Mate selection strategies by male mites in the absence of intersexual selection by females: a test of six hypotheses

Abstract

Male Tetranychus urticae Koch (Acarina: Tetranychidae) search for and tend quiescent female deutonymphs, and upon emergence the tending male mates with the female. The potential for severe intrasexual selection among males, with little or no opportunity for intersexual selection on males by females, makes the T. urticae system well suited for testing hypotheses of optimal male mating behavior. We propose six hypotheses for the mate selection behavior of male T. urticae. The hypotheses can be divided in two groups: those that assume that male behavior is genetically fixed and those that assume that males vary their choice of females in response to extrinsic variables such as the number of females, number of males, or leaf condition. Our results show that males differentially tend those females that are closest to eclosion, so that an hypothesis of random mate selection must be rejected. The mate selection behavior of males is affected by the number of females present on a leaf, but not by the number of males or the leaf condition. Therefore, hypotheses of fixed mate selection behavior are rejected, as are the hypotheses of minimizing the probability of being forced to accept a cotender and mate selection based upon energetic constraints. We conclude that males use a behavioral strategy based primarily on minimization of the time invested in each copulation.