Changes in cuticular hydrocarbons in different developmental stages of the bean bug,Riptortus pedestris (Hemiptera: Alydidae)

The function of “cuticular hydrocarbons” (CHCs) in insects is to protect the body as well as chemical communication and recognition between species. Gas chromatography and mass spectrometry were used to compare the composition of CHCs in eggs, all nymph instars, and male and female adults of the bean bug, Riptortus pedestris (Hemiptera: Alydidae). CHC carbon chain numbers of each developmental stage ranged from 14 to 19 in eggs to the fourth nymph and were 24 in the last nymph. CHCs' carbon chain numbers in male and female adults increased from 16 to 23 and 16 to 27 until 6 days of age, respectively. Major components consisted of n-nonacosane in the larval stages, which changed to n-hentriacontane, n-heptacosane and 13,17-;15,19-demethyltritriacontane in adults. The major component from eggs was not identified. The major component from newly emerged adults was n-heptacosane. CHCs in different developmental stages of the bean bug consisted of n-alkanes with saturated hydrocarbons (27–63%), followed by mono or di-methyl alkanes. However, the CHCs of newly emerged female and male adults consisted mostly of methyl-alkanes. The major constituents of CHCs in the developmental stages of R. pedestris were proportionally different but showed only slight differences in composition.