Study On Biological Characters And Aggregation Behavior Of Dendroctonus Armandi

Dendroctonus armandi is a destructive insect.In recent years,Dendroctonus armandi caused great damage to pinus Montana,seriously affect ecological environment offorest. Because of the complicated living habits,it is very difficult to prevent Dendroctonus armand.The experiment study on life history and habits of Dendroctonus armandi which get from Sichuan,Nanjiang County,Daba tree farm. Use the phloem of healthy, slightly, moderately,seriously damage host and adult posterior intestine secretion to make an "Y" sense of smell instrument determination and EAG on un-mating adult insect.The result can provide a scientific reference to prevent Dendroctonus armandi.1) Dendroctonus armandi place a generation of semi-la or 2 on behalf of the half, mainly overwinter as larvae in the stem phloem, few adults and eggs, in Daba forest of Nanjiang, Bazhong,sichuan province.Overwintering larvae pupated in late March,reached maximum in April to May, adults flied in late April, reached maximum in May to June.Spawning period begins in late April, and new generation of adults flied in July, while some directly went into the overwintering larvae phase. In general, female Dendroctonus armandi invasion first, followed by male for collaboration, damaging the tree trunks from the upper part. Eggs oval, mixed with the sawdust moist dung beetle production in the eating path carved grooves on both sides of jagged; larvae eats horizontal sub-tunnels independently, eating path straight down to a younger age from the previous period to the age distribution of the ladder; old larvae In the sub-tunnel at the end of the pupa into a room near the Oval,1 pupa molt after emergence as adults, remain in the pupal chamber lOd, fully mature, then flew out of holes.2) Dendroctonus armandi is a typical pioneer species of insects which has a strong tendency towards healthy pine, the choice of rate is affected by the host injured levels; while severe harmed pine phloem which still have some lure. Host attractiveness were found in compared trials. According to the intrusion habits of Dendroctonus armandi,the sensitivity to pine health status of females was higher than males, decreased significantly with the damage degree increase; male less obvious, especially for health and mildly injured pine, with closely tend rate, higher than tend rate to the slightly injured than females. Temptation effect of health and mildly injured host and mild intestinal crude extracts was not better than phloem, no temptation effect with male hindgut extracts.3) Dendroctonus armandi on the four kinds of harmful levels of crude extracts of the potential host change and "Y"-shaped nose to measure the host phloem results. Samples of the 4 host dose-response, along with the lower concentration of crude extract decreases the severity of harm, the dose-response curve of the more obvious downward trend. Female hindgut extracts at 100 times the EAG response under the most intense, male hindgut extracts of the EAG response to different dilution of the results are similar.4) This study compared the Dendroctonus armandi various electroantennogram methods of data processing, using each pre-stimulus resting potential correction of the peak potential, and then calculated for each treated sample compared with the relative potential extractants correction, according to the polarization repolarization slope with the slope of the relative potential of the correction filter can reduce the antenna the better activity of the EAG test results.