Dispersal of boll weevils (Coleoptera: Curculionidae) from cotton modules before ginning.

We characterized the level of risk of boll weevil, Anthonomus grandis grandis Boheman, reintroduction to an eradication zone posed by dispersal from cotton modules during and after transport to the gin. Mark-release-recapture experiments in August and September in Texas indicated that most weevils disperse rapidly from the module surface, temperature permitting, unless confined under a module tarp, where most died. Nevertheless, 1-5% of released weevils were recovered alive after 24 h on the side and top surfaces of modules, representing potential dispersants.

Potential for escape of live boll weevils (Coleoptera: Curculionidae) into cottonseed, motes, and cleaned lint at the cotton gin.

Reintroductions of the boll weevil, Anthonomus grandis grandis Boheman, into areas of the United States where it has been eradicated or suppressed are very expensive to mitigate. There is concern that a cotton gin in an eradication zone may serve as a site of boll weevil reintroductions when processing cotton harvested in a neighboring infested zone. Similarly, there is a question whether weevil-free areas can safely import gin products, such as cottonseed and baled lint, from infested areas without risking an introduction.

Boll weevil (Coleoptera: Curculionidae) survival through cotton gin trash fans.

There is concern that cotton gins may serve as loci for reintroduction of boll weevils, Anthonomus grandis grandis Boheman, to eradicated or suppressed zones when processing weevil-infested cotton from neighboring zones. Previous work has shown that virtually all weevils entering the gin in the seed cotton will be removed before they reach the gin stand. Those not killed by the seed cotton cleaning machinery will be shunted alive into the trash fraction, which passes through a centrifugal trash fan before exiting the gin.

Boll weevil (Coleoptera: Curculionidae) survival through the seed cotton cleaning process in the cotton gin.

There is concern that gins located in boll weevil, Anthonomus grandis grandis Boheman, eradication zones may become points of reintroduction when they process cotton grown in a neighboring infested area. We estimated boll weevil survival through two typical machine sequences used in commercial cotton gins to clean and dry the seed cotton in advance of the gin stand, as well as separately through two incline cylinder cleaners or one or two tower dryers operating at different temperatures. Large numbers of laboratory-reared adult boll weevils were marked with fluorescent powder, fed into the test system, and recovered with the assistance of blacklights.

Potential for transport of boll weevils (Coleoptera: Curculionidae) to the cotton gin within cotton modules.

There is concern that cotton gins located in boll weevil, Anthonomus grandis grandis Boheman, eradication zones serving customers in adjacent infested zones may serve as a site for boll weevil reintroductions if weevils are transported alive inside cotton modules. We surveyed fields in three distinct areas of Texas and found that weevils can be present in large numbers in cotton fields that have been defoliated and desiccated in preparation for harvest, both as free adults and as immatures inside unopened bolls. Harvested cotton taken from module builders indicated that approximately = 100-3700 adult boll weevils were packed inside modules constructed at the sampled fields.