Orchidophilus aterrimus

June 2001. Orchidophilus aterrimus (Waterhouse) is a problem in some orchid stocks at the National Capital Botanical Gardens, Port Moresby, Papua New Guinea. Several insecticides were applied over several months, but it was not possible to eliminate the problem. Information on insecticides was requested.

Sprays of Confidor (Imidacloprid) were suggested: 0.25-0.5 g/l at 2-week intervals. It is a stomach poison, systemic and with a rather long residual activity. It is also very active against aphids, mealybugs and scale insects. However, it was also said to be very poorly absorbed through leaves, so often the level of control following foliar application is very poor. As a foliar application, it is highly persistent and highly disruptive to IPM programs. Parasitoids are particularly susceptible. In shade house conditions, Confidor kills 100% of parasitoids for sileverleaf whitefly for at least 21 days post spray. The only way to effectively use Confidor is as a soil application into the root zone.