Showing papers by "Ally R. Harari published in 2008"
TL;DR: The results support the hypothesis that sexual cannibalism is a male strategy in this species and support the existence of somersault behavior, which was previously known only from the redback spider, Latrodectus hasselti.
Abstract: Sexual cannibalism may represent an extreme form of male monogamy. According to this view, males gain reproductive success by sacrificing themselves to females. We studied the occurrence and timing of sexual cannibalism in the brown widow spider Latrodectus geometricus and compared male courtship and mating behavior with virgin and with previously mated females. We found that events of sexual cannibalism are frequent, that they occur during copulation and that males initiate cannibalism by placing the abdomen in front of the female’s mouth-parts during copulation (somersault behavior). Both the somersaults and mating occurred more frequently with virgins than with previously mated females. Our results support the hypothesis that sexual cannibalism is a male strategy in this species. The somersault behavior was previously known only from the redback spider, Latrodectus hasselti. It is as yet unknown whether self-sacrifice has evolved more than once in this genus.
49 citations
TL;DR: It was found that damage to the male organ was frequent but did not necessarily result in male sterility, suggesting the possibility that the tip of the embolus functions as a partial mating plug.
Abstract: Copulatory organ breakage, in which a portion of the male's genitalia breaks off and remains in or attached to the female's genitalia may represent a male strategy of high investment in a single mating. Such a strategy is expected when mating opportunities for males are limited and competition for females is high. We studied costs and benefits for males as a consequence of male organ breakage in the white widow spider (Latrodectus pallidus O. Pickard-Cambridge 1872). In order to estimate the frequency and consequences of such damage we provided each male with four virgin females simultaneously in an outdoors enclosure. We recorded male mating success and loss of the tip of the embolus (the male intromittent organ) inside the female's genitalia for each male. In order to test the effect of the broken tip as a mating plug, we collected females from natural populations and observed the location of embolus tips inside their genitalia. We found that damage to the male organ was frequent but did not necessarily result in male sterility. From the field data, we found that the likelihood of a second embolus tip entering the spermatheca is significantly lower than that of the first tip, suggesting the possibility that the tip functions as a partial mating plug.
11 citations