The chemical composition of the spermatophore in some species of phaneropterid bushcrickets (Orthoptera: Tettigonioidea).

Male bushcrickets transfer large spermatophores of up to 40% of male body mass to the females during mating. These large nuptial gifts are later consumed by the female and have been shown to affect the size and number of eggs laid after mating in some species. The composition of the spermatophores in five species of phytophagous phaneropterid bushcrickets (genera Ancistrura, Barbitistes, Metaplastes, Poecilimon) was examined in respect to water content, elemental composition, protein concentration, and the content of lipids, carbohydrates, urea and uric acid. In addition, the amino acid composition of the spermatophore was compared with that of the egg proteins. In all species, water content was found to be about 85% of wet mass. Eleven to 16% of the dry mass consisted of nitrogen, corresponding to a protein content of about 70 to more than 90% of the dry mass. Urea and uric acid were only present in traces. The proteins contained a high amount of glycine (about 26mol %), together with asparagine/aspartic acid, 12% and glutamic acid, 11%, which differed distinctly from the amino acid composition of the egg proteins. The results are discussed with respect to the advantages the male may receive by producing these large nuptial gifts.