Monday, March 19, 2018

Rat Ice: It's Complicated

The extensive burrow networks of Norway
rats in city parks have been hard to treat
safely, until now. (Photo courtesy of Matt Frye)
New York is planning to rely more on dry ice as a safer and effective treatment for rat colonies living in city parks.  But the logistics of labeling and marketing frozen carbon dioxide as a rodent control product have proved to be challenging.

Toxicity of carbon dioxide to rats is nothing new. When placed into a rodent hole and covered with soil, pelleted dry ice (frozen CO2) slowly evaporates filling the burrow with the gas and displacing the oxygen. Such treatments are low-in-risk for humans, leave no toxic residues, and pose no risk of secondary wildlife or pet poisoning.

Until now, the only barrier to its use was that dry ice was not registered as a pesticide and technically could not be used in commercial pest control. But last year, with the help of the National Pest Management Association, the rodent control product manufacturer, Bell Laboratoriesagreed to work with the U.S. EPA to develop a label for dry ice pellets. The EPA, in turn, moved quickly last June to support the new "Rat Ice" label.

Unfortunately, as of today, Rat Ice is not available through any pest control supply distributor.  Of course, different forms of dry ice are readily available through many gas suppliers, liquor stores and grocery stores. But forget using over-the-counter dry ice. It's not legal.

Rat Ice will be a proprietary product sold as a conventional pesticide and distributed through normal supply channels along with a label.  For example, if your local pesticide distributor warehouse agrees to serve as a supplier, they will purchase and store the ice in special freezers and sell them just like any other pesticide.

According to Bell Laboratories technical rep, Scott Smith, Rat Ice will be sold in 1/2 and 3/4 inch pellets. Purchasers will be issued a label to place on their transport box, and will take from the distributor to the job site.

"Working with a perishable product like dry ice is complicated," Smith said. "We have retained a national distributor to transport the ice to local distributors, and plans are looking good on paper, but we fully anticipate some "aha!" moments ahead."

Challenges for Bell include enlisting distributors willing to handle inventory that literally evaporates if not sold soon enough.  Also, there's a question about whether PMPs will buy a product that is similar to one they could purchase at their corner grocery store. And how will pest control companies located far from big cities and big distributors get the product?

Smith is confident that a good system will be in place by the time Rat Ice hits the market. But it will take time.  Expect several months before product roll-out takes place, he said.

As someone who has struggled to find a convenient-to-use version of dry ice for research, I like the idea of the pelleted formulation. It will make application to burrows easier and safer.  And our industry has generally played well by FIFRA rules long enough, I believe the issue of "product swapping" will be minimal.

Rat Ice is no silver bullet, but it may revolutionize the way many PMPs and city health departments do rodent control. In tests conducted in 2016 by the City of New York, dry ice pellets inserted into rodent burrows reduced the number of active rat burrows in one park from 60 to just two. Another city park saw a reduction of 368 burrows down to 20. Impressive.

Cost for Rat Ice has not been determined, but the quick kill and low risk associated with this product should make it a popular option, especially for anyone who does a lot of Norway rat control.

If this concept works, and I hope it does, the PMP tool box may have to expand to include high-end coolers to keep your CO2 in solid form.  Just be ready to explain to your boss why you keep a Yeti® in your pickup.

Wednesday, February 28, 2018

Classes at IPM House in 2018

IPM House provides a setting to put classroom knowledge to work. 
Just a short note to let you know about upcoming training opportunities at the IPM Experience House. In case you haven't heard about us, the IPM House is a hands-on training venue at the Texas A&M AgriLife Center in Dallas.  We are offering some excellent opportunities for learning in 2018.

Registration is open for the next three classes, and dates are happening soon, so check them out:

Rodent Academy will be offered March 6-8. A reprisal of a very successful class held last December, the Spring 2018 Texas Rodent Academy will feature guest trainer, Tim Madere with the City of New Orleans. An intensive three-day, advanced rodent control training course. Tim is one of the leading rodentologists in the country today, and has a lot to offer. The goal of the Texas Rodent Academy is to provide a highly focused and standardized approach to managing rodent populations through Integrated Pest Management (IPM).

Who Should Attend? The course is intended for pest management professionals, municipalities, universities, public schools, and food safety personnel involved in the rodent control programs. Class size is limited, so register soon.  Click here to learn more and for a link to registration. Cost of the three-day class is $300.

