Courtship raises male fertilization success through post-mating sexual selection in a spider

Abstract

Courtship is well known for its positive effects on mating success. However, in polyandrous species, sexual selection continues to operate after copulation. Cryptic female choice is expected under unpredictable mating rates in combination with sequential mate encounters. However, there are very few accounts of the effects of courtship on cryptic female choice, and the available evidence is often correlative. Mature Argiope bruennichi females are always receptive and never attack or reject males before mating, although sexual cannibalism after mating occurs regularly. Still, males usually perform an energetic vibratory display prior to copulation. We tested the hypothesis that beneficial effects of courtship arise cryptically, during or after mating, resulting in increased paternity success under polyandry. Manipulating courtship duration experimentally, we found that males that mated without display had a reduced paternity share even though no differences in post-copulatory cannibalism or copulation duration were detected. This suggests that the paternity advantage associated with courtship arose through female-mediated processes after intromission, meeting the definition of cryptic female choice.

Males of the orb-web spider Argiope bruennichi sacrifice themselves to unrelated females

“…However, this seems unlikely because females stereotypically attack any male independently of their degree of relatedness and independently of male courtship behaviour (Schneider & Lesmono 2009). Males cling to the genital opening and can actively modulate the timing of their escape (Nessler et al 2009).…”

Dangerous mating systems: Signal complexity, signal content and neural capacity in spiders

“…Despite the intuitive nature of these predictions, there is surprisingly only little and conflicting evidence to date that directly links male traits with the vibrations that he generates. It is clear that generating vibrations is an important aspect for successful mating and fertilization (Schneider and Lesmono, 2009;Maklakov et al, 2003;Suter and Renkes, 1984); however, more recent studies that relate male traits with vibratory parameters have found surprisingly few correlations. For example, male condition did not correlate with vibratory performance (duration, rate or consistency) in A. keyserlingi (Wignall and Herberstein, 2013a).…”

Sexual Cannibalism as a Manifestation of Sexual Conflict

“…A. lobata females seem to control sperm storage, and how much they store of a given male is independent of copulation duration (Welke and Schneider 2009). Females of the congener A. bruennichi also exert control over relative paternity independently of the duration of copulation by favoring males that courted more (Schneider and Lesmono 2009). Although these studies seem straightforward examples of cryptic female choice (Eberhard 2004b), it remains to be seen whether these findings apply to many other species (see Albo et al 2013).…”

“…Because of this dramatic copulation scenario, we predicted that females of A. bruennichi would benefit from multiple mating. The potential for cryptic female choice that has been shown in the species (Schneider and Lesmono 2009) may be such a benefit. However, so far, other pronounced indirect or direct fitness benefits of multiple mating without the effect of cannibalism have not been found in this species .…”