|Norman, John, jr|
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/9/2002
Publication Date: 7/1/2002
Citation: Sappington, T.W., Brashears, A.D., Baker, R.V., Carroll, S.C., Arnold, M.D., Parajulee, M.N., Norman, J.W., Knutson, A.E. 2002. Potential for boll weevil transport to gins on modules. In: Proceedings of the Beltwide Cotton Conferences, January 9-13, 2002, Atlanta, Georgia. 2002 CDROM. Interpretive Summary: Boll weevils are being eradicated from several zones in Texas, but weevils may be reintroduced into suppressed zones by traveling from infested areas on harvested cotton modules. We conducted experiments in three parts of Texas to determine the potential for boll weevils to travel to cotton gins in or on cotton modules. Significant numbers of weevils were found in defoliated cotton during harvest, and some of these will make it alive int or on the surface of modules. Experiments in which marked weevils were released on module surfaces showed that most weevils leave the surface if it is warm enough to fly. Most of those under the module tarp die if temperatures are high, but some burrow into the cotton and may make it alive to the gin yard.
Technical Abstract: Because of the cost and difficulty involved in eradicating the boll weevil (Anthonomus grandis) from designated zones, the threat of reintroduction and reinfestation is always of concern. We began a series of experiments designed to determine the potential for boll weevil transport on or in cotton modules to the gin yard. Surveys indicated that there can be substantial numbers of adult weevils present in defoliated cotton just prior to harvest. Estimates of weevils per module in three different regions of Texas ranged from 203 to 3,750, and weevils calculated to be on the surface ranged from 3 to 52. Mark-release experiments indicated that most weevils disperse from the release sites if temperatures are warm enough -- by flight if not under a tarp, by walking and burrowing if under a tarp on top of the module. Most weevils died under the tarp when temperatures were high, but some were unaccounted for and may have escaped lethal temperatures by burrowing into the loose cotton on top of the module. Overall, our results indicate that one can expect at least a small number of weevils to make it to the gin alive inside a module depending on the starting population of weevils in the defoliated cotton. The percentage of weevils remaining on the surface of a module from the time of its construction can be expected to decrease the longer the module remains in the field, especially with high (>80 degrees F) temperatures, because of the observed high propensity of weevils to disperse from modules by flight.