Spiders are a common component of any ecosystem and it is usually recognized that their predatory habits are a benefit to the balance of arthropods in their environment. Employing pesticides that are harmless to spiders could increase the effectiveness of natural predation, thereby reducing the number of pesticide applications, lowering production costs and reducing environmental pollution in crop systems. The document outlines procedures for testing the susceptibility of spiders to Microbial Pest Control Agents (MPCA's). With over 30,000 species they feed almost exclusively on insects. Given what appears to be a greater overall abundance across the continental U.S., Oxyopes scalaris is the organism selected as a test species for this protocol. Six methods are described for testing Contact Toxicity and Oral Toxicity of test MPCA's.