Foveal glands,source of sex pheromone production in the ixodid tickDermacentor andersoni stiles

The foveal glands of the Rocky Mountain wood tick,Dermacentor andersoni Stiles, are the sex pheromone glands from which the sex pheromone is released via the foveae dorsales. The sex pheromone, 2,6-dichlorophenol, was recovered from extracts of these glands by GLC. Other evidence of the role of these glands in sex pheromone production is described. A³⁶Cl-labelled volatile compound (or compounds) was (were) collected from partially engorged femaleD. andersoni fed in³⁶Cl-labelled hosts, but no labelled compounds were collected when the foveae dorsales were blocked. X-ray analysis revealed unusual concentrations of chlorine in the foveal glands compared to other tissues. Autoradiography also revealed significant accumulations of radiochlorine in the vicinity of these glands.Presumably, the foveal glands of the American dog tick,Dermacentor variabilis (Say), are the sex pheromone glands of that species also, since a³⁶Cl-labelled volatile was collected from female ticks fed on a³⁶Cl-labelled host. However, attempts to recover 2,6-dichlorophenol from gland extracts or volatile emissions fromD. variabilis were unsuccessful.Supported by grants AI 10,986 and AI 10,987 from the National Institute of Allergy and Infectious Diseases, U.S. Public Health Service, U.S. Department of Health, Education and Welfare, Bethesda, Maryland, 20014.