[The effect of subsocial behaviour of the seed-sucking bugsOncopeltus fasciatus dall. andDysdercus fasciatus sign. on their nutrition].

The quantitative uptake of food of isolated individuals or groups ofOncopeltus fasciatus andDysdercus fasciatus has been investigated comparatively. In groups of both species (2-4 members) the feeding activity and the volume of food ingested is increased. The subsocial behaviour is found to have more influence on unattractive food than on optimal one. The subsocial behaviour ofD. fasciatus andO. fasciatus exhibits intraspecific differences. The function and importance of the watery saliva is discussed emphasizing the functional relation of subsocial behaviour and economy of salivation of these seed-sucking species.