Insecticide Investigations During 1930

Abstract

Molasses nicotine soap sprays, which have proven effective in the control of certain delicate insects, were applied with safety to a series of thirteen species of trees at a molasses dilution of 1-20. Tulip and gray birch showed slight injury at this dilution. Due to the dry seasons of the past two years, the chinch bug, Blissus leucopterus Say became a serious lawn pest in certain localities. A series of sprays and dusts were tested for its control, with potassium oleate plus nicotine appearing the most promising. A series of sprays were tested for the control of the rhododendron lace bug, Stephanitis rhododendri How., with results indicating the value of the spray when there was a thorough wetting of the insect.. Dormant oil sprays were demonstrated as effectively controlling oak leaf rollers, Argyrotoxa semipurpurana Kf., by killing the over wintering eggs. The tulip tree scale, Toumeyella liriodendri Gmel., was effectively controlled by certain dormant oil sprays, but only partial controls were obtained after foliation had taken place and the scale had advanced in growth and resistance. Field tests with dormant oils on sugar maples and black walnut demonstrated the injurious effects of such sprays on these trees. Spray injury tests with oil and lime sulfur on foliage of various trees revealed a certain type of injury characteristic of this combination, while combinations of soap and arsenate of lead on conifers also produced a characteristic type of injury.