Genital sex pheromones of ixodid ticks: 1. Evidence of occurrence in anterior reproductive tract of American dog tick,Dermacentor variabilis (Say) (Acari: Ixodidae).

The occurrence of a genital sex pheromone in the anterior reproductive tract of partially fed femaleDermacentor variabilis was demonstrated by extraction and bioassay. A new type of bioassay, the "neutered" female assay, was developed to test the potency of extracts or chemically defined fractions to stimulate males to copulate. Electrophysiological tests confirmed the ability of males to detect the pheromone with sensilla on their cheliceral digits.

Studies on possible role of catecholamines in regulation of sex pheromone gland activity in American dog tick,Dermacentor veriabilis (Say).

Administered monoamines affected sex pheromone activity in the foveal glands of the tick,Dermacentor variabilis (Say). Flooding the tissues of the female tick with reserpine, α-methyl-m-tyrosine methyl ester hydrochloride, and pilocarpine prior to feeding led to reductions in female sex attractant activity during engorgement. Similar treatments with cyclic AMP, dopamine, serotonin, 6-hydroxydopamine, and acetylcholine had no apparent effects on the attractiveness of feeding females.