Study On Natural Enemy Complex Of Hyphantria Cunea(Drury) In Shenyang Area

The Hyphantria cunea(Drury)belongs to Lepidoptera,Arctiidae and is a quarantine pest of agriculture and forestry in China,the ecological environment and social and economic development of China has caused serious damage.In order to obtain a more comprehensive understanding of the natural enemy species of fall webworm,to explore the composition of the natural enemy complex of the fall webworm and the interaction between its internal populations,to provide new ideas and methods for biological control of the fall webworm.In this study,the natural enemy complex of fall webworm population in Shenyang area of China was studied,the main results of the study are as follows:1.A survey of the natural enemies of the fall webworm in Shenyang showed that there were at least 33 species of natural enemies in the area.Among them,parasitic natural enemies 14 species and 1 kinds of epiparasitism hyperparasitism natural enemies.This includes 8 parasitic wasps and 6 parasitic flies.The dominant population of parasitic natural enemy complexes is Cotesia gregalis Yang et You> Compsilura concinnata(Meigen)> Chouioia Cunea Yang.There are 19 species of predatory predators,including 7 predatory insects and 12 species of spiders.Among them,the dominant population of predatory natural enemy complexes is only Ebrechtella tricuspidata(Fahricius),but in the case of predatory insects,Harmonia axyridis Pallas and Chrysopa Formosa Braue has a strong predatory ability to the fall webworm.For the first time in China,Enicospilus kigasirae(Uchida),Bessa Remota(Aldrich)and Phebellia Nigripalpis(Robineau-Desuoidy)3 species of natural enemies can be parasitic fall webworm larvae,and for the first time found 1 species of fall webworm epiparasitism hyperparasitism natural enemy(Trigonalyidae sp.),the natural enemy is parasitic in the fall webworm parasitic fly pupa.2.Through the analysis of natural enemy diversity indexes of each generation and insect state of fall webworm,it is found that:(1)The dominant population of the natural enemy complex of the fall webworm in Shenyang area,Cotesia gregalis Yang et You,Compsilura concinnata(Meigen)and Chouioia cunea Yang,was no significant correlation.(2)The comprehensive evaluation and sequencing of natural enemy complexes of fall webworm in each generation and insect period,the 2nd generation larvae period of the fall webworm in the 2018 > the 2nd generation larva period of the fall webworm in 2017 > the 1th generation larval period of the fall webworm in the 2018.The results showed that the natural enemy complex of fall webworm had a high degree of compound in larval stage and the highest degree of compound in the 2nd generation larval stage.3.Through the study of the predatory behavior,predatory ability and predatory function of the eggs and larvae of the fall webworm by the Chrysopa formosa Brauer and the Harmonia axyridis(Pallas),it was found that: The predatory function of the 3-age larvae C.formosa and the 4-age larvae and adults of the H.axyridis were in accordance with the Holling? disk equation for the 1-age larvae of the fall webworm.And obtained by the disk equation,the maximum predation of 1-age larvae of fall webworm was 49.47·d-1,which was higher than the theoretical day maximum predation of 3-age larvae of C.formosa and 4-age larvae of H.axyridis.