ABSTRACT

Experiments were conducted to determine the potential 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 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.