The black widow spider, Latrodectus hersperus, has recently been identified as a pest of table grapes in California due to its unwanted presence in grape clusters. We examined the lethal effects of two acaricides, and five insecticides currently registered in the production of table grapes for their potential to be used as a treatment for the control of black widow spiders. In direct spray exposure, only the insecticides Methomyl (Lannate), Chlorpyrifos (Lorsban), and Fenpropathrin (Danitol) provided excellent male and female black widow control within a day. Under indirect exposure on treated bark, only Chlorpyrifos and Fenpropathrin provided 100% black widow control 10 days after treatment. To further evaluate the level of toxicity of the three successful chemicals, the pesticides were tested on three different developmental stages of the black widow spider. Methomyl was the most toxic to adult black widows producing an LD50 at 2.5% of the label rate. Fenpropathrin produced LD50 values at 9.5% and 0.85% of the label rate for immature and spiderling stages respectively, making it the most toxic chemical for the immature stages. Chlorpyrifos was moderately toxic relative to the other two chemicals providing LD50 values at 5.3% and 16.4% of the label rate for adult and immature stages respectively. Lorsban was the least toxic to the spiderling stage as spiderlings seemed unaffected at even the highest rates. The immature stage appeared to be the most resistant to chemical applications as LD50 values were highest at this stage in all three chemical trials.