Cuticular lipids prevent desiccation in insects, and in some species, serve in chemical communication. The chemistry of insect cuticular lipids has recently been reviewed. In most species, hydrocarbons are the major lipid class present, and consist of normal, unsaturated, and methyl branched components which range in chain length from 21 to 50+ carbons. A number of reviews have described the application of 13C-nuclear magnetic resonance (NMR) to biosynthetic studies. A major advantage of 13C-NMR techniques to follow a labeled molecule in biosynthetic work is that the exact location of the labeled carbon can be readily ascertained without the need for degradative studies. Accurate interpretation of biosynthetic data from 13C experiments requires an unequivocal assignment of all resonances. Discussions of methods for assigning resonances in 13C-NMR spectra are available, and empirical rules for assigning resonances in the spectra of hydrocarbons have been summarized.