Editor’s Note: The following article originally appeared on Mike Merchant’s blog, “Insects in the City,” which can be found at http://insectsinthecity.blogspot.com. The blog offers readers news and commentary about the urban pest management industry and is excerpted here with permission of the author.
Some 20 years ago, shortly after being hired as extension entomologist, I figured I would save money by not attending the annual conference of the Entomological Society of America (ESA). In retrospect, that decision ranked as one of the poorest choices of my professional life.
The year I skipped ESA was like being lost in space — as if I had missed out on all the advancements in my field for the previous 12 months. The ESA annual conference is the best way I know to keep in touch with colleagues and learn about new advances in the science of insects. The meeting covers everything from the most basic scientific theory to very practical topics in pest control. I haven’t missed a meeting since that lost year.
This past year the conference was at the Portland Oregon Convention Center, with more than 3,400 entomologists and about 3,600 papers and posters. Every year after the meeting I like to go over my notes and highlight what I think were some of the most important bits of information. So, as my gift to PCT readers, here are highlights from the very small slice of the conference that I experienced:
- In Michigan and other Midwest states, the Emerald ash borer (EAB) has been devastating ash trees since 2002. Researchers are finding, however, that after a decade of expanding its range, some “good” bugs are coming to the rescue. In the center of its new territory, parasitic wasps, both native and imported, have reduced EAB densities five-fold over their peak in 2005. During the past 10 years, several effective treatments have been discovered for this beetle. Emamectin benzoate (TREEage), imidacloprid (Merit) and dinotefuran (Safari) provide multiple years of control with one application. There is even an effective organic treatment. Azadirachtin (TreeAzin 2) has been found to control EAB larvae for one year.
- Molecular genetics has become a major, if not dominant, subject of presentations at the annual conference. This year’s keynote speaker, Fred Gould of North Carolina State University, spoke of the successes and potential of genetic pest management. The science started with sterile insect releases that eradicated the screwworm fly and Med flies as early as the 1960s. More recently genetic engineering has been developed to insert genes into a population of insects that might reduce its ability to be a pest. For example, genes have been discovered that might prevent a mosquito from becoming infected with a virus like West Nile. Mosquitoes have been targets for this kind of genetic engineering research in the past 20 years, but a major challenge has been how to speed up the spread of desirable genes into the whole population. Now a new version of this technology promises to solve this problem. According to Gould, special genes have been designed that not only insert desirable genes into pest insect DNA, but also, like a computer virus, replicate itself within the pest’s chromosomes. Called “homing endonuclease genes,” this technology promises almost immediate results, unlike the older technology that might take years to take hold. With this technology it is conceivable, says Gould, to completely eradicate a “bad” insect species. Of course, implementation of this technology raises ethical questions, for which scientists will have to answer. If it works, it would be scary powerful.
- Have invasive ants finally met their match? Two papers highlighted at the meeting suggest that fire ants and Argentine ants finally have been out competed by other ants. When encountering fire ants, the tawny crazy ant (TCA) covers itself with formic acid, which forms a coating that protects it from fire ant venom. Researchers tested the importance of the TCA anal excretions by covering their little ant anuses with nail polish. (I’d like to see how they did that!) When anuses were blocked, almost half of the ants battling fire ants died. When not covered, only 2 percent of the TCA died in battle with fire ants. (Cool!) Similarly, the Asian needle ant is out-competing Argentine ants for prime nest sites. They do this by having better cold tolerance than Argentines. Too bad that both of these new invaders are bad pests on their own. People living with tawny crazy ants in Texas say they would rather have the fire ants. And Asian needle ants are supposed to have a wicked sting.
- New insecticide formulations come around less often than new insecticides, but this year Syngenta Professional Products appears to have developed a promising new formulation for ant control. Based on polyacrilamide gel, the formulation consists of water-storing crystals that can hold an insecticide for long periods of time. Add sugar, or a protein, and you have a product that can be applied dry like a granule, and expand with exposure to water into a highly attractive gel bait. Imagine being able to bait an entire yard for sugar-loving ants with gel bait in the same amount of time that it takes to put out fire ant bait. Reported by Purdue entomologist Grzesiek Buczkowski, this formulation could provide better control of sugar- or protein-loving ants, including Argentine ants, odorous house ants, crazy ants and rover ants, among others. This product is not yet on the market.
- Now imagine baiting for bed bugs! Because bed bugs feed only on blood, baits for bed bugs have been seen as impractical. Maybe until now. Research by Alvaro Romero, urban entomologist at New Mexico State University, appears to have solved at least one step in the complex problem of bait development for bed bugs. Alvaro’s group found a synthetic substitute for blood that bed bugs will feed on, and even gain weight with. If an effective method of delivery can be found, this could be a major advance in bed bug management at some time in the future.
- Ebola virus was the subject of an informal symposium put together at the last minute by extension entomologist Nancy Hinkle, University of Georgia. The official line from the Centers for Disease Control is that no insect is a known vector for Ebola virus. However, after a quick literature review of the potential for insects to serve as Ebola vectors it became clear that the book is not closed on this subject. While some research shows that Ebola transmission from mosquitoes is unlikely, medical entomologists are concerned about the potential for flies to serve as mechanical vectors of the virus. In Africa, where several species of flies are commonly seen feeding on eyes and wounds of people, the potential for mechanical (carried on the external portions of the body rather than in the saliva or feces) transmission is feasible. The group also discussed the potential for cockroaches and bed bugs to serve as Ebola vectors. To date, it appears that no one in Africa, or with the CDC, has specifically investigated these potential vectors. The symposium participants agreed that the issue is important enough to justify writing a letter to the CDC urging funding for research into these pests.
