Cuticular hydrocarbons of the sunflower beetle, Zygogramma exclamationis

Abstract

Hydrocarbons were the major lipid class on the cuticular surface of adults, nymphs, and eggs of the sunflower beetle, Zygogramma exclamationis, characterized by gas chromatography-mass spectrometry. Minor amounts of wax ester from 40 to 48 carbon atoms in size were only detected in larvae. The hydrocarbons ranged in size from 23 carbons (tricosene) to 56 carbons (trimethyltripentacontane) and were largely methylalkanes. The major components from females were 13,17,21-trimethylnonatriacontane (19%) and from larvae was n-nonacosane (17%). Males had 11,15- and 9,15-dimethylheptacosane (11%) and 13,17,21-trimethylnonatriacontane (11%) as the major components. In a sample of eggs, 13,17,21-nonatriacontane (16%) was the major component which was approximately 3 to 4-fold greater than the next most abundant hydrocarbons, dimethylheptacosanes, 2-methyloctacosane, methylnonacosanes, dimethyl- and trimethylheptatriacontanes and dimethylnonatriacontanes.