Abstract
Aphidoletes aphidimyza, an aphidophagous species of Cecidomyiidae, has been used in many countries as a biological control agent against aphids, particularly in glasshouses. The species had been reported previously in Japan but a mass-rearing method has not yet been established. Recently, preliminary tests started in Japan to evaluate its effect on aphids using mass-produced cocoons imported from the Netherlands and United Kingdom. Therefore, the natural distribution and host range of A. aphidimyza in Japan was studied before Japanese populations are contaminated by mating with imported individuals. Field surveys in 25 prefectures revealed that A. aphidimyza is distributed commonly in Japan, except in Okinawa, the most southern prefecture. Nineteen aphid species were observed to be attacked by the Japanese populations of A. aphidimyza and the larvae of imported A. aphidimyza were reared to adults on 7 aphid species. As a result, at least 80 host aphid species have now been recorded in the world. Most of the host aphids found in Japan belonged to the tribes Aphidini or Macrosiphini of the subfamily Aphidinae. The host plants of these aphids were also recorded.
