Camerini, G.; Maini, S.; Limonta, L. Impact of Chemical Insecticide Application on Beneficial Insects in Maize. Insects 2024, 15, 224, doi:10.3390/insects15040224.
Camerini, G.; Maini, S.; Limonta, L. Impact of Chemical Insecticide Application on Beneficial Insects in Maize. Insects 2024, 15, 224, doi:10.3390/insects15040224.
Camerini, G.; Maini, S.; Limonta, L. Impact of Chemical Insecticide Application on Beneficial Insects in Maize. Insects 2024, 15, 224, doi:10.3390/insects15040224.
Camerini, G.; Maini, S.; Limonta, L. Impact of Chemical Insecticide Application on Beneficial Insects in Maize. Insects 2024, 15, 224, doi:10.3390/insects15040224.
Abstract
The European corn borer (ECB) and in a lesser extent the western corn rootworm (Diabrotica virgifera virgifera LeConte) are a threat to maize in the Po Valley (Northern Italy), and its control can require insecticide applications. The results of a study to assess the effects of insecticide sprays on the beneficial insect Trichogramma brassicae (Hymenoptera Trichogrammatidae) and aphid predators are reported. A three-year research was carried out in two study areas, in Lombardy. In area 1, crop rotation was a common practice, while in area 2, maize monoculture was practiced. The ordinary trend of ECB egg masses attacked by T. brassicae was affected and parasitism rates were reduced as a result of exposure to insecticides (chlorpyriphos methyl, cypermethrin, alphacypermethrine, teflubenzuron). Repeated maize crop and insecticides spraying increased the aphid population abundance and negatively affected the aphid predator community, which mainly included ladybirds, hoverflies, bugs and lacewings. In sprayed fields, managed according to repeated crop protocols, the predator community was dominated by hoverflies, whereas ladybirds and Orius spp. prevailed in maize fields managed according to crop rotation protocols. Crop rotation protocols help to prevent ECB outbreaks; when threshold limit can be at risk, inundative release of T. brassicae or microbial control (i.e. use of preparation of Bacillus thuringiensis) can integrate natural biocontrol, a valuable alternative to chemical insecticides.
Keywords
Trichogramma brassicae; aphids; predators; parasitoids; insecticide side effects; Northern Italy
Subject
Biology and Life Sciences, Insect Science
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
