Insect damage in maize of highland Ecuador and its significance in small farm pest management

Abstract

Abstract Insect pests and their damage were observed in a new early‐maturing maize variety and a common traditional variety, cultivated with and without chemical fertilizer in highland Ecuador. Observations were made on unsprayed experimental plots from farmers’ fields: at early whorl (25–29 days after planting), mid‐whorl (69–80 days), and during ear maturation (148–203 days after planting). Foliar damage by the principal pests Agrotis deprivata and Dargida grammivora larva was minimal. The early‐maturing variety suffered significantly more earworm damage from Ecuador's three principal pests of ripening maize: Heliothis zea, A. deprivata and Euxesta eluta. Of the traditional and early varieties respectively, 24.4% and 35.6% of the ears were damaged by Lepidoptera larvae, and 19.5% and 24.2% by E. eluta. The greater damage observed in the early variety may be the result of reduced husk tightness. Two parasites were reared from A. deprivata larvae collected in maize whorls, Thymebatis sp., Fam. Ichneumonid...