Current status of New Zealand indigenous aphids

This report summarises our current knowledge of the New Zealand indigenous aphid fauna. Size of fauna. Based on present knowledge, estimates of the size of the New Zealand indigenous aphid fauna range from 12 to 16 species. Six indigenous species have been fully described and named. A further six species are almost certainly indigenous to New Zealand but have not been fully described. There is good evidence for the existence of another two species and some evidence for another two species. More species are likely to be discovered. Taxonomic distinctiveness. The New Zealand indigenous aphids constitute a distinctive taxonomic component of the New Zealand fauna and the world aphid fauna. They have Gondwanan affinities and other unique features. At least two genera are endemic. They also support what appears to be a unique i ndigenous parasitoid (parasites that kill their hosts) fauna of unknown size. Biology and ecology. Very little is known about the biology and ecology of any species of indigenous aphid. One characteristic feature of the Aphis/ Paradoxaphis group is their patchy but very aggregated distribution. Population status. Only three species, Neophyllaphis totarae, Sensoriaphis nothofagus and the undescribed aphid on Dracophyllum, can be considered to be relatively common. The remaining species are now known from either one or two populations or have not been seen recently. Survey and collection. Extensive surveys have been completed of some species with little attention given to others. Recent surveys reinforce previous perceptions that, apart from three species, most indigenous species are difficult to find. Threats to survival. New Zealand indigenous aphids face a number of threats to their continued survival: from habitat destruction, displacement by introduced aphids, and attack from introduced parasitoids and predators. The relative importance of these threats has yet to be determined.