Studies on Bionomics and Control of Oligochroa atriquamella Hampson

Lin Qingyuan, Senior Engineer, Cai Guogui, Lin Jilang (Forestry Bureau of Fujian Province, uzhou, 350003);Dai Yanhai (Foresty Bureau of Zhangzhou City, Fujian Province).

Oligochroa atriquamella Hampson, bionomics, control, Acacia mearnsii

Oligcchroa atriqumella Hampson is one of the moot serious pest of Acacia mearnsii in Fujian Province. This paper reports the results of the studies on the bionomics and control of this pest from 1988 to 1991. It has 6 generations a year in Huaan, Fujian Province. In the field, there is an overlapping, generation. The larvae over winter within thin cocoons in the twigs and leaves or in the thick growth of grass or the fallen leaves. The overwintering larvae pupate in late-March next year. There are five instars for the larvae and they do harm by curling leaves of the plant. The overwintering larvae last 117-148 days and the others last 16~24 days; The pupae last 8-15 days. The adults fly to light at night. The eggs are laid individually on the tender twigs and tender leaves or insects nest and the average number of eggs laid per female is 103.Control methods include hand-collection of the larvae. Spraying insecticides such as diluted 40% Omethoate 800~1 000 times, 50% Methamidophos 800~1 000 times, 20% Fenvalerate 2000 times and 2.5% Decis 4000 times, respectively, upon 3~5 th larvae in laboratory were found to be very effective with a mortality of 90%.