Experimental evidence for a female sex pheromone in Arrenurus manubriator (Acari: Hydrachnida; Arrenuridae).

We present experimental evidence for a water-borne female-produced sex pheromone in aquatic parasitengonine mites. Water that has contained adult female Arrenurus manubriator Marshall will elicit arrestant behaviour in conspecific adult males, and if the cue is sufficiently strong, the males will assume a readiness posture (with 4th pair of legs held over the back, bent anteromedially at the genuotibial joint) that is typically a precursor to coupling. Water that has not been exposed to female mites does not induce any behavioural response from male mites. Female-conditioned water that has been passed through a C-18 column does not elicit any response from male A. manubriator, while the rehydrated residue from the column does induce arrestant behaviour and may result in the readiness posture. The results from the C-18 extraction indicate that the pheromone is nonpolar in nature.