Ground weevil, corn insect pest
1988
Watchara Choonhawong | Auranuj Kongkanjana | Ocha Prachuabmoh (Dept. of Agriculture, Bangkok (Thailand). Entomology and Zoology Div. Corn and Other Field Crops Insect Pests Research Team)
Ground weevil, Calomycterus sp. (Col: Curculionidae) is a serious pest of corn in the seedling stage. The weevil causes damage to the seedling by feeding on the leaves, stems and germination seeds. It can cause death to corn seedling plants. The development of the weevil in the laboratory, the cycle from the egg deposition to adult was completed in 2 months. Eggs were laid in the ground and hatched in 7 days. The larval period is 45 days. Pupation lasted 5-7 days. In the laboratory the adults could live up to 8 months. The population was low at the beginning of the rainy season and was highest in August and September. After this period, the population decreased because the older plants were no longer suitable host. Nevertheless, if there are still young seedlings from late plantings the population may be increased. The efficacy of certain insecticides were evaluated against the weevil both in the laboratory and field test. The most effective insecticide was furathiocarb at 10, 20 gm., product/1 kg. seed, cargofuran and denfuracarb at 8 kg. product/ rai as well as carbosulfan 25 ST and heptanchlor at 20 gm. product/kg. seed, which also gave good control. In laboratory 3 foliar insecticides namely carbosulfan, EPN + methyl parathion and cypermethrin + monocrotophos at 30, 40 and 30 ml./201 gave complete control of this insect.
显示更多 [+] 显示较少 [-]