In some literature (Bense, 1995) Agapanthia intermedia is only regarded as a variation of Agapanthia violacea (Fabricius, 1775). Here, it is regarded as a valid species. This opinion is mainly supported by differences between the larval morphology of both species (Svácha, in literis). Agapanthia intermedia seems to be monophagous on Knautia arvensis. In Central Europe it is quite common and can be found on the host-plant.
The living beetle was reared from larva collected in stalk of Knautia arvensis. The larva feeds centrally in the stalk. Before pupation the larva cuts off the upper part of the stalk, and secures itself in the lower part by a wad of fibrous frass (cf. Figure 1). Adult creates a new exit hole in the side of the stalk (cf. Figure 2). The mounted beetle in the lower picture was collected on Knautia arvensis in Pitkovice (Prague, Central Bohemia, Czech republic).
Collected by M.Hoskovec and M.Rejzek.
MH & MR © August 27, 2007