Asparagine-rich fibrous protein of the cocoons of parasitic wasp Cotesia (=Apanteles) glomerata, Braconidae, was investigated. A partial 255 amino acid sequence of presumable core domain was deduced from PCR product using larval cDNA and primers designed by internal peptides of the protein. It was found to be characterized by an extensive array of alternating asparagines consisting of XN repeat (X is serine or alanine, N is asparagine). We name this novel protein Xenofibron. Cotesia glomerata (Braconidae) Biochemistry; Genetics; Ecology; Animal constructions Cotesia glomerata; Nucleic acids; Novel asparagine rich fibrous protein partial cDNA sequence; Proteins; In cocoons; partial cDNA sequence & deduced amino acid sequence; Novel asparagine rich fibrous protein; Molecular genetics; Cocoons none