SEXUAL COHABITATION AS MATE-GUARDING IN THE LEAF-CURLING SPIDER PHONOGNATHA-GRAEFFEI KEYSERLING (ARANEOIDEA, ARANEAE)

The leaf-curling spider Phonognatha graeffei incorporates a twisted le af into the central hub of its orb-web that is used as a retreat. This species is unusual among orb-weaving spiders because males cohabit in the leaf retreat with both immature and mature females, mating with t he former shortly after the female molts. Cohabitation appears to be a form of mate-guarding because cohabiting males respond agonistically to rival males that venture onto the web, and their behaviour depends upon the reproductive status of the female; males defending immature f emales are more aggressive than those defending virgin, adult females. Males copulate with previously mated females for significantly longer than with virgin females. Females may cannibalise cohabiting males, w hich occurs independently of whether the female has been deprived of f ood. Females that cannibalise a single male do not have a higher fecun dity than non-cannibalistic females.