Boll Weevils Find Winter Habitat in Urban Backyards

Date:  Aug. 5, 1997
Editor: D'Lyn Ford  (505) 646-6528, dlford@nmsu.edu

LAS CRUCES -- City homes located near cotton fields can provide a breeding ground for boll weevils in the winter, a New Mexico State University study shows.

"Boll weevils don't spent the winter in cotton fields," said Jane Pierce, entomologist with NMSU's Agricultural Science Center at Artesia. "They look for areas that have good insulation like leaf litter."

Although places like Carlsbad don't have much leaf litter, overwintering boll weevils have been found underneath shingles and in buildings, gardens, overgrown weedy areas and grass clipping piles, she said.

Boll weevils have become more difficult to control as they spread across the state, Pierce said. Even a few boll weevils can have a surprising impact. One weevil in the spring could be responsible for a trillion by Aug..

Insects only travel about a mile to reach a cotton field in the spring, but can migrate 30 to 60 miles in the fall, she said.

"In the fall, they're in migratory mode," Pierce said. "They've stored more fat and have more energy."

Information from the study could help farmers decide the best place to plant cotton and help reduce boll weevil infestations, she said. Also, research planned for next year on the weevil's survival rate in different habitats and weather conditions may offer insight into the problem.

"We have an established population in Lea County, and we're seeing economic damage as a result of those boll weevils," Pierce said. "The referendum effort in Lea County failed. So, we're just looking at voluntary control efforts by farmers."

This is the first year that significant numbers of boll weevils have been picked up in the Pecos Valley, she said. Insects also have infested the Mesilla Valley.

"One of the better controls in the Mesilla Valley would be if people didn't grow cotton near Las Cruces," Pierce said. "Like Carlsbad, a big problem in the Las Cruces area is that little patches of cotton are scattered all over the place. You can't really treat a lot of those areas with an insecticide."

Overall, New Mexico cotton growers may not see much of an economic impact from boll weevil damage this year, but next year they might not be as lucky, she said.