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).