Abstract
Bacterial isolates with insecticidal activity against aphids were examined. 1, 100 bacterial isolates were isolated from 617 samples (aphids: 437, other insects: 5, plants: 175) collected in the Tokachi district of Hokkaido from 1986 to 1990. Six of 582 isolates demonstrated insecticidal activity by spraying (HS) against the Foxglove Aphid (Aulacorthum solani) and the Green Peach Aphid (Myzus persicae). Six of 518 isolates also showed insecticidal activity by peroral inoculation (HP) against the Foxglove Aphid and showed a positive reaction to the Potato Rot Test. The mortality of the Cotton Aphid (Aphis gossypii) sprayed with HS isolates in a green house was high, but spraying of HP isolates caused low mortality.
