Current insect pest problems in corn and their management in the Philippines
1987
Rejesus, B.M. | Javier, P.A. | Bato, S.
Of the 47 insect species recorded feeding in corn, four are considered major problems in its production. These are the corn seedling maggots (Atherigona oryzae Malloch.), the root grubs (Leucopholis irrorata (Chev.)), the corn borer (Ostrinia furnacalis Guenee) and the corn earworm (Helicoverpa armigera Hubn.). The most damaging is the corn borer, the other pests may cause sporadic damage. An integrated management scheme for controlling corn borer is recommended based on control action threshold (CAT) and knowledge of the appearance of the larvae at the whorl and tassel stages of the corn plant. It involves the integration of early planting with proper timing of application of chemical or microbial (Bacillus thuringiensis var. kurstaki) insecticides based on CAT or the inundative release of the egg parasite (Trichogramma evanescens Westw.) or the release of the egg-larval predatory earwigs (Euborellia stali Dohrm.) at whorl stage and the combination of detasseling technique with the application of chemicals or B.t. var. kurstaki at the tassel stage. Two CAT parameters are currently recommended: (1) greater than 100 larvae/100 plants, and (2) 50% corn plants showing corn borer leaf feeding holes (pin-match and shot-sized). At present, the chemicals recommended for integration are carbaryl, carbofuran, chlorpyrifos methyl + BPMC, cypermethrin, deltamethrin, emulsifiable concentrate and granular formulation of endosulfan, methomyl and monocrotophos.
显示更多 [+] 显示较少 [-]