Multicomponent Mandibular Gland Secretions in Three Species of Andrena Bees(Hym., Apoidea)

Abstract

50 volatile constituents of the mandibular gland secretions in males and females of three species of Andrena bees, A. wilkella (Chr.), A. ovatula (K.) and A. ocreata (K.), been identified. The secretions are made up of a series of spiroacetals of four different systems together with monoterpenes and unbranched acyclic compounds. Many of the components, particularly several of the dominant ones, occur in both sexes of all three species, so that the volatile secretions are qualitatively very similar. Females contain about 100 |ig per individuum, which is 3- 5 times the amount o f the males’ secretions. Major spiroacetals are E, E- and Z, E -2,8-dim ethyl- 1,7-dioxaspiro[5.5]undecane and E, E- and Z,£-2-ethyl-7-m ethyl-l,6-dioxaspiro[4.5]undecane, while prominent monoterpenes are geraniol and citronellol. Straight chain hydrocarbons C17, C19, C21 and C23occur in fairly large amounts, mostly with increasing concentrations. With respect to the quantitative distribution of components of minor concentration, the bouquet of A. wilkella is clearly distinguishable from A. ovatula and A. ocreata which from the m orphological and ethological point of view are more closely related.Behaviour tests with A. wilkella indicate high biological activity of the main spiroacetal. © 1982, Walter de Gruyter. All rights reserved.