Sometimes IPM House provides the pests
along with instruction.
Introduction to termite control for new technicians on March 15 is designed to orient new termite technicians to the art and science of termite control. Termite control expert, Dr. Bob Davis, will be demonstrating practical field skills for setting up and executing a soil termiticide job. Kevin Keim, with Dow Agroscience, will provide an overview of termite baiting, including practical aspects of bait placement and installation. They are joined by Dr. Mike Merchant in the classroom to provide some of the basic biology of termites you need to know if you are to be on the top of your game. 

Owners, this is a great opportunity to get new or old employees ready for termite season. Half of the class will be classroom, and half will be in the field (at IPM House) demonstrating skills for performing a termite treatment. One termite CEU will be offered for those who complete the class. $55 Early registration. Click here to learn more and for a link to registration.

ACE Prep Class Coming to north Texas by popular demand, we are offering a souped-up, two-day version of the ACE Prep Class on April 12-13. This class is designed to help candidates prepare for the ACE exam. It provides a concise, well-rounded overview of the science of entomology and of the major pests that a PMP must know for the exam. The class provides 10+ hours of intensive classroom and lab training in pest control topics for any interested technician. You do not have to be pre-approved as an ACE candidate to take the Prep Class; however, it does serve as an excellent review and confidence booster for candidates who have been preparing for the exam. The exam will be offered at the end of the class to anyone who has applied for certification and paid the examination fee. Students wanting to sit for the exam are responsible for making arrangements with ESA prior to the class. Early registration cost of the two-day course is $100.

Click here to learn more and for a link to registration. Class size is limited to 30, so register early. Principal trainer: Dr. Mike Merchant.

General Household Pests Provides necessary Pest Category training for new apprentices and introduction to general pest control for new technicians. Topics to be covered include introduction to entomology and general orders of insects; general insect pests; mosquitoes; rodents and other animal pests. In addition, we will cover an introduction to IPM and pesticides, and equipment used in pest control. Hands-on activities include use of various sprayers and dusters, bait applications and situational problem solving. 8 hours. May date to be determined.

Lab experiences include microscopic examinations of pests.
Mosquito Control for PMPs provides an introduction to mosquitoes and mosquito biology. We’ll go through some of the basics of mosquito adult and larval identification, learn how to identify mosquito risk zones around the home and how to communicate with customers about risks from mosquito-borne disease. Different insecticide application methods and equipment will be demonstrated. Training will include both classroom, and hands-on and outdoor training at IPM Experience House. June date to be determined.

Application equipment selection, use and maintenance will demonstrate a variety of both new and old application equipment including sprayers, dusters and injection tools.  Experts from local manufacturers and distributors will discuss advantages and disadvantages of different tools, and show how equipment should be maintained and repaired.  July date to be determined.

Ant identification and biology. The first step in ant management is to know your enemy. In this class we'll review the major important ant species in Texas, and gain experience in ant identification using class microscopes.  August date to be determined.

Bed bug management. Get training in basic bed bug biology, learn about the latest research, and get sweaty installing encasements and searching for bed bugs.  Instruction from PMPs with lots of bed bug experience, this will be a very practical class for technicians.  September date to be determined.

ACE Prep Class will be offered a second time for those who missed our April class.  October date to be determined.

To keep informed of all upcoming classes and dates, join our mailing list.

Are bed bugs worse than we thought?

bed bugs and their feces on a mattress
Bed bugs produce an allergenic chemical called histamine to help them aggregate in sites like this mattress welt. Researchers worry that histamine may be adding another environmental allergen to our homes, like dust mites and cockroaches.
Bed bugs are trouble. They drink our blood. They soil our homes with their feces and cast skins. They keep us awake at night and add stress to our already stressed out lives. And they're revolting to most people.

Until now, if there was one positive thing that could be said about bed bugs, it might be that they haven't been found to carry communicable disease.  The impact of bed bugs seemed mainly to come down to sleepness nights and the economic sting of pest control expenses.

But newer studies seem to point to a darker side of these blood sucking pests. In 2011 Mississippi researchers Jerome Goddard and Richard deShazo scored postings from three popular bed bug websites.  They determined that nightmares, insomnia, anxiety, personal dysfunction and other psychological problems were common among online visitors. Some visitors to the sites were so severely shaken by their bed bug experiences that they scored high on a scale for posttraumatic stress disorder (PTSD).

