Entomofauna Associated with Corn Cultivation and Damage Caused by Some Pests According to the Planting Season on the Ecuadorian Coast

Corn (Zea mays L.) is an important cereal for food sovereignty, extensively planted due to its adaptation to various agroecological conditions. Climatic conditions and pests can affect its production. Concerning the latter, natural enemies could be considered in biological control programs. The objective of this study was to estimate the influence of the presence of insects, damage to plants and cobs, and their incidence on corn yield in two planting seasons. During the rainy (February to May) and dry seasons (Jun to October) of the year 2023, in Calceta, Lodana, and Quevedo, three important corn-growing areas on the Ecuadorian coast, corn plots of 1126 m2 were planted. The diversity of phytophagous and natural enemies was estimated. Damage to young plants and cobs was observed, and corn yield was determined. Of the 9073 insects observed, 44.2% and 55.8% constituted phytophagous and natural enemies, respectively. A moderate diversity (Shannon-H Index = 2.474–2.629 and Margalef Index = 2.734–3.110) of insects associated with corn was determined. Yield (range: 6.9 to 15.3 t) was negatively correlated with rainfall and cob damage (p < 0.05). Although precipitation is necessary for planting in rainy season, frequent and intense rains could be affect corn yield.