Oligosaccharide composition and pheromonal activity of male tergal gland secretions of the German cockroach, Blattella gennanica (L.).

In the sequential courtship behavior of the German cockroach, Blattella germanica (Dictyoptera: Blattellidae), females feed on the tergal gland secretions from the male tergites. The phagostimulative components in the male secretions were composed of a complex mixture of oligosaccharides and phospholipids. Besides seven oligosaccharides previously identified, two new trisaccharides, O-alpha-D-glucopyranosyl-(1 --> 6)-alpha-D-glucopyranosyl alpha-D-glucopyranoside and O-alpha-glucopyranosyl-(1 --> 4)-O-alpha-glucopyranosyl-(1 --> 1)-myo-inositol, were characterized as the sugar components of the secretions. The activity of the sugar components was compared in combination with the lipid fraction. Individual oligosaccharides exhibited the activity either alone or synergistically with the phospholipids. A complex mixture of these primary substances in the tergal gland secretions, thus, serves as a pheromonal phagostimulant in the precopulatory behavior, strongly eliciting feeding response in the female cockroach.