Researchers fight boll weevil reinfestation

Texas eradication programs make problem more urgent WITH BOLL weevil eradication proceeding in patchwork-quilt fashion across Texas, concerned cotton officials are moving to see that weevil-free areas don't become reinfested, including from highly mobile harvesting and seedcotton transportation equipment or gins.

Texas, with 4.5 million acres of cotton and its long harvest season, has more harvesting and transport equipment plying its highways in and out of different eradication zones than any place in the U.S.. Cotton Belt. Also, some gins handle seedcotton from both eradicated and non-eradicated areas, sometimes from the same grower/customer.

The goal of the current effort is to establish, if needed, a "workable but least stringent" protocol for gins and the earlier field-to-gin movement of cotton to help protect against any boll weevil reinfestation. It is a way to guard the investment farmers already have paid into the weevil eradication program with per-acre assessments.

The Texas Department of Agriculture is drafting a set of rules and guidelines to reduce the threat of weevil reinfestation. The Texas Boll Weevil Eradication Foundation, Inc., the Texas Cotton Ginners Association, Texas Cotton Producers, and Texas A&M University will review and approve any new operating guidelines that would become a part of the state's official pest eradication program.

Meanwhile, the USDA-Agricultural Research Service is initiating several new studies relating to boll weevil survival in cotton gins. Information into the survival or kill of the weevil in the ginning and bale packaging process is lacking.

"Our preliminary studies, for example," says Roy V. Baker, research leader, USDA-ARS, Cotton Ginning Laboratory in Lubbock, "suggests that fan speeds in gins that are known to eliminate the pink bollworm (PBW) also kill the boll weevil." That is encouraging news since more is known about eliminating the PBW in the ginning process than is known about eliminating weevils.

Another evaluation currently under way at Baker's Lubbock lab has found that 100 percent of boll weevils are wiped out when cotton is compressed in a universal-density bale press. A Texas Rio Grande Valley-based scientist, Tom Sappington, USDA-ARS, Wes-laco, Texas, who is working with Baker, captured and marked boll weevils for the recent test. Their planned joint two-year project is entitled "The Impact of Various Harvesting, Seedcotton Handling, and Ginning Practices on Boll Weevil Survival."

Some unique problems arise for ginners located in and near eradication zones, Baker noted. He, too, wonders if certain gins can continue to service their usual customers without being a source of reinfestation into weevil-suppressed or weevil-free zones.

Involved are several levels of boll weevil infestation under the national program to eliminate the boll weevil as an economic pest of cotton, namely whether a zone is in a "suppressed," "functionally eradicated," "eradicated" or infested status. "Techniques for treating, handling and moving infested trailers or modules of seedcotton need to be developed," Baker adds, saying these are goals of the new project. "In addition, a cotton gin operating procedure should be devised and verified for the ginning of infested cotton. It's imperative that only weevil-free products leave the gin, and that weevils do not escape the gin during processing."

A post-doctoral entomologist familiar with the boll weevil life cycle will be added to the Lubbock ginning lab location early next year. He will work closely with Baker, one of the nation's leaders in cotton gin operation.

The planned research effort will involve the following specific activities:

- Determine the magnitude of weevil presence in and on cotton modules prior to and after transport to the gin.

- Investigate various techniques for managing unharvested cotton and modules of harvested cotton in the field prior to transport to reduce or eliminate weevils in the seedcotton.

- Evaluate suitable protective covering and hauling methods.

- Evaluate the gin's various sub-processes, including cleaning, drying, ginning, lint cleaning, pressing and waste handling, to determine the mortality of adult weevils, pupae and larvae.

- Develop gin-equipment specifications and operating procedures that ensure that any weevils brought to the gin are killed during processing.

- Devise a gin site monitoring strategy for verification of compliance.

The initial evaluation of fan speed on weevil survival has been completed, and the evaluation of the bale press effect on weevil survival is still in progress.

Baker estimates that most module trips to the gin are in the 25 to 30 mile range. Still, that's far enough to cross zone lines.

"We have recently come to realize that we don't know a whole lot about what happens to the weevil at the gin as to its survival or mortality rate. We need to know a lot more about it. We've got to help producers protect their investment in this extensive and necessary program."

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