BATESIAN AND MULLERIAN MIMICRY BETWEEN SPECIES WITH CONNECTED LIFE HISTORIES, WITH A NEW EXAMPLE INVOLVING BRACONID WASP PARASITES OF PHORACANTHA BEETLES

Members of two endemic Australian genera of Braconidae, the helconine Trichio- helcon and the doryctine Acanthodoryctes, possess remarkable dense setosity around the propodeum and anterior metasomal segments which gives these regions a brilliant silvery-white appearance that contributes greatly to their overall colour patterns. Scanning electron micrographs are presented showing that two very different modified hair structures are involved, flattened ones in Acanthodoryctes and fused ones in Trichiohelcon. Diagnostic features of Trichiohelcon, Acanthodoryctes and two other genera of Braconidae parasitic on Phoracantha with similarly coloured species, Callibracon and Syngaster, are described and illustrated. Gymnoscelus rufoniger Turner is transferred to Trichiohelcon and features enabling its separation from T. phoracanthae are illustrated. Possible reasons for the evolution of the specialized reflective setae and their consequent effects on overall colour pattern are discussed in the general context of the development of homeochromy between species with linked life histories such as parasitoids and their hosts or predators and their prey, and the occurrence of this type of mimicry is surveyed.