Spider

There are over 35,000 species of spiders worldwide, with about 3,000 occurring in North America. Many species of spiders are household pests. Wherever their food is available, spiders are likely to be found. All spiders are predators, feeding mainly on insects and other small arthropods. In the United States only two spider groups are considered dangerous to man, the black widow spiders and brown recluse spiders. Both of these groups are composed of several species.

Since the black widow and brown recluse spider groups are of primary importance in human environments, their identification is essential. For both groups, several species are involved which can only be separated by experts. However, group recognition alone is sufficient for PCO purposes.

Female spiders usually do not eat their mate after copulation. In a week or more after mating, the female deposits as few as 20-30 to several hundred eggs in a silken sac. Depending on the species, one or more sacs may be made. Species which tend their egg sacs or young usually produce fewer eggs. It may be weeks later, or not until the following spring, before the spiderlings hatch and/or emer e from the sac.