SEASONAL DISTRIBUTION OF BOLL WEEVILS, ANTHONOMUS GRANDIS, CAPTUREDIN PHEROMONE TRAPS NEAR COTTON AND UNCULTIVATED HABITATS IN CENTRAL TEXAS

摘要

Boll weevil eradication programs in the U.S. rely heavily on trap captures of boll weevils to determine the need forinsecticide applications. However, currently available information regarding the interpretation of trap captures andparameters influencing the optimal design of trapping systems is incomplete. A field study was initiated in the Brazos Valleyof Texas during the spring of 2000 to examine several dynamic facets of boll weevil trap captures. An objective of this studyaddressed herein was to examine the influence of trap distance from cotton on the seasonal distribution of boll weevilcaptures. Overall, weevil captures by traps > 1000 m from cotton were less than by traps closer to cotton. Trap captureswere highest during the cotton harvest period at all trap distances, but seasonal patterns corresponding to other agronomicperiods varied among trap distance classes. Seasonal patterns in captures also differed between years of the study, primarilybecause of depressed trap captures during the harvest period of 2001, which likely resulted from ULV malathion applicationsby the Texas Boll Weevil Eradication Foundation during the first-year diapause phase in this region. Of particular interest,the characteristic depression of trap captures associated with the squaring and early-bloom period in cotton was less evidentfor traps located between 100 and 1000 m from cotton than for traps located within 100 m of cotton. These results provideadditional insight into the spatial dynamics of boll weevil trapping that may result in improved monitoring systems foreradication efforts.