玉米蚜（Rhopalosiphum maidis）係玉米及高粱主要害蟲之一，近年來因推行稻田轉作，部份地區耕作制度隨之轉變，於玉米後作之春作高粱栽培區，生育初期普遍發生危害，影響植株生長至鉅。因高粱易發生藥害，防治上必須慎用殺蟲劑。本研究在查明植株上玉米蚜族群消長及防治方法。經3年調查結果，玉米蚜在高粱植株上之發生，自播種發芽後成蟲開始出現繁殖及危害，輪生後期為發生高峰，至孕穗期漸減，於抽穗開花後漸消失。其防治藥劑，以25％ Metasystox(i) 500倍最理想，75％ Furadan W.P 1500倍及31.6％ Pay off E.C. 5000倍次之。
Studies on the Population Fluctuation and Control of the Corn Leaf Aphid on Sorghum
Yen, F. C. and T. F. Huang
The corn leaf aphid, Rhopalsiphum maidis, is one of the most important insect pests of corn and sorghum in Taiwan. Because of the change of cropping system, the occurrence of aphid on spring sorghum after fall crop of corn is very devastating. Information of population fluctuation and the control measures screening of insecticides for the control of this study was aimed at screening of insecticides for the control of this insect and studying the population dynamics of this insect on sorghum. Results are summarized as follows:
1. Aphids were commonly observed in young sorghum plants after germination. However, population peak of the aphid was found at the late whorl stage. After booting stage the population decreased and disappeared during the heading stage.
2. Results of the insecticide screening tests indicated that 25% Metasystox (i) E.C. was the best, followed by 75% Furadan W. P. and 31.6% Pay off E.C., for the control of aphid on sorghum. No phytotoxicity was observed in the tests.
Accepted for publication: November 1, 1991.