In addition to mental health impacts, in 2014 bed bugs were implicated as potential carriers of the Chagas disease pathogen, Trypansoma cruziMichael Levy, one of the senior authors of the study, said "we've now shown that the bed bug can acquire and transmit the parasite [in mice]." But it remains to be seen whether bed bugs can pass the parasite to humans.  Currently Chagas disease is only known to be transmitted by kissing bugs--large blood sucking parasites most common in Central and South America. If enough people with Chagas disease are exposed to, and fed on by bed bugs, it's theoretically possible that bed bugs could become a more important vector of the disease in the U.S. than kissing bugs.

Also, we now know that the causative agent for trench fever and several other diseases, Bartonella quintana, can be acquired and passed on in bed bug feces.  The effects of trench fever range from mild to severe, even fatal. The disease has dogged soldiers in wartime for centuries, but until now doctors believed the pathogen was solely transmitted by body lice, insects prevalent among refugees, the homeless, and soldiers in camps and trenches. In a series of studies over the past six years researchers have been finding the bacteria in unexpected places. Traces of Bartonella DNA have been detected in head lice (like bed bugs, not common disease carriers), ticks, mites, and even cat flea feces.  Now the focus is on bed bugs. In 2015 French scientists found the bacterium could survive in bed bug feces for up to 18 days. As with Chagas disease, the evidence falls short of proof that bed bugs do or can carry this disease to humans; but in light of the ongoing bed bug epidemic, the data are worrisome.

Finally, thanks to a paper published this month by entomologists at the University of North Carolina, we now know that bed bugs are a major indoor source of the allergy-provoking chemical, histamine. Histamine was recently found to be one of the chemicals bed bugs use to attract other bed bugs into aggregations.  In this study researchers collected house dust from homes both with- and without-bed bugs, and tested the dust for histamines.

“Histamine levels in bed bug infested homes were at least 20 times higher than histamine levels in homes without bed bugs,” said Zachary DeVries, lead author of the paper. Even worse, histamine levels remained high, even three months after homes were treated with heat treatments.

“Histamines are used in skin and respiratory allergy tests... they cause a bump in skin tests and restrict breathing in respiratory tests,” DeVries said. In addition, he notes in the paper that histamine exposure can result in thinning of the epidermis, possibly posing significant skin effects.

While this study didn't look at health effects among people living with bed bugs, they speculate that risks posed by bed bug-produced histamine could rival the allergy- and asthma-causing effects of cockroaches and dust mites. They worry that because bed bugs live in bedrooms, where we spend the most amount of time indoors, the impacts might be multiplied.

This should remind us of our history with cockroach allergens. Not until the mid-1990s did public health experts and entomologists prove that cockroach allergens have a major impact on human health, especially in big cities. We've never looked at cockroaches in quite the same way since this discovery.

We may eventually have to rethink the way we think about bed bugs. Until then, keep tuned into bed bug news and continue to hone your bed bug fighting skills. After all, who more than your customers deserves a good night's sleep?

Tuesday, February 6, 2018

Reading your first scientific review paper

Feeling scholarly? Today might be the day to kick off your shoes, put up your feet, grab a favorite beverage and read a scholarly review paper.

The Journal of Integrated Pest Management is a relatively new, open access (meaning free!) publication put out by Oxford Press and the Entomological Society of America.  Its purpose is to provide a place for researchers to publish reviews of the literature concerning significant pests.

Most of the papers appearing in the JIPM summarize current knowledge about the control of an agricultural or horticultural insect, weed or disease pathogen.  But this month a paper of interest to pest management professionals was published on brown recluse spiders.

Rick Vetter and Stoy Hedges, both long-time friends of the pest control industry, have teamed up to write a paper on current practical knowledge about the biology, importance and control of Loxosceles reclusa, better known as the brown recluse. Although both authors are well-published, Hedges admits the paper marks an especially sweet accomplishment for him, as his first paper in a refereed scientific journal.

What's a refereed article?

If you're a PMP and never read a scientific journal paper before, this could be a good one to start with.  But first, just what is a "refereed" journal article? If you've ever heard the old line, "publish or perish" as applied to college professors, the term publish generally refers to refereed journal articles or scholarly books. The "perish" in the saying is almost literal and refers to holding onto or losing your job as a professor. To avoid perishing professionally, it is almost universally true that professors must write refereed articles.

A refereed article is first and foremost a scholarly paper, written by someone who has become learned through study and/or research. Scholarly papers are not meant to entertain, but to precisely explore, inform or enlighten a reader on a topic.  Scholarly papers don't have to be dull or difficult to read (though many are), but they do have to be based on data, sound observation or logic. To ensure this is the case, all must go through a rigorous process of peer review and critique by fellow, equally qualified scientists or scholars.

To publish, Vetter and Hedges first wrote their paper and submitted it to the editor of the JIPM.  The editor then read the paper, made sure it was readable, whether the authors followed journal instructions, and whether it was appropriate for the journal. Once it passed the editor's initial review, willing reviewers with knowledge of spiders or urban pest control were identified and the paper was sent out for review.  Three (usually) reviewers read and commented on the paper, offered suggestions and told the editor whether they thought the paper was OK, whether it needed revision, or whether it was so bad it shouldn't be published. Only after it passed the reviewers' and editor's approval, was the paper approved for publication. Many, if not most, publications get rejected by reviewers at least once. If you look closely at these papers you can almost see the blood, sweat and tears... sometimes from both authors and reviewers.

By the way, reviewers are volunteers. If you are a professor or scholar who has previously published you might be asked to review a paper in your published field. This in itself is considered a scholarly activity and professors are graded by their institutions, partly, on how many papers they have reviewed in a given year. Reviewing a paper is a lot of work, but science could not advance without good reviewers.

The abstract

Most scientific publications have abstracts, usually at the beginning of the paper.  This is one of the most useful parts of a scientific paper. The abstract should summarize the reason for, and the key findings of, the paper.  Unlike a book description on the dust cover of a novel, the abstract should give away the ending. It should be short, but thorough enough to tell the reader what the paper is about, and its conclusions.  In a given year I read relatively few papers from start to finish, but I read a lot of abstracts. They are great time savers.

Vetter and Hedges' paper is a particular type of scholarly article called a literature review. Rather than writing about original research they conducted, they have summarized others' research and put that information into context. As the authors say in the abstract, "...we review biology and life history of the brown recluse spider as it relates to pest management as well as control measures as they pertain to an IPM strategy..." The best literature reviews are written by scholars who know their subject matter well enough to explain not just what another researcher published, but why it's important.  Literature reviews are one of the most important types of publications for new readers on a topic.


A literature review is typically peppered with citations--abbreviated references to refereed papers or books. You'll see lots in this paper. Citations generally include the first author, or two co-authors names, and the year of publication. For example, (Thoms and Scheffrahn 1994) refers to a paper by two researchers, Ellen Thoms and Rudi Scheffran, published in 1994 on the control of pests using Vikane gas.  The full reference citation is found in the section in the back of the paper, usually in the section labeled as References Cited. When the article has more than two authors it will be referred to by the primary author's name followed by et al. For example, Atkins et al. 1958 refers to a paper by J.A. Adkins and three other collaborators, Wingo, Sodeman and Flynn, published in 1958 on "necrotic arachnism" (spider bites that result in flesh-eating, slow-to-heal wounds).  Sounds like a real page turner.

Like all of us, scientists have egos; and having your name first in the list of authors is a badge of honor. Being first usually means that you led the study or done most of writing on the paper.  Surprisingly, being last in a list of authors is often considered second best. Last place is often reserved for the supervising professor (if the first author is a student), or someone responsible for securing project funding. Being stuck in the middle of a long author list is like being the "middle child"--more likely to be overlooked and forgotten.

Let's Read

That's really all you need to know to read this paper. It's more engaging (and you are less likely to fall asleep) if you use a highlighter to mark things new to you, or which might be relevant to control of these spiders. For example, several years ago I did some insecticide tests on brown recluse spiders, so I was especially interested in the review of insecticides that others found effective. I also know from talking with fumigators that spiders are notoriously hard to kill with fumigants. So I was interested to learn that Thoms and Scheffran determined that a 1.5X rate of Vikane was needed to kill brown recluse spiders. I highlighted both of these sections.

Lastly, remember that even writers of scholarly papers are ordinary people--sometimes a little geekier or nerdier than some of your football-watching buddies, but still just people who put their pants on one leg at a time. Even scholars make mistakes, overlook data, and draw bad conclusions. Even though peer review is a rigorous process, it's not perfect. To me, that makes reading science papers more interesting. It means that they should always be read critically, with an eye to your own experience and to common sense.

