The Control Of Ambrostoma Quadriimopressum With Entomopathogenic Fungi

Ambrostoma quadriimopressum Motschlsky is a kind of harmful insects that live in the city gardens and parasite in the elm.They mainly eat elm leaves for a living,and they caused serious damage to the elm applied in city gardens.Entomopathogenic fungi has an important role in biological control,most of them have parasitic effects on insects.In this paper,the fungi were purified and identified which is used to control Ambrostoma quadriimopressum Motschlsky and it were isolated from the body surface of the Prathrene tabaniformis.The main results are as follows:Three different morphology of fungi colony were obtained by isolation from 15 Parathrene tabaniformis which collected from the wild.According to the morphology analysis and ITS sequence analysis,these fungi were identified as Beauveria sp.,Fusarium sp.and Mucor sp..By studying the effects of temperature,light quality and ultraviolet conditions on spore germination,the results showed that the optimum germination temperature of Beauveria sp.was 25-30? and the optimum germination temperature of Fusarium sp.was 20-30?.The four colors of light quality which were red,yellow,blue and green have the effect on promoting spore germination of Beauveria sp.;The four kinds of light quality has both promoting and inhibiting effects to the Fusarium sp.Ultraviolet radiation 10min can inhibit the germination of the vast majority of spores.The results of the virulence test of Ambrostoma quadriimopressum showed that the lethal rate of the four strains were about 65%-75%.The results shows that the LT50 of EU1 strain is 4.474d and the lethal of was the fastest.The death rate of AJ9 was the slowest,the speed of AJ2 and AJ5 were not significant.Using spore suspension of EU1 and AJ2 which has different concentrations to deal with the Ambrostoma quadriimopressum Motschlsky,the LC50 of EU1 strain is 5.836×105,the LC50 of AJ2 strain is 2.634×105.the lethal concentration indicates that AJ2 is more sensitive to the Ambrostoma quadriimopressum.In this study,the isolated fungi which were used to control Ambrostoma quadriimopressum were identified by morphological and molecular levels,it can provide reference for the biological control of elm pests.