by 50% of respondents.  And 53% of respondents never used volumetric heat treatment--not surprising given the relatively high initial cost of the equipment. 

Among liquid sprays, the insecticides used "most often" by respondents were neonicotinoid+pyrethroid combination products (53%), followed by chlorfenapyr (20%), followed by pyrethroids (17%). Among dusts, pyrethrins (surprise to me) were most commonly used, and least used were the highly promising silica aerogels.  A copy of the PMP portion of his survey results has been published in PCT magazine.

In addition to PMPs, Sutherland surveyed 167 housing management professionals, and the results were also revealing. Eighty-seven percent of respondents said that bed bug service in their facilities was complaint-based, just what the Rutger's and Virginia Tech entomologists said doesn't work. Also, 72% of respondents make their tenants responsible for preparing for a bed bug treatment--not a good idea for elderly and disabled who are often unable to perform prep tasks.  And 69% of respondents said they used a bed bug addendum as part of their lease agreement.  Such addenda generally put responsibility for bed bugs back on the tenant, discouraging many from reporting infestations when they are small and easily treated. These latter results, especially, suggest that the pest control industry, and we in Extension, have some work to do.

These three talks for me illustrated why bed bug management, especially in multifamily housing, remains a challenge.  Within the industry better IPM protocols are needed, especially protocols that rely on proactive monitoring and early intervention, sanitation, physical and mechanical controls, and conservative, targeted use of carefully chosen pesticides. I think we also need to take a closer look at desiccant dusts, perhaps an underused, low toxicity tool in the bed bug tool kit.  Within the apartment industry, managers and tenants need to be educated about the importance of monitoring-based protocols, minimum prep models, and reversing the "blame the tenant" mindset. All research shows that the sooner a bed bug infestation is detected, the better the prognosis for a quick and less-costly response.

Given that approximately 26 million households reside in multifamily rental housing (2014 data from National Multifamily Housing Council), there is hardly any pest control issue in the U.S. today that affects more people in a more personal way. The way that pest management and multifamily housing businesses respond to the challenges of bed bugs in the coming years will say a lot about the character of these two industries.

Bed Bug Academy offers surprises

I wasn't sure what to expect when I got invited to attend the Bed Bug Academy event sponsored last month by the Texas Pest Control Association. I knew that I knew something about the subject of bed bugs, but I also knew there was a lot more that I needed to know. Boy was I right on the last part.

In case you haven't been paying attention, over the past year or so bed bugs have generated an incredible new business in products that offer control as well as conferences on how to build your bed bug business. The North American Bed Bug Summit offered last year and again next month in Chicago, IL is perhaps the biggest venue.

The experience and manpower behind these conferences, including the smaller Bed Bug Academy here in Texas, is Bed Bug Central.  Brainchild of Phil and Richard Cooper, of New Jersey's Cooper Pest Solutions, Bed Bug Central has established itself as the premier training provider for pest control companies wanting to enter the bed bug arena.

After attending the summit I've concluded that the Cooper brothers do a pretty good job of presenting information in an understandable and comprehensive way.  No one could criticize them of being superficial in their coverage either. Their main instructor, Jeff White, is obviously well experienced and a good communicator.  The result was a stimulating and helpful boot camp for anyone wanting to begin, or get better at, bed bug treatments.

I have to admit that I’ve yet to personally treat an apartment or hotel room for bed bugs. I have, however, attended a number of presentations by bed bug researchers and PMPs at Entomological Society of America meetings where the process has been described. I’ve always come away amazed at the amount of work these folks say needs to be done to thoroughly treat an apartment or room.

Typical research-based recommendations for treating a room include removing all furniture and belongings, treating every square inch of room and closet, and thoroughly inspecting, treating and replacing every furniture piece before returning to its place. In addition, the standard scorched earth protocol requires extensive preparation on the part of the tenant or homeowner to clean up and bag most of their personal belongings. Just describing the process makes me tired.

The BBC approach evolved from the real world where tenant cooperation and follow up is unreliable, and technician time costs money. Consequently the stripped down approach taught in these classes is different from what I expected to hear. This is not saying that the BBC system is not a lot of labor--it is.  But the BBC approach, I think, is more sustainable and practical for most accounts.

According to White, the biggest challenge in bed bug control is to make bed bug control more affordable. So rather than charge all accounts a higher rate based on worse-case scenarios, they hedge their bets with a careful assessment and cost estimate for each account. Standard service starts with a two-technician, 20-minute inspection to evaluate the numbers of bed bugs and the complexity of the account. All sites are then classified as low (less than 20 live bed bugs), moderate (21-100 live bed bugs) or high; and treatment complexity is assigned on standard room contents plus additional costs for more cluttered or complex living situations.

Service of units with low level infestations is the most stripped down.  It includes a thorough inspection and treatment of the bed and all furniture within two feet of the bed. Unless other furniture or closets are seen to be infested, they receive only minimal treatment with residual sprays. Other rooms of the house are only given thorough inspections and treatment if other people are known, or suspected, to be living there. Wall junctions and baseboards are treated, but not ceilings unless bed bugs are observed. Steaming, which is a slow, but essential part of the service, typically takes only about five to ten minutes per apartment with this targeted treatment approach. Vacuuming is used to remove live bed bugs encountered during the inspection.  A two foot area is steamed around any spots where live bed bugs or their droppings are found.  Only in high- or moderately-infested accounts does the company begin to come close to the "scorched earth" strategy.

Perhaps the most surprising difference in the BBC approach is their Limited Prep model. The idea behind limited prep is that when tenants scramble to clean things up before the treatment date they inevitably scatter bed bugs into sites where they would not normally be found, such as closets or bookshelves. By leaving things in place, bed bugs are more easily found and treated or vacuumed. Using this model the tenants are asked only to the clean the unit enough to allow technicians access. Items under and around the bed are requested to be left in place. If the technicians encounter anything that needs to be laundered or emptied, they leave the items bagged with an instruction sheet on top telling the tenant what to do for the next service.

Evidence for the success of the limited prep and tiered treatment approach is Bed Bug Central’s customer promises. Moderate infestations are charged on the assumption of have three to four services. If bed bugs are still a problem after four services, the client is not charged. The company also boldly offers a five-month "No bugs--no bites" guarantee for most accounts.

Refreshingly, the focus of the BBC approach was not on which insecticides work best. All current bed bug insecticides have their limitations, we know. According to Dr. Dini Miller, the best we can expect with the current arsenal of insecticides is contact kill. In other words, “you only get what you hit.” None of the pyrethroid insecticides are consistently providing residual kill--that is, once they have dried. This means that good application skills are absolutely essential. Heat treatments, barriers, traps, steam, cold, and vacuuming all should play a part in an effective bed bug control plan.

Of course the Academy covered much more than what I can in this short review. If you have a chance to attend one of these programs, I think you’ll find it worth your time. As to the inevitable question lurking in the backs of everyone’s mind, “Can anything good come out of New Jersey?” In this case I think the answer is YES.

The life span of bed bugs

One of the most often cited "facts" about bed bugs is that they can live over a year without a blood meal. But is it true?  That's what Andrea Polanco and colleagues at Virginia Tech set out to investigate in their recently published article in the open-access journal insects (open access means articles are free and open to the public).  Their work, as well as a careful reading of the original source of the one-year-survival statistic, suggests that bed bugs (at least starved bed bugs) may not be as long-lived as the legend says.

One of the sources of the original research suggesting extremely long lives for starved bed bugs came from a paper by Japanese scientist named Omori in the early 1940s.  This paper has been cited numerous times, principally because of republication of the data in Usinger's (1966) book on bed bugs, which has been a basic reference for researchers since the bed bug resurgence. If you check the original data from Omori carefully, you will see that adult bed bugs live longest (15 months) at low temperatures (50 degrees F). At more realistic indoor temperatures (65 to 80 degrees F--Omori didn't look at in-between temperatures) the average survivorship of unfed adults was about 160 to 40 days, respectively. Other, less carefully conducted research prior to 1950 suggests maximum bed bug lifespans of 5 to 19 months.

Polanco's work was conducted at a constant 78 degrees F and 69% RH.  Their results for insecticide susceptible strains are not that far from Omori's estimates of 40 days at 81 degrees F.  But the most interesting conclusion of Polanco's work is that insecticide resistant strains of bed bugs (which are increasingly common worldwide) live for a significantly shorter time when starved (39 to 76 days) than their insecticide-susceptible counterparts (73 to 106 days).  The longest life span observed in Polanco's research was an insecticide-susceptible 5th instar nymph, which lived 143 days without a blood meal. Field strains of resistant bed bugs did not live longer than 80 days. These data are still a far cry from the 12 to 15 month longevity figure often cited to amaze people about bed bug resiliency.

One of the most interesting things about Polanco's team's work is the demonstration that insecticide-resistance can make an organism less fit in some ways.  This has been seen in other insects (e.g., cotton bollworm in cotton) when insecticide pressure is removed and insect populations revert (through natural selection) back to susceptible forms--presumably because the susceptible forms are overall more fit for survival.

So when talking to your customers about bed bugs, it's time to drop the 12 month statistic.  It's more realistic to say that today's bed bugs can live 3 to 5 months without a blood meal. 

Don't get me wrong.  Two to four months without food is still impressive.  But bed bugs are not immortal, and like all pests they too have their limits of endurance.