Another three years of Termidor Section 18 label

Pest management professionals on the front line of the battle with tawny crazy ant (TCA) (Nylanderia fulva) can breath a little easier.  Last Friday the U.S. EPA issued a Section 18 quarantine exemption to allow Termidor® SC to be applied as an extra wide treatment zone around homes and buildings in infested Texas counties.

The Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) is perhaps the most important law governing pesticide use and pest control in the U.S.  Section 3 of FIFRA has to do with registering insecticides, and establishes the process by which different pesticides usually get their label approval. This is why you may hear people refer to the standard label on a pesticide container as a "Section 3" label.

Sometimes states have a need for a new use, or pest, that is not allowed under a regular Section 3 label.  When that occurs, the state may request an amended label, called a Section 18 emergency, or Quarantine, exemption.  Section 18 of FIFRA authorizes EPA to allow an unregistered use of a pesticide for a limited time if EPA determines that an emergency pest condition exits. An emergency condition must be an urgent and non-routine situation where 1) no effective registered pesticides are available, 2) no feasible alternative control practices exist, and 3) the situation involves the introduction of a new pest, will present significant risks to human health or the environment, or will cause significant economic loss.

Dead tawny crazy ants pile up around a Termidor® treated
building perimeter.  Once enough dead ants accumulate, other
ants can cross the treatment zone on the bodies of their nest
mates (photo by Jason Meyers).

Several years ago BASF found that Termidor® SC Termiticide/Insecticide was highly effective at killing TCA, but did not always  effectively keep TCA out of buildings.  This happened because TCA numbers were so great in infested areas, that dead ants would pile up around the treated perimeter of buildings. As dead ants accumulated on the allowed one-foot out treatment zone, other ants would simply crawl over the zone on the dead bodies of their nest mates.  It became apparent that the standard one-foot-up and one-foot-out perimeter treatments allowed under the Termidor® Section 3 labels were inadequate to protect homes and businesses from invasion by this ant.

The latest Section 18 granted to the Texas Department of Agriculture (TDA) allowed applications to be made as a 10-feet-out (on sod) by 3-foot-up perimeter treated zone.  This last exemption ran out on November 1 2015, and anxious PMPs have been waiting for its renewal since.  This week's announcement will allow the 3-foot-up and 10-foot-out Termidor® SC use this year when ants become active again, according to Extension entomologist Dr. Paul Nester. Nester noted that the label restricts users to two applications per year per structure, at least 60 days apart.  Most people, he said, apply first in late June, when ants become troublesome, and then again in late August.

The Section 18 label restricts its exemption to infested Texas counties only:

For control of tawny crazy ant species associated with man-made structures in Texas within the counties of Bexar, Brazoria, Brazos, Cameron, Chambers, Comal, Fayette, Fort Bend, Galveston, Hardin, Harris, Hays, Hidalgo, Jefferson, Jim Hogg, Liberty, Matagorda, Montgomery, Nueces, Orange, Polk, San Augustine, Travis, Victoria, Walker, Wharton, Williamson, and to include additional counties where positive identification has been made (by Texas A&M entomologists).

The list will change as the number of infested counties goes up (and it will), so it's a good idea to check the current range map maintained at Texas A&M.

Though there are other fipronil-containing sprays, only Termidor®  SC has the expanded perimeter Section 18 treatment option.

According to Nester, most applicators use Termidor® or Taurus® treatments in combination with yard treatments of either dinotefuran, lambda-cyhalothrin (or other pyrethroid), or a fipronil granule.

This week's announcement came from Dale R. Scott, Director for Environmental and Biosecurity Programs at TDA.  He encourages anyone with questions to contact Kevin Haack (TDA Coordinator for Pesticide Evaluation and Registration) or Mike Kelly (TDA Coordinator for Structural Programs).

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.

Tawny crazy ant name proposal hits streets

Tom Rasberry points out one of the early known
infestation sites of Nylanderia fulva close to the
Houston ship channel in Houston, TX (2004)

The crazy ant first discovered in Texas by PMP Tom Rasberry, may be getting a new common name.  As I reported in an earlier post, the way for a new name was opened with the recent publication of research firmly identifying the ant variously known as the Rasberry crazy ant, hairy crazy ant or Caribbean crazy ant (depending on what state you are from).  As it turned out, the ant was decidedly NOT the Caribbean crazy ant, Nylanderia pubens, but another species originally described from Brazil, Nylanderia fulva.

This week the Entomological Society of America's (ESA) committee on common names approved a new common name which has received lukewarm support.  The last step before formal acceptance of the official common name (which I and most entomologists will likely start using) is for the proposal to go before ESA membership for comment.  The proposal is located at http://www.entsoc.org/PDF/2013/names/tawny-crazy-ant.pdf, and does a pretty good job of detailing the background of the controversy and listing authorities who both support and oppose the new name.

If you are an ESA member, this is your last chance to let your voice be known. Please submit any comments by March 13, 2013 to Greg Dahlem, the committee chair, at dahlem@nku.edu.