- Speaking of human diseases, one of the more surprising announcements at the meetings this year was research by Brittany Blakely, of New Mexico State University, which showed that bed bugs may be able to transmit Trypanosoma cruzi, the pathogen that causes Chagas disease. If experimentally demonstrated with live animals, this would be the first human disease known to be carried by bed bugs. But this is still just a theory. What Blakely and her team showed was that when bed bugs were fed on infected blood, the pathogen could be found in their bodies for at least three months. The pathogen also remained with the bugs even through molting. At the same time we were learning these results, Penn State researchers recently announced they had successfully infected mice using bed bugs as a vector for T. cruzi. Because bed bugs are primarily human feeders, they would have to first feed on an infected person to become infected. According to the Red Cross, there may be as many as 100,000 people with the parasite in the United States. If bed bugs are proved to be capable of transmitting the disease between two humans (which hasn’t happened yet), this could be a significant twist.
- The ACE (Associate Certified Entomologist) program at ESA has expanded with the launch of a new International ACE program. A test has been developed for PMPs outside the U.S. wishing to become certified. In addition, ESA is considering adding an ACE-Public Health certification to its program. Some of the initial discussions about this option took place at the meeting and it appears that the American Mosquito Control Association is interested in the prospect of having ESA develop a test and certification.
Lastly, I can’t ignore the buzz about the Twitterverse any longer. I have to admit that I’ve been slow to jump on the Twitter bandwagon, but after listening to several good talks I think I’ve been convinced to take the leap. I’ve been told that if I want to stay in touch with you and other (especially young) PMPs, this is something I need to do. Plus, at our fall IPM training conference I felt old when our new extension turfgrass specialist casually put up his Twitter handle at the end of his talk and welcomed people to follow him. Not to be outdone by a young whippersnapper, my “handle” is @mikemerchant. I invite you to follow me as I try to find my place in this increasingly wired world.
ESA Recognizes Dr. Nancy Hinkle for Pioneering Work with ‘Invisible’ Bugs
University of Georgia entomologist Nancy Hinkle has built a career as a well-respected veterinary entomologist, but it’s her work with “invisible” insects that gained her esteem outside academia.
This fall, the Entomological Society of America presented Hinkle with its 2014 Recognition Award in Urban Entomology for her studies of insects considered pests in the human environment — including pests that are sometimes imagined.
Hinkle has worked as a medical-veterinary entomologist in the UGA College of Agricultural and Environmental Sciences’ entomology department since 2001, primarily with insect pests that affect the poultry industry. Over her career, she also has researched various insects that affect humans — from fleas to head lice to mosquitoes.
Because of her interest in blood-sucking insects, Hinkle has become one of the nation’s leading experts on delusional parasitosis, a psychological condition in which the individual believes to be infested with insects despite the fact that there is no evidence of infestation.
“She’s kind of a focal point for professionals who work with people affected by this condition,” said Wayne Gardner, a fellow UGA professor of entomology who nominated Hinkle for the award. “She broke it down and talked about the different issues that can cause it.”
Her interest in the subject started in the 1980s when her doctoral adviser at the University of Florida — flea researcher Philip Koehler — received a sample he did not have time to identify. He handed it off to Hinkle, who spent hours trying to identify the insect only to realize later that there was nothing in the sample to identify.
With funding from the Florida Entomological Society, Hinkle found that it wasn’t uncommon for pest control operators and labs to be asked to solve imaginary pest infestations.
As an Extension entomologist, she often received — and still receives — calls from worried individuals who believe they are infested with an unknown skin parasite. This condition is sometimes found in people with no other signs of mental illness or substance abuse.
She summarized her experience with invisible bugs in the 2010 Annual Review of Entomology article “Ekbom Syndrome: The Challenge of ‘Invisible Bug’ Infestations.” In 2011, Current Psychiatry Reports included her article “Ekbom Syndrome: A Delusional Condition of ‘Bugs in the Skin’” to help mental health professionals understand the condition.
“It is always gratifying to be recognized by one’s peers,” said Hinkle, who won the society’s regional Recognition Award for Urban Entomology in spring 2014. “My advantage is working on pests everyone dislikes — fleas, ticks, lice, mites, spiders and such.”
In addition to her work with human and animal ectoparasites and delusory ectoparasites, Hinkle maps the geographic range of brown recluse spiders in Georgia and illustrates how rare the feared spiders are in the state. Currently, Hinkle is working on control methods for avian mites, pest flies and darkling beetles that carry salmonella and can transmit the bacteria among poultry flocks.
“Dr. Hinkle’s primary responsibility is working with the poultry industry and with veterinary or medical entomology (research), but in this work she encounters a number of problems that affect our urban clientele,” Gardner said. “Even though it’s not her primary responsibility, Dr. Hinkle works to address each of those problems brought to her, and she addresses them quite effectively.”
Since her interests span the worlds of veterinary, agricultural and urban pest problems, Hinkle frequently addresses pest management conferences around the country. She has made more than 300 presentations to pest control groups, including 22 state associations, the National Conference on Urban Entomology, the Purdue Pest Management Conference and the National Pest Management Association.
Hinkle received bachelor’s and master’s degrees in medical entomology from Auburn University and a doctorate from the University of Florida.
The author is an entomology specialist for Texas AgriLife Extension. Email him at email@example.com.