Cuticular hydrocarbons of Calliphora vomitoria (Diptera): relation to age and sex.

Changes in epicuticular hydrocarbon content and composition were examined from 3 to 120 hr postemergence in both sexes of Calliphora vomitoria. n-Alkanes and mono- and dimethylalkanes with 20 to 31 carbon atoms were the major hydrocarbons detected. Alkenes were only detected in the females. Males had fewer hydrocarbons (40 versus 49 for the females). In males this number remained constant from 3 to 120 hr, whereas in females the number increased progressively from 3 to 48 hr. The males had a greater total of hydrocarbons than the females (x6 versus x3.5). They had significantly more hydrocarbons by 48 hr, the time of sexual maturation, while in females, the hydrocarbon content increased between 6 and 24 hr postemergence, just before the onset of previtellogenesis. Hydrocarbon synthesis continued up to 120 hr in males, but remained constant in the females after 24 hr. Hydrocarbon composition differed in males and females and between the young (3 and 6 hr) and the older animals (24 to 120 hr). The young animals were characterized by the presence of monomethylalkanes with chain lengths over 25C and the older animals by monomethylalkanes with chain lengths less than 25C. Alkenes were found only in females. The males were characterized by the presence of di- and monomethylalkanes with 23, 24, and 26 carbon atoms.