Termite Bait Systems - Pros and Cons

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DELIVERING DEATH WHERE BUGS LIVE

By Mark Schleifstein

Staff writer/The Times-Picayune

June 30, 1998

Pest control companies hawk them in newspaper, television and radio ads.

Officials say they could be key to killing the immense Formosan termite

infestations in the French Quarter. Rival scientists and chemical companies

vie to proclaim theirs the best.

Widely available only in the past three years, termite bait systems are the

newest and most promising weapon in the ongoing war with Formosan termites -

and also the object of aggressive hype, sometimes wild expectations and some

unanswered questions.

The systems themselves are deceptively simple-looking. Most consist of wood

or paper in a plastic bait station.

The stations are put in the ground, where termites can find them. The

stations are checked periodically, and when termites are found, a

slow-acting poison is added to the bait. The foragers take the poison back

to the nest, where it is fed to nestmates and, in theory, the colony is

destroyed.

But these new products and the scientific debate around them are anything

but simple. Manufacturers and pest control operators are aggressively

competing for the growing market of beleaguered termite victims, and have

floated many contradictory claims about their baits' effectiveness.

Entomologists say baits can repress Formosan termite infestations. They may

even have the potential to tip the balance back toward humans in this

interspecies conflict. But given the cryptic behavior of Formosan termites,

questions remain about how well baits work, especially across an area as

densely infested as New Orleans.

''The baits are an interesting technology with tremendous potential, but

more work needs to be done on them,'' said Gold, an entomologist with

Texas A & M University, who tested an early version of bait manufactured by

Dow AgroSciences. ''And we need to be very careful when we promise or infer

their effectiveness.''

Results are encouraging

in high-profile local cases

The early evidence is positive.

The Dow Sentricon system, baited with a poison under the trade name Recruit,

for example, is credited with eliminating a 70-million-member Formosan

termite colony at the Algiers Regional Public Library. It also has

suppressed termite infestations in the Upper Pontalba Apartments, the

Cabildo and the Presbytere around Square, city and state officials

say.

A variant of the FirstLine system made by the FMC Corp. used in manholes

seems to have reduced Formosan attacks on underground telephone lines in New

Orleans.

Other new products include another baiting system called Exterra, with a

bait called Labyrinth, made by Ensystex Inc.; and Premise, a liquid

termiticide made by Bayer Corp.

Scientists running the new federal Formosan termite control program plan to

use Sentricon, FirstLine and Premise on infestations across 16 blocks in the

French Quarter, and in bait-vs.-bait tests at public schools in the New

Orleans area. The Ensystex product hasn't been yet approved by the state

Department of Agriculture and won't be used in the first year of tests.

Besides penetrating to the nest, the core of a termite colony, baits have

other advantages. They put relatively small amounts of chemicals into the

environment, and those are far less toxic than traditional barrier

treatments such as chlordane. ''If they don't hit it and go through the

space between the baits, they can eat the building without ever touching the

baits.

- RENE BOURGEOIS,

owner of Mr. B Pest Control

But the bait concept also has flaws. The main drawback is that by itself, it

won't block termites from entering a home.

''If they don't hit it and go through the space between the baits, they can

eat the building without ever touching the baits,'' said Rene Bourgeois,

owner of Mr. B Pest Control in New Orleans.

Another potential problem is the time involved. Because the baits don't

actually attract termites, it can take weeks or months for the insects to

find the baits - if they ever do - and several more weeks for the poison to

have an impact on the nest. Pest control operators can only rarely pinpoint

where Formosans are, so they leave the baits in the ground and wait for the

termites to come to them.

Because most tests have been conducted on isolated buildings, scientists

also are uncertain how well baits will work over entire infested

neighborhoods.

From a consumer and business standpoint, baits represent a quantum shift

from barrier treatments. Most baits are sold not as chemicals but as systems

that require installation and monitoring by professionals. Because baits use

only small amounts of poison, consumers end up paying more for the system

than its active ingredient.

And even though your baiting system may knock out one nest, your home could

become reinfested by termites from another nest. That means the baits and

monitoring system must remain in place as long as the termites remain a

threat.

The baits typically cost about $1,500 to $2,000 for installation and the

first year of treatment, and about $250 to $350 for annual renewals,

depending on the size of the home or business. Treatment with Premise and

traditional liquid termiticides costs about $1,000 and an annual renewal fee

of about $250. Damage guarantees, where available, may cost more.

Each treatment has its own peculiarities, which means homeowners who want to

make an educated choice will have to learn a few things about termite

behavior and pest control in general.

Promising early poison

banned on brink of release

Entomologists have been experimenting with insect baits for at least a

generation. Pesticide researchers worked on potential termite baits, notably

an insect stomach poison called Mirex, in the 1960s and 1970s.

Glen Esenther, then an entomologist at the U.S. Forest Products Laboratory

at the University of Wisconsin, is credited with turning Mirex into a

termite bait.

But in 1978, with Esenther's system ready for marketing, Mirex was banned.

Studies on laboratory animals indicated it might cause cancer in humans.

Some research into baits continued, but it wasn't until the 1988 banning of

the pesticide chlordane that entomologists and chemical companies really

pushed to find alternative termite treatments.

The challenge was to come up with a poison that killed termites without

repelling them and acted slowly enough to allow them to distribute it to

other termites in the nest.

On the market since 1995, Dow's Sentricon is based on that model. It is the

most widely advertised and commonly used termite baiting system on the

market. Many are praising its performance, including officials with the New

Orleans Mosquito and Termite Control Board and with the federal Formosan

termite program.

The active ingredient, hexaflumuron, interferes with the insect's ability to

create and shape chitin, the material that makes up the insect's outer

covering. Termites and most other insects shed their skin regularly as they

grow. Hexaflumuron short-circuits that process so the termite is unable to

molt, and is essentially strangled by its own body.

University of Florida entomologist Nan-Yao Su, who developed the prototype

for Sentricon in the 1980s, says his own tests on buildings in Louisiana and

Florida demonstrate the bait works.

''Field trials using hexaflumuron baits repeatedly demonstrated that baited

colonies of subterranean termites were suppressed to the point of

inactivity, or, at least, 'functionally' eliminated,'' Su and research

partner Rudolf Scheffrahn wrote in the paper published earlier this year.

Sentricon is marketed as a ''colony elimination system,'' though some

scientists and pest-control operators are skeptical because it's all but

impossible to observe what goes on inside an active termite nest and to know

for sure when it has been destroyed.

Su is sharing royalties with the University of Florida for his role in the

development of Sentricon, and also has had some of his research financially

supported by Dow AgroSciences. He won't say how much his share of the

royalties are.

Su said dead termites found in nests after baits were used prove that

colonies are eliminated. But he also says it really makes no difference if

an entire colony dies as long as termite activity around the home or

building drops to zero.

© 1998, The Times-Picayune. Used with permission.