1999 Volume 34 Issue 4 Pages 489-496
Natural enemies of Thrips palmi were surveyed on Okinawa and Ishigaki Islands of the Ryukyu Islands, to identify potentially effective, indigenous natural enemies against this adventive pest. A number of predators were found : Piocoris varius. Orius tantillus and O. strigicollis were collected on Okinawa Island, while P. varius. O. tantillus and Campylomma chinensis were collected on Ishigaki Island. Of these indigenous predators, P. varius is most likely to be effective against T. palmi in wax gourd gardens on Okinawa Island. Outbreaks of T. palmi were found just after its accidental introduction into the Ryukyu Islands in 1980, but there have been no serious outbreaks on the islands since several years after the introduction. Our study indicates that the indigenous complex of natural enemies may play a key role in suppressing T. palmi populations in southern Japan. Potential use of the generalist predators on the Ryukyu Islands for the biological control of greenhouse pests under short-day conditions in more northern temperate regions is also suggested.
