DISTURBANCE BEHAVIORS IN THE SPIDER ULOBORUS-GLOMOSUS (ARANEAE, ULOBORIDAE) - POSSIBLE PREDATOR AVOIDANCE STRATEGIES

When disturbed, U. glomosus remain in position at the hub of their orb webs, jump from the web, move to the edge of the web, or shake the web. Juveniles more frequently exhibited moving and jumping responses; most adults jumped from the web or remained in position. Adults with linear stabilimenta tended to shake their webs in the morning and to jump from their webs in the event. Juveniles with linear stabilimenta shook their web during all times of day. Adult females with egg-sac chains were usually aligned with the egg sacs and tended to remain in position when disturbed. Both adults and juveniles lacking stabilimenta or egg-sac chains tended to jump from their webs or move to the edge of their webs. Predatory wasps repeatedly flew near the spiders without eliciting a response. Data agree with the hypothesis that moving to the edge of, shaking, and jumping from the web may be predator avoidance strategies elicited by direct contact. -from Authors