Study On The Biocontrol Technique Of Coleophora Dah(?)rica

This paper reviewed the domestic and overseas history of outbreaks and control of Coleophora spp. , and studied the biological and ecological characteristics of Coleophora dahurica Flkv DaXing'An Mountain forest areas of Inner Mongolia. C. dahurica has one generation a year. Adults emergence from first ten days of July to first ten days of June. The beginning of submit is 18, July, submit 22, July, end of submit 28, July. A female lays 19 eggs on average. However, the number would be up to 40 on condition that the population density is increasing. Among 10~40-year old larch stands, aggressed severely, the 20-year is the most. The population density is higher on the lower hillside or the leeward side of stands with a sunny exposure, the edge than inside, upper hillside than middle, sunny than shady, and decreased with the increase of the altitude.Based on the studies on population, damage level and outbreak frequency, the aggressed areas were divided into three types: areas with frequent outbreaks, areas aggressed occasionally and areas without outbreaks, and the outbreak level was divided into slight, middle and severe three levels with the population density of 10-25, 25-50 and >50 heads per meter long branch respectively. After the system studies on the schedule of laying eggs, hatching, development of larvae, pupation and er ergence, the outbreak period and the population density were predicted. Using SPSS software, two models were established, which one was Y=219.752+3.059XX1-0. 103XX2-5. 291X Xa+1. 859XX4-4. 316 XX5 (Y: population density of next year; X1: mean temperature of current year; X2: annual rainfall of current year; X,: mean relative humidity; X4: highest temperature of current year; X5: lowerest temperature of current year; ) and another was Y=-6. 651×X1+0. 139×X2-3. 595× Xs+1. 394×X4+1. 394×X5-0. 141 ×X6+6. 431×X7+7. 269×X8-4. 575×X9-1. 162×X10 (Y: areas broken out next year; X,: lowerest temperature of current year; X2: relative humidity of last February; X3: relative humidity of last November; X4: relative humidity of last December; X5; rainfall of current April; X6: rainfall of current May; X7: temperature of last August; X8: temperature of last September; X9: temperature of last November; X10: temperature of last December). Meanwhile, the monitoring adults emergence and disturbing copulating were performed using known sex lure of C. dahurica.In severe aggressed stands, the control effect reached about 90% after controlled by biotic or resemble biotic pesticide with high effect, low toxicity and none social effect of pollution such as AV Bacteriophage , 1.2% matrine and nicotine etc..