Dispersal Ability Of Asian Gypsy Moth(Lymantria Dispar Asiatica)

Lymantria dispar(Linnaeus)is one of agriculture and forestry pests in all over the world.In order to prevent and reduce the damage to plants by the spread of gypsy moth,in this paper,on the basis of the habits of gypsy moth and their larvae,the spread ability of gypsy moth were studied.The characteristics of tufts,setae and physical morphology of 1st to 3rd instar of AGM larvae were observed by stereoscopic microscope and electron microscope and the habitats of spinning of the 1st instar larvae were also researched.The passive diffusion distance of AGM larvae were studied by wind power in wind tunnel.The dispersal distance by wind power of the 1 st instar of AGM larvae,the flying distance of the AGM males,the trapping range of the gypsy moth sex pheromone trap,were further researched in the wild.The results are as follows:(1)The result showed that four types of setae were found on Lymantria dispar,namely bubbly setae(spiny setae),micro barbed setae,penniform setae and linear setae.Among them,Micro barbed setae were the longest and bubbly setae(spiny setae)were the most numerous.The relationship between the characteristics of the larvae setae and the diffusion of gypsy moth larvae revealed that there were different levels of positive correlations between the diffusion distance of Lymantria dispar larvae and the ratio of micro barbed setae length and head width,the ratio of penniform setae length and head width,respectively(P<0.05,R=0.79;P>0.05,R=0.32),and there were different levels of negative correlations between the diffusion distance of Lymantria dispar larvae and instars,weights,respectively(P<0.01,R=-0.80;P<0.05,R=-0.72).(2)In the laboratory experiment,the longest spinning of gypsy moth larvae was 350 cm.The average length of silk was(1 84±77)cm,and the diffusion distance of Larvae in wind tunnel as far as 200 cm.There were different levels of positive correlations between the diffusion distance of Lymantria dispar larvae and the length of silk and the wind speed,respectively(P<0.01,R=0.97;P<0.01,R=0.67).(3)The dispersal distance of 1 instar larve of Lymantria dispar was researched in wasteland.The area of the experiment field was 500 m2,and the area of sticky cards was 20 m2.The number of larvae were 1457 and divide to 5 times were released.The conclusion was:The captured number of larvae by sticky cards was 37,the rate of capture was 2.5%.When the maximum wind speed was 5.1 m/s,larvae were driven away from the location with 3 m,and the maximum diffusion distance was about 30 m.(4)From the experiment of the tag to captured AGM,reach the decision was that the sex pheromone trap range was 170 m,and the distance of flying of gypsy moth adult males was at least 170 m in one day.According to the number of gypsy moths that captured by the gypsy moth sex pheromone traps,reaching a conclusion that was the ecdysis peak of gypsy moth that from the end of July to early August.The meteorological factors was influencing the dispersal of AGM,and there was maximum negative correlation between the relative humidity with the quantity of AGM that trapped(R=-0.70,P<0.01).