Chemistry of the Cephalic and Dufour's Gland Secretions of Melissodes Bees1

Abstract
The cephalic secretions of both sexes of the anthophorid bees, Melissodes desponsa Smith and female M. denticulata Smith contain n-C20 to n-C27 hydrocarbons, n-hexadecanoic acid, and n-octadecanoic acid; male M. denticulata heads yielded 6 saturated and unsaturated butyrate esters from n-dodecyl butyrate to n-octadecyl butyrate. The Dufour's gland of M. desponsa contains n-tetradecyl acetate, dihydrofarnesyl acetate, and farnesyl acetate. Cephalic secretions may be used in aggregation, mating and defense; the acetates may serve to identify subterranean cells. The utilization of pheromones for wild bee pollination management is proposed.