Copulatory dialogue: female spiders sing to influence male genitalic movements.

PERETTI, A. V., EBERHARD, W. G. & R. D. BRICEÑO

Sitges-Barcelona, España.

Congreso; 23 European Colloquium of Arachnology; 2006

European Arachnological Society

Female behavior during copulation that could function as communication with the male is probably more common than previously appreciated, but its functional significance remains little studied. Stridulation during copulation by the female of the spider Physocylus globosus (Taczanowski, 1873), documented here for the first time, is common and non-coercive, thus permitting simple tests regarding its possible function. Males squeezed females rhythmically with their enlarged, powerful genitalia throughout copulation, and greater numbers of male genitalic squeezes were associated with increased paternity when females mated with two males. Contextual associations suggest that female stridulation represents attempts to induce the male to interrupt genitalic squeezes: female stridulation was more common when the male was squeezing her; females were more likely to stridulate when individual male squeezes were longer, and when the male had not responded to a previous stridulation by loosening a squeeze; females were more likely to refrain from stridulating when the male loosened a squeeze; males were more likely to loosen squeezes when the female stridulated; and female stridulation was associated with rejection of males in other contexts. Males that responded to female stridulation more consistently by loosening their squeezes obtained greater paternity. Future studies should include the heretofore neglected possibility that female behavior during copulation functions to signal to the male.