Trapping And Chemical Control Technology Research On Asian Citrus Psyllid

Asian Citrus Psyllid（Diaphorina citri Kuwayama）,（Hemiptera:Liviidae）,is a worldwide pest of citrus and seriously harmful for citrus production.The Psyllid adults and nymphs cause damage to citrus by severe ingestion of phloem sap and resulting in withered and dried young shoots.The white honeydew from nymphs cause soot and affect the photosynthesis.The more serious damage is that Asian Citrus Psyllid can transmit Candidatus Liberibacter spp.,which is the pathogenic bacteria of Huanglongbing（HLB）disease,which is a devastating threat to the citrus industry around the globe.Current study shows the lure effect of different colored sticky cards,light,odor and chemical control for Asian Citrus Psyllid.The main conclusions are as followed:1.We have evaluated the trapping effect of ten different colored sticky cards against Psyllids through hanging,which includes yellow,white,red,green,green,gray,black,yellow,purple,blue,and pink color traps and the number was 21.83/card·12 day.We found that the yellow sticky card is the best color trap among ten different test colors.We tested the effects of yellow card in different directions,different heights and different spacing to trap psyllids.We found the best results with following trap numbers,28.00/card·12 day in south,36.75/card·12 day at the height of 150cm and 32.33/card·12 day at4 m.Thus,we concluded that hanging yellow sticky card in the south,at the height of 150cm and 4 m spacing could be the best for trapping psyllids.2.We indicated the effect of LED lights of seven different colors including white,yellow,pink,red,purple,green,blue on luring psyllids.In indoor test,we found green and blue LED could lure more psyllids.The percent of green and blue were 35.54%and33.44%,respectively in day time and 34.78%and 32.82%,respectively in night time.On the other hand,simulated net cage environment,the effects of green,white and blue showed significantly best results with 30.04%,28.96%and 25.24%,respectively in daytime and 26.52%,26.67%and 25.12%,respectively in night time.Thus,green and blue were best among other colors for luring psyllids.3.We obtained 22 volatile components of citrus tender shoot through headspace absorb and GC-MS technology and found a mixture which could lure psyllids,in addition to a repellent substance by trend detection and field test.The attractant percent of the mixture was 66.67%（P<0.01）.The number of lured psyllids ranged up to 15.00 on the third day and 23.67 on the fifteenth day in the field,which showed significant difference from control（3.67 on the third day and 6.00 on the fifteenth day）.Afterwards,we found the best primary concentration（without dilution）by using concentration gradient test and we observed that it could trap 30.00 on fifteenth day and 46.00 psyllids on thirtieth day on an average,which shows a significant difference from the other diluted solutions of 10（17.33 on fifteenth day and 33.00 on thirtieth day）,100（11.33 on fifteenth day and 24.00on thirtieth day）and 1000（8.67 on fifteenth day and 18.67 on thirtieth day）times and control（6.00 on fifteenth day and 16.67 on thirtieth day）.The repelling rate of the repellent substance was 66.22%（P<0.01）.The repelling rate of hanging for the single shoot was more than 60%and it could last for 20 days and for the whole tree repelling rate was about 40%and it lasts only for 7 days.We tested the taxis and insecticidal activity against psyllids in 11 kinds of plant source extract.Pyrethrin and Rhizoma Acori Graminei showed obvious repellent effect for Asian Citrus Psyllid with repellence rate of 65.52%and 64.91%（P<0.05）,respectively.While,Pyrethrin,Veratrum,Reed Rhizome,Azadirachtin and Rhizoma Acori Graminei had preferably insecticidal activity,and the LC₅₀ were 2.1192 mg/m L,13.1944 mg/m L,41.2582 mg/m L,67.3664 mg/m L and 62.8961 mg/m L,respectively.4.Through the test of indoor toxicity,48%Clothianidin,45%Chlorpyrifos,10%Cyantraniliprole,20%Dinotefuran indicated the virulence effect for Asian Citrus Psyllid adults and the observed LC₅₀ were 1.4786 mg/L、1.4223 mg/L、1.5985 mg/L、1.4903mg/L,respectively.Later,we developed the application of pesticide spray,soil application with their concentration gradient test,accordingly.We evaluated that 20%Dinotefuran at 150 mg/L and 10%Cyantraniliprole at 100 mg/L as the optimum concentration shows good spraying efficacy against citrus Psyllid in citrus orchard,and soil application of 30%Thiamethoxam with optimum concentration of 100 mg/L was best to control Psyllids.