Feeding mechanisms, and their variation in form, of some adult ground‐beetles (Coleoptera: Caraboidea)

Abstract

The structure of the mouthparts and foregut of some caraboid beetles has been correlated with their type of feeding mechanism. These may be adapted to fragmentary feeding, fluid feeding (where pre‐oral digestion is important), or to mixed feeding (a large category which ranges from a mainly fluid to a mainly solid intake). Head structures concerned with feeding have been discussed in relation to these methods; they include the mandibles, maxillae, labrum‐epipharynx and anterior foregut, proventriculus, labium‐hypopharynx and the head floor. Different types of head floor were denned in relation to gular structure, in particular the presence or absence of the mid‐gular apodeme. Convergent evolution of feeding mechanisms was noted amongst both fragmentary feeders and fluid feeders; in the latter group, sucking pumps have been evolved in the Carabitae, Scarites , Cicindelidae, Paussini and some other caraboids. It was suggested that head shape in caraboids may reflect locomotory adaptations more frequently than feeding adaptations.