Finding a Weevil in a Haystack?

Adult boll weevils, Anthonomus grandis Boheman, ranging in numbers from 6 to 82, were caught in pheromone traps that were placed upwind of, and adjacent to, six different large round hay bale-storage sites located in the north-central portion of the cotton-growing area of Uvalde County, Texas.  Traps were installed beginning 20 March, 2009 and maintained until 31 August, 2009.  When time schedules permitted, the traps were checked weekly and pheromone strips and kill strips were added or changed at appropriate intervals.  Trap catch numbers spiked following significant rainfall events or in traps adjacent to those sites where bales were removed.  Weevil numbers in traps adjacent to hay bale-storage sites were compared to those of the closest Texas Boll Weevil Eradication Foundation’s trap.  With one exception, many more weevils were trapped in those traps adjacent to the hay bale-storage sites than in the Foundation’s traps.  For the exception, the "Foundation’s" trap was positioned where the pheromone plume from the trap would have been carried almost directly toward the hay bale-storage site.  These data suggest an association of the weevils with large round hay bales; additional, planned work should help to determine if the weevils are using the hay bales as refuge sites.