Male sternal pheromone glands in Acanthosomatid shield bugs from Britain.

Pheromone glands are present in the abdominal sternites of the pregenital region in the male adults in all British species of Acanthosomatidae. Secretory units are most numerous in the hawthorn bugAcanthosoma haemorrhoidale and maternal bugElasmucha grisea, next most numerous in the birch bugElasmostethus interstinctus, and least numerous in the juniper bugCyphostethus tristriatus. The largest dorsal abdominal scent glands were found inCyphostetheus. Ordinary dermal glands are also present. They are most numerous along the lateral margins of the abdomen. It is possible that Pendergrast's organ is the source of a female-produced pheromone. Secretory units were numerous in this organ inC. tristriatus female adults.