Abstract

Ostrinia nubilalis Hüb. and Helicoverpa armigera Hüb. represent one of the most important maize pests in Serbia and Europe. Due to the pronounced polyphagy and the increasing number of generations per year, their control has been challenging. In addition to integrated pest management, insecticides application is usually inevitable. During 2023, efficacy experiments of the chlorantraniliprole insecticide (200 g/l a.s., SC) were conducted in order to control O. nubilalis and H. armigera in the DKC4098 and Pioneer 9911 maize varieties at two localities in Vojvodina according to EPPO methods. The insecticide was applied in a rate of 0.15 l/ha when the maize was in the BBCH 65-67. Foliar treatment was performed during moth flight, egg-laying of the second generation, when larvae are present and active. Three evaluations were performed. The first evaluation was conducted immediately before the treatment when the number of eggs and larvae was determined (25 plants per repetition). In the second evaluation 15 days after the treatment, the number of damaged plants and cobs was determined. The third evaluation, slightly before harvest, determined the number of stem-broken plants above/below the cob and the number of damaged cobs (20 plants per repetition). The results obtained were analyzed using the one-way ANOVA and LSD tests, and the efficacy was calculated according to Abbott. Immediately before the treatment, the average number of O. nubilalis egg litters ranged from 4.25 to 8.5 per repetition, while the H. armigera eggs were not found in any of the localities. The borer larvae of O. nubilalis before the treatment amounted to 1.25-3.25, and 1.0-1.75.0 for H. armigera. After 15 days, the efficacy of chlorantraniliprole was 80-85.3%. This insecticide significantly reduced the number of broken plants and damaged cobs compared to the control, based on the assessment right before the harvest. The efficacy ranged from 82% to 95.4%, indicating significant sensitivity of the pest populations to chlorantraniliprole.