Cuticular hydrocarbons of winged and wingless morphs of the ectoparasitoid Choetospila elegans Westwood (Hymenoptera: Pteromalidae) and its host, larval lesser grain borer ( Rhyzopertha dominica) (Coleoptera: Bostrichidae)

Abstract

1. 1. The cuticular hydrocarbons from winged and wingless morphs of Choetospila elegans, a larval ectoparasite of several internal-feeding stored product beetle pests, were characterized. 2. 2. All four morphs share the same cuticular hydrocarbons, with the major components being n-alkanes (C 21-C 33). 3. 3. The minor components are 3-, 11- and 13-methyl branched alkanes and Z-10-monoenes. 4. 4. Two-way analysis of variance (sex and wing morph) shows that males and females have the same profiles, whereas four components showed significant differences between wingtype morphs. 5. 5. Only one of these four hydrocarbons (n-C 31) was a major component. 6. 6. The cuticular hydrocarbons of larvae of the lesser grain borer, Rhyzopertha dominica, were also characterized. 7. 7. Although the beetles' major components were the same n-alkanes as those found on the adult parasites, their minor components were different. 8. 8. Thus, the beetle larvae have no alkenes, but instead have 3-, 11-, 13- and 15-methylbranched alkanes, as well as a series of 11,15-dimethylalkanes. 9. 9. A cuticular hydrocarbon profile obtained on a population of C. elegans winged females that had been reared on rice weevil larvae was nearly identical to that from winged females reared on the lesser grain borer larvae.