REVIEW OF THE GONDWANAN APHIDS.

Endemic and indigenous aphid species are rare in most Gondwanan countries, being greatly outnumbered by aphids accidentally introduced from Europe or North America, or spreading naturally via Southeast Asia. Our limited knowledge of Gondwanan endemic and indigenous aphids is summarised here, with emphasis on Australia and New Zealand. Many undiscovered species are almost certainly present. Barriers to their discovery are discussed. Associations of aphids with ancient and endemic plants are considered in relation to continental history. Aphids have close functional relationships with a range of other organisms, including ants, wasps, flies and bacteria and some of the obligate relationships may also be Gondwanan. Neophyllaphis, Neuquenaphis and Sensoriaphis/Taiwanaphis have an unquestionable Gondwanan origin, as do southern Aphis and Paradoxaphis (Australia, New Zealand, South America). The subfamily Lizeriinae may have been the first to diverge from the basal Aphididae and has an exclusively Gondwanan distribution. The subfamily Greenideinae is another early group and is composed of genera with a Gondwanan distribution. Species in these genera occurring in both Australia and Asia/Southeast Asia can be considered native, but not endemic to these areas. Greenidea and Schoutedenia are thus Australian natives. Aphis clerodendri and (less convincingly) Aphis eugeniae have a Gondwanan distribution. The genus Sitobion (Macrosiphini) has many species probably endemic in various Gondwanan countries and most likely has a Gondwanan origin. Aphidiine wasps (Braconidae), primary parasitoids of aphids, have a well-supported southern origin, and the hyperparasite Alloxysta, by virtue of its host-specific relationship with southern aphids and aphidiine wasps, may also have southern roots. [ABSTRACT FROM AUTHOR]