Interestingly, there are colleagues of mine from Texas A&M who both support and oppose the new name.  Dr. Bart Drees (Texas A&M AgriLife Extension) supports the name change, and Dr. Roger Gold (Texas A&M University) opposes it, along with (not surprisingly) the Rasberry family.  Dr. Gold thinks "tawny" a little dull, and argues that a more descriptive name is needed.  He suggests "Brazilian crazy ant," to commemorate where the ant was first discovered.  I think I like Brazilian crazy ant better than tawny crazy ant; but I have another name to propose.  I suggest we call it the "troublesome crazy ant".  I'm sure that's one name most of the people who encounter this tiny invader could agree on.

Crazy ant name gets crazy

A closeup of Nylanderia pubens and the male
genitalia (bottom) of N. fulva (left) and pubens.
Based on the recent paper, invasive crazy
ants found in the southern U.S. in recent years are
thought to be N. pubens, with the proposed
common name, tawny crazy ant. Photo from Gotzek
et al. 2012.

One of the most impressive new structural insect pests to emerge in the southern U.S. over the past few years (besides the bed bug) is a new ant, called variously, the Rasberry crazy ant, the Caribbean crazy ant, and the hairy crazy ant.  According to Texas A&M University graduate student Danny McDonald, this ant finally has a definitive name... well at least a definitive scientific name.  

Dietrich Gotzek and colleagues from the Smithsonian Institute and Towson University in Maryland (2012, PLoS ONE 7(9): e45314), examined ants from Texas, Louisiana, Mississippi and Florida, and concluded that the ant we know in Texas as the Rasberry crazy ant is not a new species, but a previously described ant from South America, Nylanderia fulva.  Their conclusion is based on statistical analysis of numerous body part characters (morphometric analysis), DNA comparisons, and comparison of the shape and condition of the male ant's genitals. The researchers report that there is no reliable way to distinguish N. fulva workers from the worker ants of the closely related, so called "Caribbean crazy ant", N. pubens.  The Caribbean crazy ant is the species that at one time was thought to be, or be the closest thing to, the Rasberry crazy ant in Texas.  I'm no expert on the techniques used in these studies, but based on the agreement between three independent methods of settling the question, and Danny McDonald's seal of approval, the matter appears to me to be definitively settled.  

So what is Nylanderia fulva, and what do we know about it?  This ant, which has never been given an English common name, is from South America--probably from the southern part of the continent according to the study's authors.  It was first described from Brazil, but major population explosions of this ant are thought to have occurred in Columbia, S.A. as well as Bermuda, the St. Croix Islands, and possibly southern Florida. One of the characteristics of this ant that distinguish it from its Caribbean cousin, N. pubens, is its ability to develop high populations and become a serious pest.

The Controversy

If entomologists have settled happily on a scientific name for this ant, it's hard to find anyone who is happy about the common name for this ant. So what exactly is a common name and why is it so controversial? Most insect common names have probably come from the general, non-science public. The problem with common names is that frequently people from different social circles, or language groups, or regions have given different common names for the same insect. Also, the same common name may refer to different organisms.  Of course this drives the obsessive-compulsive scientific community absolutely batty. 

Since 1903 professional entomologists have attempted to bring some order to common names of insects via rules and an approval committee and a formal list of acceptable common names.  The Entomological Society of America (ESA) currently maintains a list of approved common names.  This makes entomologists happy, but can rub some people the wrong way, especially those who get attached to a favored common name or spelling (e.g., the media who want to write "bedbug" instead of bed bug).  

Such is the case, for some, with Nylanderia fulva. The authors of the paper have recommended that the ant should be called the tawny crazy ant, because of its light brown color. But this so-called common name is anything but in common use. At least three common names have been applied to this ant since recent reports of it in the U.S.  In Florida it has been referred to as the Caribbean crazy ant (a mis-identification, now cleared up by Gotzek's paper).  In Louisiana it has been referred to as the hairy crazy ant.  And of course the pest control industry in Texas has known it for the past 10 years as the Rasberry crazy ant, in honor of Tom Rasberry, the sharp-eyed PMP who first brought it to the attention of Texas A&M researchers and many others.  

Friends of Rasberry argue that the name Rasberry crazy ant should be the official name because it has been in general use the longest and it honors the person that pointed it out (at least in Texas) to professional entomologists.  Others don't especially like the common name because it's confusing to people who don't know Rasberry's story, or who think its an ant pest found on berry crops. Others don't accept the Rasberry name because it arose locally, and has no meaning to folks in other areas who have known about the ant for many years in say, Florida or Mississippi or Bermuda. 

I'm mostly happy to stay out of the controversy and wait until the dust settles; but I will likely use whatever name the ESA settles on. Scientists, after all, have been the originators of many of the common names in use today.  At the same time I sympathize with those who object to entomologists (who generally dislike common names in the first place) choosing a fusty, and rather nondescript name. This may be one of the reasons the botanist de Candolle, writing in 1868, said, 

"Every friend of science ought to be opposed to the introduction into a modern language of names of plants that are not already there, unless they are derived from a Latin botanical name that has undergone but a slight alteration."

Some Useful Links

To learn more about why Nylanderia fulva is such a pest, see the Texas A&M University website on this insect.  Also, Alex Wild has created a useful and beautiful set of directions on how to identify N. fulva. The photos from this site will give you a better appreciation of the fine distinctions and types of characters used to distinguish ants at the species level.