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.