PARASITES.
The eggs in the cocoon are very liable to be eaten by parasitic insects. Certain wingless Hymenoptera are always hunting around in the neighborhood of spiders’ nests, and may sometimes be seen trying to stick their ovipositor through a cocoon. If they succeed, their eggs hatch before the spiders, and eat the latter up. Other parasites lay eggs on the backs of young spiders, and the larva lives attached to the outside till it gets nearly as large as the spider itself.