Management considerations for the brown recluse spider

The brown recluse spider (BRS), Loxosceles reclusa (Gertsch & Muliak), receives adverse publicity not only due to its common association with humans but also the medical importance of its venomous bite. BRS range include much of the south and central United States and can be found in almost all structures, from homes and sheds to woodpiles and discarded materials. Typical management techniques for the control of BRS involve the use of residual contact insecticides and/or the use of glue traps. Contact insecticides rely on BRS remaining in contact with a treated surface for a length of time to achieve control and may not provide significant BRS mortality. However, if the insecticide kills another household pest that the BRS later scavenges upon, and this results in the death of the BRS, the homeowner rids themselves of a pest and potentially reduces BRS populations. This research was initiated with the objective of evaluating how feeding on live vs. freeze-killed vs. insecticide-killed prey impacts the biological aspects of BRS measured by the feeding frequency, mortality, and weight change over an eight-week period. House crickets, Acheta domesticus (Linnaeus), used as prey were exposed to one of four treatments: water treated surface (control), spinosad or pyrethroid insecticide treated surface, or freeze-killed and fed to spiders weekly. Using a complete randomized design, 96 mature BRS were randomly assigned by sex to one of two replications of four prey treatments. BRS fed pyrethroid-killed crickets had significantly higher mortality than all other treatments.