Potential for Transport of Boll Weevils (Coleoptera: Curculionidae) to the Cotton Gin within Cotton Modules

Abstract

There is concern that cotton gins located in boll weevil, Anthonomus grandis grandisBoheman, 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 ≈100-3,700 adult boll weevils were packed inside modules constructed at the sampled fields. Marked weevils were forced through a laboratory field cleaner (bur extractor) commonly mounted on stripper-harvesters, and 14% were recovered alive in the seed cotton fraction and lived at least to 24 h. Survival of weevils placed inside modules declined over time up to 7 d, but the magnitude of the decline varied with experimental conditions. In one experiment, 91% of the weevils survived to 7 d, whereas under harsher environmental conditions, only 11% survived that long. Together, our results indicate that when cotton is harvested in an infested area, boll weevils likely will be packed alive into cotton modules, and many will still be alive by the time the module is fed into the gin, at least up to 7 d after the module's construction. KeywordsAnthonomus grandis grandis, boll weevil, cotton gin, cotton module, eradication RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. ABSTRACT 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 Þelds in three distinct areas of Texas and found that weevils can be present in large numbers in cotton Þelds 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 Ϸ100 Ð3,700 adult boll weevils were packed inside modules constructed at the sampled Þelds. Marked weevils were forced through a laboratory Þeld cleaner (bur extractor) commonly mounted on stripper-harvesters, and 14% were recovered alive in the seed cotton fraction and lived at least to 24 h. Survival of weevils placed inside modules declined over time up to 7 d, but the magnitude of the decline varied with experimental conditions. In one experiment, 91% of the weevils survived to 7 d, whereas under harsher environmental conditions, only 11% survived that long. Together, our results indicate that when cotton is harvested in an infested area, boll weevils likely will be packed alive into cotton modules, and many will still be alive by the time the module is fed into the gin, at least u...

Dispersal of Boll Weevils (Coleoptera: Curculionidae) from Cotton Modules Before Ginning

“…During peak harvest, it is common for modules to remain in the Þeld for 1 to 2 d and in the gin yard for up to a week. Sappington et al (2004d) found that live boll weevils are packed alive into cotton modules, sometimes in large numbers. Those packed on or near the surface can be considered potential dispersants.…”

“…A proportion of the total boll weevils picked up by the harvester are predicted to occur by chance on or near the surface of a module after its construction. Data from our previous survey suggested that Þve to 100 boll weevils were packed within 1 cm of the surface of the cotton modules constructed in the infested Þelds examined (Sappington et al 2004d). These represent potential dispersants at the site of construction, during transport to the gin, or after deposit of the module at the gin yard.…”

“…Modules can vary in height (commonly 2.7 m), but they have a standard width of 2.45 m and standard length of 9.75 m. Surveys in three infested regions of Texas in 2001Ð2002 revealed that boll weevils are likely to be harvested with the cotton, packed into cotton modules, and fed alive into the gin plant (Sappington et al 2004d). Extensive ginning experiments have indicated that a boll weevil entering the gin plant in seed cotton has an extremely low probability of escaping alive (Brashears et al 2002;Hughs et al 2002; SapMention 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.…”

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

“…There is concern that gins operating in areas where boll weevil populations have been eradicated or greatly suppressed may act as sites of reinfestation when serving customers who harvest cotton in a nearby area where weevil populations are still high. Sappington et al (2004a) demonstrated that adult boll weevils are commonly packed alive into modules, which are large free-standing stacks of cotton used to store the harvested cotton until the gin is ready to process it (Lalor et al 1994). In addition, stripperharvested cotton can contain many green bolls (Laird et al 1994), which are sometimes heavily infested with boll weevil larvae, pupae, and unemerged teneral adults (Sappington et al 2004a).…”

“…Sappington et al (2004a) demonstrated that adult boll weevils are commonly packed alive into modules, which are large free-standing stacks of cotton used to store the harvested cotton until the gin is ready to process it (Lalor et al 1994). In addition, stripperharvested cotton can contain many green bolls (Laird et al 1994), which are sometimes heavily infested with boll weevil larvae, pupae, and unemerged teneral adults (Sappington et al 2004a). Even picker-harvested cotton can contain a small number of green bolls (T.W.S., unpublished data).…”