Love is in the air: olfaction-based mate-odour identification by jumping spiders from the genus Cyrba

Jumping spiders (Salticidae) are known for having good eyesight, but the extent to which they rely on olfaction is poorly understood. Here we demonstrate for the first time that olfactory pheromones are used by two species from the salticid genus Cyrba ( C. algerina and C. ocellata ). Using a Y-shape olfactometer, we investigated the ability of adult males and females of both species to discriminate between mate and non-mate odour. A hidden spider or a spider’s draglines (no spider present) were used as odour sources. There was no evident response by females of either Cyrba species to any tested odour. Males of both species chose odour from conspecific females, or their draglines, significantly more often than the no-odour control, but there was no evident response by males to any of the other odours (conspecific male and heterospecific female). Our findings demonstrate that C. algerina and C. ocellata males can make sex- and species-specific discriminations even when restricted to using olfaction alone. Also, by showing that draglines can be a source of olfactory pheromones, our findings illustrate the difficulty of ruling out olfaction when attempting to test for chemotactile cues.