Identification of cuticular hydrocarbons and the alkene precursor to the pheromone in hemolymph of the female gypsy moth, Lymantria dispar.

摘要

Hydrocarbons were extracted from the surface of the cuticle and from the haemolymph of adult female L. dispar. GC and GC/MS analysis indicated that the cuticular hydrocarbons with chain lengths >21 carbons were the same as those found in the haemolymph. These consisted of mostly saturated straight chain hydrocarbons with heptacosane the major component. Methyl branched hydrocarbons were also identified including a series of tetramethylalkanes with chain lengths of 30, 32, and 34 carbons. In addition to those found on the cuticle surface, the haemolymph contained the alkene pheromone precursor, 2-methyl-Z7-octadecene and two saturated analogues, 2-methyl-octadecane and 2-methyl-hexadecane. No evidence was obtained for the presence of the pheromone2-methyl-7,8-epoxy-octadecane in the haemolymph. Pheromone gland extracts indicated that small amounts (<1 ng) of the alkene precursor were also present in the gland. Relatively larger amounts of the alkene precursor were found in the haemolymph at the time when pheromone titres were higher on the gland. The presence of the hydrocarbon pheromone precursor in the haemolymph is discussed in relation to possible biosynthetic pathways for producing the gypsy moth pheromone.