The function of the metathoracic scent gland in corixid bugs (Hemiptera, Corixidae): secretion-grooming on the water surface

Publisher Website
Google Scholar
Abstract
The majority of the corixids investigated in the present study from time to time rub the metathoracic gland secretion over the body parts covered with hydrofuge hairs (Diaprepocorinae, Cymatiainae, Corixinae). In most genera the grooming act (‘secretion-grooming’) is performed while floating on the water surface and takes only 2–3 seconds. Diaprepocoris, unlike other corixids, grooms on land. The secretions contain unsaturated aldehydes which have strong antibacterial properties in two tested species. From the results obtained, it seems probable that the metathoracic secretion has the same function as in the water bug family Pleidae: it prevents the contamination of the hydrofuge hairs by killing attached microorganisms. Thus, it prevents the loss of the air store, which is held by hydrofuge hairs when submerged. In Micronecta and in all corixid nymphs no secretion-grooming occurs, although abdominal scent glands are present. Other additional functions of the corixid scent gland secretions and some aspects of the evolution of secretion-grooming in corixids are discussed.