and females, and is also expressed sexually dimorphically in the abdominal ganglia of males. It acts in part as a stress peptide through regulation of food intake and metabolism and in males specifically, it both enables sperm transfer and sets copulation duration. In the American cockroach Periplaneta americana, [Arg(7)]-corazonin acts as a cardiostimulatory neuropeptide and accelerates the heart beat. It also causes contractions of the hyperneural muscle, however this has not been seen in other cockroach species. [His(7)]-corazonin acts as a hormonal factor in locusts and can cause dark pigmentation in albino migratory locusts (Locusta migratoria) and in green nymphs of the desert locust Schistocerca gregaria. While corazonins found in crickets and moths have no effect on body colour of the crickets or moths themselves, they can cause dark pigmentation in albino nymphs of the migratory locust (Locusta migratoria). In silkworms (Bombyx mori), corazonin reduces the spinning rate of silk. References Neuropeptides