BIOLOGICAL SOLUTIONS FOR THE MANAGEMENT OF PESTS IN CORN CROPS

Abstract

Corn crops in Romania shelter a large number of insects and spiders, some of them harm the plants (pests) while others are useful (natural enemies). Bearing in mind the wide variety of species present and the high numerical quantity of recent years, we set out to find and exploit those capable of keeping pests under control in the context of the current focus on biological solutions to the detriment of chemical ones. Thus, in 2021-2022 we analyzed the set of pests and natural enemies from 2 lots of corn grown organically, from 2 agricultural companies in the western region. The results showed a great diversity and positive interactions, analyzed both in the open field and in cages. The effectiveness rate of ladybugs in preying on aphids was high (81%) and that of spiders in preying on leaf beetles (Diabrotica, Oulema, Phyllotreta and Chaetocnema) was still high (76.25%). The activity of the parasitoid wasps was reflected in a lower effectiveness rate (parasitized aphids) (14.84%), as was the case of the oophagous wasps that parasitized 10.71% of Ostrinia and Helicoverpa eggs. The future approach to pest management in organic corn crops should include exploitation of existing natural enemies, an affordable solution at low cost.