Plantas de cobertura de solo de inverno e seus efeitos sobre a abundância e diversidade de parasitoides na cultura do milho

Abstract

Maize cultivation is an important source of income for farmers and also for Brazil. In addition, it serves as an alternative for grain production, for food and feed. However, pest insects are one of the main responsible for the fall in production and an alternative to minimizing these problems, caused by insect pests, is the use of biological control. In this regard, the use of attractive plants for natural enemies becomes increasingly important due to their provision of food, shelter and adequate place for hibernation. With the purpose of exploring this capability of attractive plants, this study aimed to evaluate the potentials that the straw of winter species used as cover crops have, in harboring parasitoids in the maize crop. The experimental design used in this study was of randomized blocks, with five replicates and four treatments, being (T1) - vetch; (T2) - black oat; (T3) - consortium of oats with vetch and (T4) - fallow (control). Cover crops were sown in June 2015 and desiccated after the vetch reached full bloom and when oats were in the milky grain phase. After the desiccation of cover crops, maize sowing was performed and samplings in the emergence (VE), eighth leaf (V8), pimento (VT) and dough (R4) stages were carried out. The individuals sampled were screened and identified to the family level. The analyzed variables were abundance and diversity of parasitoids. A total of 183 parasitoids belonging to 10 distinct families were identified: Aphelinidae (3.28%), Braconidae (12.02%), Eucoilidae (7.64%), Eulophidae (2.19%), Eurytomidae (0,55%), Ichneumonidae (15.30%), Mymaridae (18.58%), Tachinidae (2.73%), Torymidae (16.40%),Trichogrammatidae (2.73%) and unidentified (18,58%). It is possible to conclude that none of the cover crops has the same attractiveness of parasitoid insects.