Scholarly Commons

Octopamine effects on wolf spider courtship and mating interactions: more sex or more cannibalism?

Octopamine (OA) has been used in development insecticide for crop pests, but the impact of these compounds has been poorly studied among non-target species like spiders. Wolf spiders are an important biocontrol agent in agricultural systems. Studies have shown that male wolf spiders with elevated endogenous levels of OA use more coercive mating tactics compared to low-OA males. We compared the effect of octopamine on the courtship behavior between males and females of the wolf spider Pardosa milvina. We dehydrated male and female spiders prior to dosing with a 2 mg/1 ml concentration of OA : water solution among random pairs of unmated spiders in four different treatment groups. A fifth treatment group was not withheld water to control for dehydration. We measured male courtship, female receptivity, aggression and sexual cannibalism across groups. Results suggest that OA significantly decreases male courtship but does not significantly affect females.