Insetos associados a cultura do feijão-caupi em sistema de produção agroecológico, no Município de Ipanguaçu (RN)

Abstract

Cowpea (Vigna unguiculata) is one of the main crops in the Northeast region of Brazil, especially due to its hardiness and productivity. This study aimed to evaluate the population fluctuation of the main insect pests in cowpea cultivation in the municipality of Ipanguaçu, in the state of Rio Grande do Norte, Brazil. The experiment was conducted using the -landrace variety “Costela de Vaca,” with a prostrate growth habit, from October to December 2023, at the experimental field of the IFRN Agricultural School Unit (Ipanguaçu Campus). A 600 m² area (20 × 30 m) was used. The crop was cultivated under an agroecological system and received no phytosanitary treatment during the study, only cultural practices. Insects were monitored weekly using a 10x hand lens, with ten sampling points per week. Based on the data collected, population fluctuation graphs were developed for the main pests and natural enemies recorded throughout the cowpea crop cycle. Among the identified insects, the black aphid (Aphis craccivora), green leafhopper (Empoasca kraemeri), whitefly (Bemisia tabaci), leafminer fly (Liriomyza sativae), and the beetle (Diabrotica speciosa) stood out, along with natural enemies such as lady beetles (Coccinellidae) and metallic-colored flies (Dolichopodidae). The leafminer showed the highest population density in the experiment, with a moderate positive correlation with rainfall (r = 0.68) and relative humidity (r = 0.74). A strong and statistically significant correlation (r = 0.95; p = 0.003) was found between aphids and lady beetles, suggesting a functional response of the predator population to prey availability. The results highlight the importance of ecological monitoring and the conservation of natural enemies as sustainable pest management strategies in agroecological systems in the Brazilian semi-arid region.