Modification of cuticular hydrocarbons of Cryptotermes brevis (Isoptera: Kalotermitidae) in response to temperature and relative humidity.

Abstract To assess their ability to modify cuticular hydrocarbon (CHC) composition and survive adverse conditions, Cryptotermes brevis (Walker) nymphs were subjected to various combinations of temperature and relative humidity. Cuticular hydrocarbon profiles of C. brevis were consistent with previous studies. Alkenes were the most prevalent in the CHC mixture, comprising 54.5% of the total hydrocarbon ( n = 12), whereas n-alkanes and branched alkanes comprised 24.8 and 6.3%, respectively. Sixteen compounds yielded >2% of the total hydrocarbon and were subsequently tested for temperature and humidity effects in two successive experiments. In both experiments, temperature effects were found: n-C29 increased and n-C25 decreased with increasing temperature. Similarly, five compounds ( n-C25, n-C27, n-C29, C39:2, and C41:2) were analyzed for relative humidity effects in experiment 2, based on the results of experiment 1; only C41:2 indicated a significant positive relative humidity effect. The remaining 11 com...