Levantamento de entomofauna em sistema agroflorestal e floresta de eucaliptos no norte do Rio Grande do Sul

Abstract

Agroforestry, or agroforestry system (AFS), integrates perennial woody plants with herbaceous plants, agricultural crops, forage plants, and animals, promoting high species diversity and ecological interactions. Considered an agroecological practice, agroforestry combines economic and environmental advantages, benefiting family farming by providing greater food security and savings. Insects play a crucial role in maintaining ecosystem stability by providing essential services such as pollination and pest control. This study aimed to estimate how insect richness and abundance vary between an AFS area and a eucalyptus forest. The research was conducted on a rural property in the municipality of Erval Grande, Rio Grande do Sul, currently transitioning to an agroforestry system. Forty-eight pitfall traps were installed in AFS and eucalyptus areas. Collections occurred weekly in March 2024, totaling four collections. A total of 23,755 insects from eight taxonomic orders were recorded, with Hymenoptera (56.78%) and Coleoptera (28.13%) being the most abundant. The complexity of the AFS resulted in greater richness, with the presence of six of the eight analyzed orders. Hymenoptera, were the most numerous in the AFS due to greater plant diversity. Coleoptera, essential in decomposition and pest control, were also significant. Even an AFS in an early stage of development showed important differences in individual abundance when compared to a monoculture system. In this sense, an AFS can act as a promoter of environmental complexity. Moreover, insects showed great potential as bioindicators of the development stages of an agroforestry system.