The Lower Rio Grande Valley remains the last bastion of boll weevil infestation in the country, and the decades-old eradication program continues to deplete the pest’s numbers there, but as long as a viable population exists, cotton farmers cannot rest.

“In 1892, the boll weevil entered the United States,” says Larry Smith, Texas Boll Weevil Eradication Foundation program coordinator. “It took just 29 years to get to the Virginia coast and people did not move around as they do today. That’s why we must cut off weevils in the Valley.”

Smith, speaking at the recent Blackland Income Growth (BIG) Conference in Waco, said the rest of the state is in good shape, with weevil numbers ranging from about 40 to zero. But some of those trap catches result from “hitchhikers” moving out of the Valley. “That’s why we continue trapping,” he said.

(Meanwhile, the entire cotton industry is tuned into the situation for fear the pest could re-infest other areas that are currently weevil-free. To read more, see Boll weevil-free status must be guarded to prevent re-infestation).

 “We have a corridor of weevil movement in the Valley. We will continue to struggle with that until we get a handle on boll weevils coming out of Mexico.”

Eradication efforts in Mexico have gone backwards the past few years. “In 2004, Mexico averaged more than 40 weevils per trap per week,” Smith said. “That number dropped a lot, but has built back up since 2009.”

Several issues complicate eradication efforts along the border. “We have 4,000 acres of cotton between the fence and the river,” he said. That hinders control efforts.

“We are getting reproduction from cotton in Mexico. “With even a few plants left in a field we get weevil reproduction. We have to get rid of every plant.

“We’ve had a lot of issues with the fence, but the 4,793 acres of cotton in Mexico is the biggest problem in the LRGV.” Weevil numbers on that acreage are increasing.

“In 2009, Mexico had no cotton,” Smith said. “They had been bringing weevil numbers down, but after 2009, numbers went back up.”

Most of the weevils caught in the LRGV are caught along the river. “A lot of the northern area has reduced weevil numbers.” When the eradication program first started in the LRGV, weevil numbers topped 3 million. That’s now down to less than 300,000.

Also, wind turbines make aerial application and eradication difficult in the Valley.