Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2004
Publication Date: 6/1/2004
Citation: Sappington, T.W., Brashears, A.D., Parajulee, M.N., Carroll, S.C., Arnold, M.D., Norman, J.W., Knutson, A.E. 2004. Potential for transport of boll weevils (coleoptera: curculionidae) to the cotton gin within cotton modules. Journal of Economic Entomology. 97(3):934-940. Interpretive Summary: The boll weevil is a major pest of cotton, and great efforts are underway to eradicate it from the U.S. There is concern that weevils may be transported inside modules of harvested cotton to cotton gins from neighboring areas that are still heavily infested. We found that it is indeed common for large numbers of boll weevils to be picked up by the harvester and packed alive into the cotton module. If the cotton is processed by a field cleaner during harvest, a high percentage of weevils will be dropped back to the ground or killed, but some will still make it alive into the module. A module may sit in the field or the gin yard for several days waiting for its turn to be ginned. We found that many weevils can survive inside the module for at least 7 days. Whether weevils can survive once they are fed into a gin is the subject of other studies. These results demonstrate that live weevils are likely to be delivered to the gin with the modules, and provide regulatory agencies with information necessary to design appropriate guidelines for transport of modules across eradication zone boundaries.
Technical Abstract: There is concern that cotton gins located in boll weevil (Anthonomus 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 - 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 to 24 h. Survival of weevils placed inside modules declined over time up to 7 days, but the magnitude of the decline varied with experimental conditions. In one experiment, 91% of the weevils survived to 7 days, whereas under harsher environmental conditions, only 11% survived that long. Taken 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 days after the module's construction.