![]() Small larvae 12 to 18 millimetres (0.5 to 0.7 of an inch) pose the greatest potential for damage as they will still feed and grow.Warmer, south facing slopes may show damage first. Scout the fields and inspect seedlings every three to four days during the first few weeks of crop development, looking for bare areas, holes or notches in foliage, and plants that are wilting, toppling over or completely cut off. The key to minimizing damage is early detection. ![]() Replacing injured plants with new transplants after each damage count appeared to offer means of assessing speed of action of insecticides against cutworms. Treatment differences appeared to be more pronounced when the larvae were confined by barriers than when released into open plots. The treatments in general did not reduce injury to non-economic levels during the first 7 days after the plots were infested. Increasing the rate of application of each, with the exception of Dylox, Guthion, and Sevin, provided increased protection to the flue-cured tobacco. Rates of application were based on relative toxicities determined by laboratory bioassay.The test insecticides in terms of relative effectiveness were rated as follows: endrin > aldrin = dieldrin = heptachlor > DDT = Dylox > Guthion = Sevin. Broadcast spray treatments of eight insecticides were incorporated into Berrien sandy loam soil before planting for control of artificial infestations of the black cutworm, Agrotis ipsilon (Hufnagel), attacking flue-cured tobacco.
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