When you're done, take the paper and file it. I have a My Library folder on my computer. This article went into a sub-folder on spider papers.  Whatever system you use, put it somewhere you can find it later. Otherwise you will forget most of what you've learned and highlighted.

So grab a cold one and dig in. There's a lot to learn about spiders in Vetter and Hedges 2018.

Wednesday, January 3, 2018

ACE Prep Class offered next week

Students taking their exams after the 2012
ACE Prep class at Texas A&M. 
I often get asked how best to study for the ACE exam, and if a class is ever offered. One of the places to get ACE training each year is the Texas A&M University Urban Pest Management Conference. If you're not familiar, this is the biggest CEU opportunity offered by the A&M entomology department, and (we think) one of the best training opportunities for PMPs in the state.

As of this morning enough students have signed up for this class to make it a go, and there is room for more.  If you are interested in participating, just go to the A&M Conference website and sign up.  You will be registering for the whole conference that runs from January 10-12.

ACE training runs all day on Wednesday, Jan 10, beginning at 10:15 am.  We will cover as much of the ACE exam material as we can in one day.  On Wednesday, we will offer an opportunity to take the ACE exam for anyone who is ready to take it.

Not enough notice?  I plan to offer the prep class as an IPM Experience House event at our Texas A&M AgriLife Center in Dallas twice in 2018 (dates to be determined). If you are interested, drop me an email--or even better, join our mailing list at the IPM Experience House website. This will get you notified of all IPM House activities coming up in 2018 if you join the list.

Monday, December 11, 2017

Lessons from Rodent Academy

Dr. Bobby Corrigan delivers his introduction to rodents sharing his favorite Sherlock Holmes quote. Much of the class is
devoted to training students to be better observers of rodent behavior. 

Bobby Corrigan refers to himself professionally as a rodentologist, though he's slow to admit as much to just anyone. He describes the typical conversation with someone next to him on a plane, or at a casual encounter at a party:

"So, what do you do for a living?" 

"I'm a rodentologist."

"Oh, how nice!" [crickets]... End of conversation.

I for one am glad the world has rodentologists. Because we need them. Without a rodentologist we couldn't have offered the three day course held last week at the Texas A&M AgriLife Center at Dallas. And without rodentologists we wouldn't have a clue about how to manage these intelligent but unwelcome house guests.

When I first met Corrigan at Purdue University in the early 1980s he was the only grad student working on rodents in a department of entomologists, a pattern that seems to have continued throughout his career.  

"Despite their acknowledged importance from a public health perspective," Corrigan said, "I saw there was little in-depth information about how to control rodents for people working on the city, county and school level." While there seemed to be lots of money and resources for insect-related pest problems, Corrigan was always asking "What about the rodents?"

Corrigan's persistence  paid off in 2003 when he was awarded a $5 million grant working with the City of New York to help establish the Rodent Academy course. Since then, the NYC Academy has been offered twice a year, filling up every time it's offered. The classes have become legendary for their intense classroom sessions and nighttime tours of Norway rat-infested streets, parks and alleyways of the big Apple. Since it was first offered the Academy has trained over 2,000 people in rodent management.

In recent years Corrigan has helped put on Academies in other locations including Seattle, Philadelphia, San Diego, and Washington, DC. Last week was the first time the course was offered in Texas.  And if the response of this year's attendants of the first Texas Rodent Academy is any indication, the Academy will be offered again.  

Corrigan seemed pleased with his first Texas class. Very well organized [by Extension program specialist Janet Hurley], excellent faculty, "Almost like an experienced academy," he said.

Although Dallas differs from NYC in the density and intensity of infestations, rodent problems are based on the same template, says Corrigan. "Even though the two cities feel different and look different, from the rodent's perspective both make good homes.  Both produce garbage and have plenty of food in dumpsters, and both cities have people who litter, so the Academy curriculum works [in Texas as well as New York].  

An important part of the class arrives when students break into
groups to develop a rodent management plan for the IPM House.
One way that Texas does differs from New York is in rodent species composition. New York has massive problems with the large, bold Norway rat, as well as the adaptable and highly invasive house mouse.  While both rodent species are present in Texas, the secretive and acrobatic roof rat predominates in most urban communities here. One of the guest speakers for this year's Academy was Mike Swan, of Entex Pest Solutions in Richardson.  Swan showed pictures and described a recent encounter with a massive roof rat colony in a local suburb.  After an intense baiting campaign, the company ended up removing over 700 dead roof rats from several adjoining businesses in an upscale neighborhood.

