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).

Some competition

After all the political discussion this week in the media about "vulture capitalism" I'm reminded that battles in the pest control industry can become just as heated as any political campaign.  According to an article this week in Pest Management Professional, after 21 months of legal battles between BASF and rival manufacturers, it looks as if at least one company has won the right to sell generic fipronil.

Control Solutions is currently selling a granular and SC formulated version of fipronil that will compete with Bayer Top Choice and BASF Termidor.  The current label for Taurus G (granular fipronil) lists only fire ants as a target pest, although additional pests may be added in the future.  Like Termidor, the Taurus SC label includes instructions for perimeter pests and termite control.  For termites it allows for an "Exterior Perimeter - Localized Interior" treatment, a form of treatment pioneered by BASF. According to Control Solutions, both products are now available through most distributors (Univar is not yet selling the Control Solutions' fipronil, pending additional negotiations) in Texas.

I don't usually post about battles between chemical manufacturers over market share; but as I pointed out in an earlier post, this is a big deal for the pest control industry. Patent expiration always leads to price reductions for the industry, and this one will be no exception. And when it comes to a leading termiticide, we're talking lots of money.

For its part, BASF has worked hard to protect its patents and develop new uses and formulations to stay ahead of the competition.  Termidor DRY is one example of a unique BASF formulation, as is a new formulation that will require less trenching and less water for perimeter treatments.

I won't weigh in on whether it's a good idea to go with a less expensive, off-brand insecticide; however I will make a generic observation about generics. Everyone should know that despite having the same active ingredient, generic products are never identical to the original.  For example, the way an active ingredient is formulated will vary from manufacturer to manufacturer.  Formulations include solvents, adjuvants and stabilizers to make the technical ingredient easier to mix, store and use. If you choose to switch to a generic product in your business, be sure to make sure it's giving you the same performance you expect from the original. As with any new product, it's important to decide what works best for you and your business. After all, wise decisions are all that stand between you and the "vulture capitalists".

Good news for BASF

In a recent post I noted that fipronil, the active ingredient in Termidor and other products sold or licensed by BASF Corporation, was about to go off patent.  In today's article by Dan Moreland of PCT it is reported that the judge has set a July 2011 court date, effectively buying BASF some breathing room for its patent.

We'll just have to wait another year or more to see whatever big waves will take place in the termite control business when generic fipronil hits the market.

Horizontal transfer of fipronil among termites

Sometimes a scientific fact is known within the research community long before it comes out in print. This is the case with a paper published in the latest issue of the Journal of Economic Entomology.

In a paper by Bagnères et al (J. Econ. Entomol. 102(1): 347-356) the ability of fipronil to be picked up by foraging termites, both by simple contact with treated sand, and by ingestion of treated filter paper. According to one of the authors, Bob Davis of BASF Corporation, this study represented the first scientific evidence that fipronil is transferred horizontally among termite colony members.

The horizontal transfer phenomenom has been suspected for several years since it was observed that termite activity in monitoring stations consistently ceased when stations were close to fipronil-treated soil. While this doesn't mean that transfer of fipronil results in death of colonies, it does offer a possible explanation of the good track record for perimeter-only treatments for termite infested homes.

To see an abstract of the paper you can go to http://www.ingentaconnect.com/content/esa/jee/2009/00000102/00000001/art00046

Fipronil to go over and out?

The EPA is considering whether to cancel registrations for granular labels for fipronil products, according to a recent email sent this week to some Extension faculty, USDA researchers, state government officials and customers by Bayer Environmental Science representatives.

According to the email, "In 2001, EPA granted a 5-year conditional registration for broadcast granular products containing fipronil insecticide such as TopChoice® for fire ant control. Since that time, the conditional registration for these products has been extended until May, 2009. The EPA has recently indicated their intention to cancel the registration for fipronil broadcast applications when the conditional registration expires."

If so, this would mean that popular insecticides like TopChoice^® and Over N Out^® would go away, probably for good. Top Choice^® is currently the best option for control of mole crickets in the southern U.S., and both these products find use as a once-a-year treatment for fire ant control.

Although the EPA is not talking on the record about the reasons for a possible cancellation of registration, the official I spoke with noted that the agency has been concerned with the ecological impact of fipronil, especially in aquatic environments. The persistence of fipronil in the environment, and possible biomagnification in some food chains are additional issues for the agency. A review of the ecotoxicology of fipronil by Tingle et. al in 2003 will give you some idea of environmental and health concerns with this product.

Whether granular fipronil remains on the market will depend on how strong a case Bayer Environmental Science can make as well as input received from end users. As far as I can tell the registration of fipronil for termite and ant control is not currently at risk, and may never be. Fire ant baits certainly offer a strong alternative to fipronil granules for fire ant control. But turfgrass managers will miss fipronil as an option for mole cricket control.

The scientific issue at stake is what use pattern might result in fipronil toxicity issues in aquatic environments. It has been well documented that effluent from treated rice fields can impact many aquatic invertebrates and even fish (see for example Gunasekara and Troung 2007. and Stehr et. al 2006) Less well known is how much fipronil might be leaching from treated golf courses or home lawns. As a pest management specialist I would hate to lose fipronil as a tool for turfgrass management. But as an environmentalist and one who realizes the importance of water quality to our quality of life, I don't want to see pesticides eroding the health of our streams and estuaries. Let's hope the EPA uses sound science to make the right decision.