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).

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.