Male induction of female quiescence/catalepsis during courtship in the spider, Agelenopsis aperta.

We investigated the mechanism by which courting males of the desert spider, Agelenopsis aperta, induce a quiescent state in females. We experimentally induced quiescence in two ways. First, we suspended courting males below females who were housed within netted isolation chambers. Second, we exposed females to air passed over a homogenate of male tissue. Both treatments induced a quiescent state in test females, supporting the hypothesis that an airborne chemical emitted by males elicits female quiescence. Additional tests involving the female isolation chamber indicated that this molecule has an effective range of about 3 cm, and that male drumming of the palpal appendages during courtship may direct the pheromone plume towards the female. [ABSTRACT FROM AUTHOR]