Sex-Specific Food Preferences in the Madagascar Hissing Cockroach <Emphasis Type="Italic">Gromphadorhina portentosa</Emphasis> (Dictyoptera: Blaberidae)

For most insects, adult nutrition affects not only survival of individuals but also their reproductive output. In particular, fecundity of females commonly depends on ingestion of protein necessary for egg development, whereas male fertility is not highly protein dependent (Chapman, 1982; House, 1974; Engelmann, 1999). Furthermore, because insects generally are unable to convert lipids to monosaccharides (Bignell, 1981), carbohydrates and proteins serve as primary energy sources in both sexes (House, 1974). Recent studies reveal that a number of insects exhibit sex-specific differences in feeding behavior that are correlated with adult nutritional requirements. For example, young female tephritid fruit flies (Diptera: Tephritidae) that are protein-hungry are more attracted to odors of protein food baits than to odors of host fruit, whereas males and protein-fed females are attracted more toward fruit odors (Cornelius et al., 2000, and references therein). Female peacock butterflies (Inachis io) and Adonis blue butterflies (Lysandra bellagrus) prefer floral nectars rich in amino acids, but males discriminate among nectars in favor of sugar content (Erhardt and Rusterholz, 1998; Rusterholz and Erhardt, 2000).