Gall-inducing and building habit in Lixinae weevils (Coleoptera: Curculionidae)

Abstract

Among the Lixinae, at least 35 species are gall inducers. Twenty six species have larvae with building activity (lists of both are provided). Fifteen species are root gallers (tribe Cleonini) and 20 species are stem gallers (Lixini). Their gall morphology (shape, colour, size), habitat peculiarities and typical gall development are described. A new classification of galls according to their inhabitants and formation is proposed. The data obtained suggest that galling depends on the thickness of the transformed plant parts. The potential benefits and costs of galling to gall inducers are discussed. Data on the diversity of parasitoids indirectly support a protective role for galls. A summary of information on special larval constructions is presented. Two types of such constructions are—the ground capsules and the trehalas. These are closed chambers whose walls consist of a small soil and plant particles bound with sticky larval secretions. Capsules and trehalas are attached to the plant and serve to complete preimaginal development. Both are functionally similar to galls.