Chemical Characteristics of the Proteinaceous Material in the Nests of Six Polistine Species (Hymenoptera; Vespidae)

Some chemical characteristics of oral secretions and larval silk, which contain proteinaceous substances, were analyzed in the nests of four Ropalidia species, R. fasciata, R. taiwana, R. rufocollaris and R. flavopicta, and two Polistes species, P gigas and P tenebricosus. Nitrogen contents in pure oral secretions ranged between 13-14%, and crude protein contents, calculated from the N contents, were 84-89%. The protein content in the larval silk was approximately 90%. The three major amino acids in the nest parts were Gly (23-48%), Ala (16-22%) and Ser (6-19%) in Ropalidia species, and Gly (20-32%), Ser (11-14%) and Pro (10-13%) in Polistes species. These items occupied about 60% of the residues. The three major amino acids in the larval silk were Ala (33-34%), Ser (19-21%) and Glx or Asx (9%). Ala and Ser comprised about half of the residues. In some species, the relative abundance of amino acids in the oral secretions varied depending on the parts of nest, especially in the proportion of Gly. Cluster analyses carried out on the amino acid compositions in the oral secretions generated two distinct groups: One consisted of the nest paper, which contained a small amount of secretion coating and the other consisted of secretion layers of the petiole and secretion membranes made at the bottom of Ropalidia cells. These results suggest a possibility that these wasps can produce oral secretions with different kinds and/or ratios of protein(s) according to their purposes, i.e., construction or maintenance.