Enigmatic multimodal courtship signals and mating in Schizocosa saltatrix (Hentz, 1844)

Wolf spiders (Araneae: Lycosidae) in the genus Schizocosa Chamberlin, 1904 show a diverse array of male courtship behaviors, signaling modes and morphological traits, and have been the subject of extensive study. Although S. saltatrix (Hentz, 1844) is not as well-studied as some of its congeners, this species occupies a phylogenetic position basal to the well-studied ocreata clade within the genus. Here, we present a detailed analyses of its courtship and provide some insights about multimodal signals in the genus Schizocosa. Male and female S. saltatrix were collected from the field and raised to maturity in the lab, then paired randomly for mating trials, in which courtship and mating behaviors were recorded. Male courtship displays consist of vibratory signals coupled with leg-raising visual signals, suggesting that males apparently use complex (multimodal) signals in courtship despite assumptions from other studies. While the overall amplitude of vibratory signals is not related to mating success, rates and amplitude of some individual components (leg strikes) appear to play a role. Female responses show that variation in visual and vibratory signals is associated with receptivity and mating success, although signal information content (e.g., body condition) is unclear. Although visual displays may serve as attention-altering signals and attract female attention, vibratory signals are more important to receptivity. Recent phylogenies suggest that while leg decorations, extensive leg pigmentation and visual signals have likely been secondarily lost, visual displays are retained in S. saltatrix, perhaps as attention-altering signals.