Tuesday, November 25, 2014

What's news in entomology?

Portland, Oregon, site of this year's ESA
meeting, is a short drive from many natural
wonders, including Punch Bowl Falls in the
Columbia Gorge area.
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. 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 year the meetings were at the Portland Oregon Convention Center, with over 3,400 entomologists and about 3600 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 you, here are highlights from the very small slice of the conference that I experienced:
  • In Michigan and other Midwest states, an insect called 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.  With EAB poised to invade Texas, this is especially good news.  Over the past ten years, several effective treatments have been discovered for this beetle.  Emamectin benzoate (TREEage), imidacloprid (Merit), 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 which 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 2014 papers highlighted at this year's meeting suggest that fire ants and Argentine ants, two of our worst invasive ant species, have finally 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 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% 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.  Imagining 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! Bait technologies have revolutionized cockroach and ant management, but 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 in the near future.  
  • 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 3 months.  The pathogen also remained with the bugs even through molting. At the same time we were learning these results, Penn State researchers announced last week l that 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 U.S.  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 new twist on the bed bug problem.
  • The ACE (Associate Certified Entomologist) program at ESA is expanding this year with the launch of a new International ACE program.  A new test has been developed for PMPs outside the U.S. wishing to become certified.  In addition, the ESA is considering adding an ACE-Public Health certification to its program.  Some of the initial discussions about this option took place last week at the meeting and it appears that the National 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 several very good talks last week 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) pest management professionals, this is something I need to do. Plus, last month 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, here's my "handle" @mikemerchant.  I invite you to follow me on Twitter as I try to find my place in this increasingly wired world.

No comments: