MODULES, GINS, AND THE THREAT OF BOLL WEEVIL INTRODUCTIONS: WHAT WE KNOW SO FAR

Authors: Sappington, Thomas; Brashears, Alan; PARAJULEE, MEGHA - TX AGRIC EXP STN-LUBBOCK; CARROLL, STANLEY - TX AGRIC EXP STN-LUBBOCK; ARNOLD, MARK - TX AGRIC EXP STN-LUBBOCK; NORMAN, JOHN, JR - TX AGRIC EXT STN-WESLACO; KNUTSON, ALLEN - TX AGRIC EXT STN-DALLAS; BAKER, ROY - RETIRED (USDA-ARS-CPPRU)

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/6/2003
Publication Date: 7/1/2003
Citation: Sappington, T.W., Brashears, A.D., Parajulee, M.N., Carroll, S.C., Arnold, M.D., Norman, J.W., Knutson, A.E., Baker, R.V. 2003. Modules, gins, and the threat of boll weevil introductions: What we know so far. In: Proceedings of the Beltwide Cotton Conferences, January 6-10, 2003, Nashville, Tennessee. 2003 CDROM.

Interpretive Summary: There is concern that boll weevils may be introduced from infested areas into weevil-free areas by dispersal from transported cotton modules, by surviving inside a module and then escaping the ginning process alive, or by surviving in products of the gin such as cottonseed. Our results showed that weevils will leave the module surface as soon as possible, so most weevils will have left the module surface before being transported. However, modules will usually contain several hundreds to a few thousands of live weevils that will be fed into the cotton gin. We found that the only real chance of a live weevil escaping occurs early in the ginning process when weevils are separated from the cotton into the gin trash. There are procedures ginners can follow to reduce the risk of weevil escapes in the gin. The chances of weevil surviving in gin products such as cottonseed or baled lint are minuscule.

Technical Abstract: Experiments were conducted to determine the threat of boll weevil transport on or in cotton modules constructed in infested areas to gins in weevil-free areas. Surveys in three areas of Texas indicated that live weevils are usually present in defoliated fields just before harvest and one can expect live weevils to be packed into modules. Most weevils dispersed rapidly from untarped module surface when temperatures were warm enough for flight, but a small percentage remained at least to 24 h. Most weevils trapped on the surface under the tarp died from high temperatures. Survival of weevils inside modules was high after 1 and 3 d, but had declined dramatically by 7 d. The greatest threat of reinfestation by weevils dispersing from a module would occur when a module is constructed and transported during cool, cloudy weather, followed by warm weather favorable for flight at the gin yard. Other experiments were conducted to determine boll weevil mortality in various subprocesses in a cotton gin by introducing known numbers of weevils at various points in the system and Experiments were conducted to determine the threat of boll weevil transport on or in cotton modules constructed in infested areas to gins in weevil-free areas. Surveys in three areas of Texas indicated that live weevils are usually present in defoliated fields just before harvest and one can expect live weevils to be packed into modules. Most weevils dispersed rapidly from untarped module surface when temperatures were warm enough for flight, but a small percentage remained at least to 24 h. Most weevils trapped on the surface under the tarp died from high temperatures. Survival of weevils inside modules was high after 1 and 3 d, but had declined dramatically by 7 d. The greatest threat of reinfestation by weevils dispersing from a module would occur when a module is constructed and transported during cool, cloudy weather, followed by warm weather favorable for flight at the gin yard. Other experiments were conducted to determine boll weevil mortality in various subprocesses in a cotton gin by estimating survival. We found no evidence that weevils can survive in the seed cotton to the gin stand or beyond. The greatest threat for weevil survival and escape from the gin occurs soon after entry, with chances of survival diminishing rapidly the further the weevils progress through the different ginning processes. Small numbers of live weevils can be expected to escape into the rock trap, either as free adults or in infested bolls (Brashears et al. 2003). Thus, it is important that at-risk gins either destroy the trash collected in the rock trap immediately or collect it in a container that will not permit weevil escape. Weevils protected inside unopened bolls can escape alive with the gin trash later in the cleaning process even when passed through a high-speed trash fan. If a mechanical device can be designed and installed to slightly crack open bolls as they move to the fan, this latter problem can be mitigated to a great extent.