Pest Management of Wheat Stem Maggot (Diptera: Chloropidae) and Wheat Stem Sawfly (Hymenoptera: Cephidae) Using Insecticides in Spring Wheat

摘要

The effectiveness and timing of foliar insecticides and insecticidal seed treatments were evaluated for pest management of the wheat stem maggot, Meromyza americana Fitch (Diptera: Chloropidae), and the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), in hard red spring wheat in North Dakota. Treatments included: 1) untreated check, 2) foliar application of lambda-cyhalothrin at the 4-6 leaf stage, 3) foliar application of lambda-cyhalothrin at the flag-leaf stage, 4) low rate of thiamethoxam seed treatment, 5) high rate of thiamethoxam seed treatment, and 6) low rate of thiamethoxam seed treatment plus a foliar application of lambda-cyhalothrin at the 4-6 leaf stage. A foliar application of lambdacyhalothrin at either leaf stage significantly reduced the number of white heads caused by wheat stem maggot. The combination of a low rate of thiamethoxam seed treatment plus a foliar application of lambda-cyhalothrin at the 4-6 leaf stage also resulted in a significantly lower number of white heads. However, the low and high rates of thiamethoxam seed treatment alone were not effective at reducing the number of white heads. None of the treatments reduced the percentage of damaged stems from wheat stem sawfly. No yield differences were observed among treatments for either wheat stem maggot or wheat stem sawfly.