SEXUAL BEHAVIOR AND ITS APPLICATION TO A SPECIES PROBLEM IN THE SPIDER GENUS PHILODROMUS (ARANEAE: THOMISIDAE)

Abstract

The mating behavior of Philodromus rufus Walckenaer at Kentville, Nova Scotia, and Belleville, Ontario, indicates that the population is composed of two sympatric forms, one in which the males vibrate their legs on approaching the female, the other in which the males do not vibrate. Males of both forms respond to the sex scents of females of both, and fertility of crosses between the forms is as high as it is within each form. Less than 50% of attempted crosses are successful, however, and the vibrating form is more successful at crossing than the other. On this and other evidence the forms are diagnosed as two closely related species, one of which has not previously been described.