Emory Matts, of Steritech/Rentokil in Dallas also assisted Corrigan with his talk on protecting our food supply from rodents.  Touting the U.S. Public Health Service Food Code as "a good read," Matts surveyed many of the laws protecting food safety and provided IPM tips for inspection and control programs.  He emphasized the importance of knowing who is auditing your customer's food handling premise, because standards for indoor and outdoor bait placement and service frequently differ depending on the auditing agency.

Application Rates

After establishing that nearly everyone in the class regularly used rodent baits in their business, Corrigan stumped the group with a simple question, "What's the appropriate application rate for rodent bait?" [crickets]...  The number one reason for poor rodent control, he said, is failure to estimate rodent density, and follow label application rates (oz. bait/area treated) based on the estimated rodent population.  Typical rodenticide labels require users to apply 3 oz bait/30 ft (for low infestations), up to 16 oz bait/15 ft (severe infestations). Very few PMPs know these application rates, with the result that few apply sufficient bait when going after an established rodent population.

Dry Ice

One of the biggest developments in rodent management in many years occurred this summer, Corrigan said.  After prolonged discussions with the National Pest Management Association, in late June 2017 the U.S. EPA approved a label for "Rat Ice," dry ice for asphyxiating rodents in burrows. When placed into a rodent burrow and covered with soil, pelleted dry ice is an extremely effective and low-risk treatment for ground-nesting rodents.  Until now, the only barrier to its use was that dry ice was not registered as a pesticide and technically could not be used in commercial pest control.  

While there is still some confusion about where and how to purchase dry ice legally for rodent control, an EPA-approved label for "Rat Ice" is now available. Bell Labs is sponsoring the new label as a service to the industry and says it is working on state registrations.  Bell Labs will provide a more comprehensive update, including launch details, soon, according to a recent news update in PCT magazine. [Note: According to Texas Department of Agriculture regulator, Michael Kelly, the Rat Ice label has been registered in Texas.]


In Corrigan's opinion, another one of the most significant improvements in rodent management in recent years is non-toxic baits for biomonitoring. These non-toxic baits allow PMPs to minimize risk of baits to non-target organisms while identifying when and where rodents are present. Many of the newer baits also include bio-luminescent dyes that become brilliant "glowscats" when captured in the glow of one of the new LED blacklight flashlights.

Jose Dolagaray from Arrow Exterminators
in Georgia displays a dead roof rat discovered
during his outdoor inspection of the IPM
Experience House.
These non-toxic, bio-luminescent baits now act as tracking baits, providing information about three critical items: a) high-activity rodent trails; b) distances traveled, and; c) possible zones where nests are located. Consequently, glowscats provide clues to help you maximize effectiveness of trap and bait stations placements. Another benefit is when bioluminescent baits are placed outdoors only, glowscats found indoors provide evidence of penetrations in the building envelope.

As an added bonus, Corrigan said that in every instance that he's observed, rats prefer these toxicant-free baits. They are inevitably the first baits eaten from a bait station. He believes they can help jump-start bait-shy rodents to feed when placed in stations on the outside of rodenticide-containing blocks and soft-baits.

IPM House

The IPM Experience House provided the hands-on setting for excursions on each of the three days. Because the house is situated next to an un-mowed culvert, and bounded by a minimally maintained tree nursery and garden area, rodent life outside was... interesting. Students caught glimpses of cotton rats, Sigmodon hispidis, and saw unmistakable roof rat burrows, runways and rub marks around parts of the building perimeter. A water filled bucket proved deadly for an inquisitive roof rat and provided an opportunity for participants to practice their rodent ID skills. Most agreed that being able to practice their new observation skills around the IPM House was a valuable part of the training.

The class covered much more than can be covered here, exhausting students by the end of the third day. If you want to learn more about rodents before the next academy comes along, consider purchasing a copy of Corrigan's very informative book: Rodent Control: A Practical Guide.

For more information about IPM Experience House and upcoming PMP classes, check out the website and consider signing up for the mailing list. A new listing of 2018 classes is coming soon.

Monday, November 20, 2017

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.


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.