Behavioral Response of the Asian Corn Borer Ostrinia furnacalis Guenee (Lepidoptera: Pyralidae) and the Earwig Euborelia annulipes Lucas (Dermaptera: Anisolabiidae) to Selected Crops and Weeds Associated with Sweet Corn
The identification of crops or weeds that provide semiochemicals beneficial to crops, such as repellents for the insect pests and/or attractants to natural enemies, is important for pest management in the field. Ovipositional preference and behavioral bioassays were conducted to determine suitable companion plants for sweet corn that will enhance repellency for the Asian corn borer (ACB), Ostrinia furnacalis Guenee (Lepidoptera: Pyralideae), or affect the common earwig [Euborelia annulipes Lucas (Dermaptera: Anisolabiidae)]. In oviposition preference tests, lemon grass (Cymbopogon citratus Stapf) and eggplant (Solanum melongena L.) produced the greatest oviposition deterrence. As an oviposition host, eggplant reduces the number of egg masses on corn and has potential as a trap crop in sweet corn production as it does not support larval growth. Larvae were found to be very mobile on oregano (Coleus aromaticus Benth.) and sweet potato (Ipomoea batatas L.) and quickly dispersed in silken threads, landing on the soil and dying. Associated weeds such as Mimosa pudica L. and Ageratum conyzoides L. proved toxic to larvae. Earwigs were not repelled by lemon grass, eggplant, oregano and the test weed species extract. Field trials must be conducted to verify that lemon grass and eggplant can serve as good companion crops for sweet corn.
Key Words: companion crop, larval growth, oviposition deterrence, oviposition preference, predation