Meeting Abstract
Nuptial gifts are material donations given before or during copulation from male to female; gifts exist predominantly in the form of prey or other food items, or secretions from male glands. The “Candymaker” hypothesis as described by Warwick in 1999 states that males may include phagostimulants to work as sensory traps in their glandular nuptial gift offerings in order to exploit the female’s gustatory response and gain a fitness advantage that may conflict with the female’s reproductive interests. Despite their description in multiple suborders, the nuptial gift secretions of harvestmen (Opiliones) have never been analyzed for chemical content. In this study, samples from five different species (L. ventricosum, L. politum, L. vittatum, L. calcar, and L. aldrichi) representing the major Leiobunum lineages will be compared. Both mating behavior and male genital morphology vary between the species in this group, making this an intriguing system for comparisons across taxa. Specimens were collected at the Katharine Ordway Field Station in Inver Grove Heights, MN; with additional material loaned by the Minnesota Insect Collection. Nuptial gift issued from the penile alae and accessory glands was extracted and free amino acid profiles were compared to an amino acid standard using high-performance liquid chromatography (HPLC). Preliminary data suggest that harvestmen nuptial secretions contain free amino acids that could act as phagostimulants. This study contributes to the knowledge of harvestmen, an under-studied group of animals, as well as to our understanding of the biological role, constitutional variety, and chemical ecology of nuptial gifts.
