To Mate or to Steal Food? A Male Spider’s Dilemma

Abstract

We report a sequence of unusual male behaviors observed in Nephila pilipes (Fabricius, 1793) (Araneae: Nephilidae Simon, 1894), a sexually size dimorphic tropical spider species in Singapore. We documented a male suitor using his mouth parts (chelicerae) rather than his copulatory organs (pedipalps) to repeatedly probe female genitals. The behaviors may have served as a strategy to assess the female’s mating status, functioned as a courtship strategy, or, most plausibly, represented an attempt to remove a genital plug. The documented chrono-sequence culminated in the male’s attempted commensalism, followed by an aggressive attack by the female, resulting in near-fatal injury to the male. Notably, the attack did not escalate into cannibalism, suggesting that the extreme size difference in Nephila may render small males unappealing as prey.