Study On Biological Control Techniques Of Longhorned Beetles In The Coastal Shelterbelt

Coastal shelter forests play a very important role in the forest ecosystems of Zhejiang Province and are also an important part of coastal disaster prevention and reduction systems.However,in recent years,the damage and the impact situation by the beetle pests of coastal shelter forests trees is very serious.In this study,coastal shelter forests in Cixi,Yuyao,Taizhou and Linhai,Daishan County,Zhoushan,and Shengsi County were selected as the research object to investigate the occurrence regularity of longhorn beetles which attacked trees in coastal shelter forests through the investigation of species,and on this basis,we relesased parasites of longicorns,adults and eggs of Dastarcus helophoroides Fairmaire and Scleroderma guani Xiao et Wu,and the use of attractants to trap adults,to carry out biological control tests,the results are as follows:(1)Collected 8 kinds of species of cerambycidae pests belonging to the seven genera of three subfamilies in hazardous test ground coastal shelter forests trees like Salix babylonica L,Casuarina equisetifolia L,Fraxinus chinensis Roxb,Melia azedarach L,Pinus thunbergii Parl and Pittosporum tobira,and so on.Among them,Anoplophora glabripennis Motsch,Anoplophora chinensis Forster and Batocera horsfieldi Hope are dominant species.(2)Selected and released Scleroderma guani Xiao et Wu in coastal shelter forests of Cixi,Yuyao and Wenling to control longicorns,the average reduction rate of the population was 27.26%,31.33% and 38.07%,respectively.The rates are all between 25% and 50% in every sample areas,all have good control effects.(3)The control effect by releasing the adults of Dastarcus helophoroides Fairmaire in the ash grove of Cixi,the willow forest of Yuyao and the goldenrain tree forest in Linhai is better than the eggs,but all of them have obvious control effect.60 days after released adults of Dastarcus helophoroides Fairmaire had average reduction rate of the population in 56.43%,57.48% and 54.07%,respectively,and released 35.14%,40.24% and 36.07% at 60 days after releasing their eggs.(4)During the trapping cycle,the numbers of trapped longicorns in forest areas of different experimental sites varied greatly.In Daishan and Shengsi,we traped 62 and 70 longicorns,respectively,much higher than those in Wenling and Yuyao.The number of Anoplophora chinensis Forster was 103,far higher than the 42 Anoplophora glabripennis Motsch and 25 Paraglenea fortunei Saundeas,the effect of F1 attractant in Anoplophora chinensis Forster is better than other longicorns.In addition,in the process of trapping longicorns,attractants can play a long-term role persistently.