Chemical and visual ecology of the Symphyta

Abstract

The Symphyta is the most basal sub-order of the Hymenoptera and includes the woodwasps, horntails and sawflies, many of which are pests. Adults are generally short-lived and as a result males and females experience strong selection to rapidly find a mate and females to find oviposition sites. Mate-searching typically relies on visual and olfactory stimuli such as sexually dimorphic morphology (i.e., body parts used in signalling) and pheromones. Here we review the available literature on the chemical and visual ecology of the Symphyta with potential for use in survey and detection programmes. Stimuli reviewed include but are not limited to sex pheromones, larval defensive compounds, plant kairomones and colour preferences. Sex pheromones are known for 19 species of Symphyta and show shared evolutionary patterns in chemistry, production site and ecological role. In general, sex pheromones in the Symphyta are female-produced, oxidized cuticular hydrocarbons and yellow traps capture more individuals than other colours, although exceptions do exist. More work is needed to expand on these and identify new patterns in the visual and chemical ecology of the Symphyta.