Occurrence Regularity And Control Measures Of Mamestra Brassicae In Ping, An County, Qinghai Province

In recent years,"vegetable basket" projects are increasing in Ping’an County Qinghaiprovince as adjusting the continuous optimization of planting industry structure andfavourable location in Ping’an County. Mamestra brassicae occurs in growing vegetableproduction. The control methods are not satisfactory, cabbage moth is an unstable anddifficult to grasp, easy to change, technical issues in sustainable development of vegetableindustry. The species seriously affect the quality of vegetables, reduce vegetable output andhave a serious impact on vegetable production in Ping’an County.This study described occurrence, damage, control methods based on the survey data. The keytechnologies are: understanding occurrence and biological characteristics, suitable time tocontrol of cabbage moth in Ping’an County, achieving the best protection of vegetableproduction. Through two years of progress achieved is as follows:During the field survey in2008-2009, we found the occurrence of cabbage moth, anaverage of8.72to9.0suffering strains in every12㎡vegetables growing areas, suitablehost followed by kohlrabi> rape> white cabbage> Chinese cabbage> radish> cucumber>eggplant. The effect on host plants differed among different stage larvae due to the longdevelopmental time.We found that cabbage moth has two generations a year in Ping’an County due to therelatively low temperatures, concentrating in the early summer to late fall. Adults arenocturnal, lurking surface of leaf vegetables in the bushes in daytime feeding in the evening.Females reproduced in the form of egg masses or eggs to the dorsal vein. Adults initiallyoccurred in May, outbreak in the end of June to mid-July, from mid-August, graduallyreduced to early September using insect forecast light traps. The local climate mainly affectedcabbage moth occurrence and temperature and humidity are significant factors that determinethe occurrence. The negative correlation showed between altitudes and the number of theadult.Screening the high-efficiency, low toxicity, and low residue pesticide is to determine thechemical control techniques by the experiments. The Pharmaceutical-effect test showed thatthe five kinds of common used pesticide have different efficacy. Insect adjust mortality ratio is typically used for characterization of pesticide effect. In one-day test, the control efficiencyselected from the highest to lowest are87.69%(deltamethrin),82.54%(cyhalothrin),69.23%(phoxim). And in one-week test, the control efficiency from the highest to lowest are96.43%(deltamethrin),96.26%(Abamectin and Lorsban),62.94%(phoxim). According to the studyof occurrence of cabbage moth and biological characteristics combined with the actualsituation of agricultural production in Ping’an county, the integrated control technology wasbeen confirmed.