No CrossRef data available.
Published online by Cambridge University Press: 31 May 2012
Three insecticides — lindane, dieldrin, and Sevin — were tested for control of the Douglas-fir cone midge, Contarinia oregonensis Foote (Diptera: Cecidomyiidae). They were applied to infested duff samples at the rate of 1.5 pounds of insecticide in 15 gallons of diesel oil per acre. Lindane was the most effective, causing a 98.5% reduction in the number of midges emerging from the duff. Dieldrin also caused a significant reduction in emergence, but Sevin was no more effective than diesel oil alone.
The results of this test suggest that oil-based sprays applied to the duff before the cone midges emerge might give satisfactory control more consistently than the water-based sprays which are usually applied to the trees. The test procedure would avoid the timing and formulation problems involved in treating developing cones on the trees.