Comparison of oligosaccharide compositions in male nuptial secretions of three cockroach species of the genus Blattella.

Male cockroaches of the genus Blattella secrete courtship pheromones from abdominal tergal glands. Conspecific females mount courting males and feed on their tergal exudates. In the German cockroach, B. germanica, a complex mixture of oligosaccharides was previously identified as the major phagostimulants in the male tergal secretion. We compared the oligosaccharide compositions of three Blattella species from different habitats, B. germanica (house), B. lituricollis (field), and B. nipponica (forest), by gas chromatographic (GC) analysis of their trifluoroacetylated derivatives. The three possessed a series of maltooligosaccharides and oligoglucosyl trehaloses with alpha1-->4 and alpha1-->1 linkages in common. However, B. germanica was conspicuous for its accumulation of a oligoglucosyl trehalose with a alpha1-->6 linkage [O-alpha-D-glucopyranosyl-(1-->6)-alpha-D-glucopyranosyl alpha-D-glucopyranoside] as the most prominent component of the secretion. Such diversification of the male pheromonal compositions within the genus might be reflected by biosynthetic systems in males and chemosensory properties in females suited for their natural habitat.