Hitchhiker or parasite? A ceratopogonid midge and its odonate host

(Accepted 2 May 1997) The ceratopogonid genus Forcipomyia Meigen (Diptera: Ceratopogonidae) con­tains species with a wide range of adult biologies. Species of the subgenus Pterobosca Macfie are phoretic and apparently parasitic on the wing veins of other insects, notably odonates and sometimes lacewings. We describe F. (Pterobosca) debenhamae from Brunei as new to science, taking the authorship of Cranston, tabulate the morphological diversity of the subgenus, and speculate on the phylogeny. The behaviour of adult female midges, which have been found only upon the thorax of hosts predominantly of Libellago hyalina (Odonata: Chlorocyphidae), appears to deleteriously impact on the quality and duration of territory holding of the host. The lack of any confirmation of host feeding leads us to speculate on the nature of the association.