Dispersal of Boll Weevils (Coleoptera: Curculionidae) from Cotton Modules Before Ginning
Journal of Economic Entomology
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. MarkÐrelease-recapture experiments in August and September in Texas indicated that most weevils disperse rapidly from the module surface, temperature permitting, unless conÞned under a module tarp, where most died. Nevertheless, 1Ð5% of released weevils were recovered alive after 24 h on the
... ter 24 h on the side and top surfaces of modules, representing potential dispersants. Mortality of boll weevils caged on the top surface of a module was 95Ð100% after 1Ð 4 d when maximum air temperatures were Ն33ЊC and 72Ð100% when minimum temperatures were Ϫ7ЊC or lower, but a few survived even after experiencing a minimum daily temperature of Ϫ12ЊC. Under warm (daily maximum temperatures Ն25ЊC) and cold (daily minimum temperatures Յ0ЊC) weather conditions, survival was higher under the tarp than on the open surface of the module (20 versus 7% and 42 versus 26%, respectively), but mortality was 100% in both locations when temperatures reached 34ЊC. Our results indicate that although the threat to an eradication zone posed by boll weevil dispersal from an infested module is very low under most environmental conditions, it is probably greatest when 1) a module is constructed and transported from an infested zone during weather too cool for ßight, followed by warm weather favorable for ßight at the gin yard; or 2) such a module is transported immediately after construction in moderate-to-warm weather.