Boll Weevil (Coleoptera: Curculionidae) Survival Through the Seed Cotton Cleaning Process in the Cotton Gin

Boll Weevil (Coleoptera: Curculionidae) Survival through Cotton Gin Trash Fans

“…The 95% upper conÞdence level (p u ) calculated for the observed zero rate of survival to 24 h of the total of 2,100 boll weevils tested at the 56.2 m/s fan-tip speed is 0.00143, or 0.143%. This represents the statistical worst case for potential boll weevil survival based on sample size alone at the lowest fan speed tested (Couey and Chew 1986, Venette et al 2002, Sappington et al 2004b). Because increasing fan-tip speed treatments provided progressively harsher conditions, the sample sizes for the lower speeds tested can be pooled for calculating the 95% upper conÞdence levels of the greater fan speeds.…”

“…In conclusion, previous work has shown that modern seed cotton cleaning machinery in the gin is very good at removing boll weevil adults before they reach the gin stand (Sappington et al 2004b). Any weevils removed with the trash that are not killed directly by the cleaning equipment represent potential dispersants that could reinfest an eradication zone, unless they are killed by a trash fan as they exit the gin.…”

“…Even picker-harvested cotton can contain a small number of green bolls (T.W.S., unpublished data). Most, perhaps all, weevils entering the gin either as free adults or as immatures in various stages of development inside infested bolls will be removed or killed by seed cotton cleaning machinery before reaching the gin stand (Sappington et al 2004b). Although many weevils are Mention of trade names or commercial products in this article is solely for the purpose of providing speciÞc information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.…”

Potential for Escape of Live Boll Weevils (Coleoptera: Curculionidae) into Cottonseed, Motes, and Cleaned Lint at the Cotton Gin

“…The capsules were intended to simulate a boll weevil pupal cell, a brittle chamber of tightly packed larval frass in which the adult ecloses from the pupa. Pupal cells containing teneral adults have been found packed inside cotton modules (Sappington et al 2004b), and they are about the size and shape of cottonseeds, so it is conceivable they might survive to the gin stand and be separated into the seed fraction. It was impossible to collect large numbers of natural pupal cells, so we tested encapuslated adult weevils instead.…”

“…In markÐrecovery experiments, we have quantiÞed survival potential of boll weevils passed through seed cotton precleaning machinery, dryers operating at different temperatures, and trash fans operated at different fan-tip speeds (Sappington et al 2004b, c).…”