Study On Pine Sawfly's Pathogenic Microorganisms

In the study naturally died larva of Diprion nanhuaensis were collected twice. The virus was identified to be nuclear polyhedrosis virus. The bacilliform virus particle in inclusion body appears single nucleocapsid polyhedrosis virus (SNPV) under electron microscopy. The structure of inclusion body appears polyhedron and close to rotundit, and the length of diameter of inclusion body is 0.5~1.0μm, a little proportion of them show anomalistic form. There are many bacilliform virus particles in one inclusion body. Six virus particles in one inclusion body take up a large proportion and single virus particle only takes up a small proportion, the length of virus particle is 125~200nm, and the the length of diameter of virus particle is 25~30nm. The virus release virus particles in virus inclusion body under slightly alkaline environment. The bacilliform virus particle ranged (20～30)nm×(80～320)nm. The virus was named DnNPV.The virulence of Nuclear PolyhedrosisVirus of Diprion nanhuaensis separated from the first collection was tested in laboratory. The results showed,①the proofread mortality of the 2~3 instar larvae of Neodiprion xiangyunicus reach 58.8% after infected by the virus,and the concentration is 3.9×108PIB·mL-1 sixteen days later, at the same time, the proofread mor- tality was very significant. However, the 5~6 instar larvae of Neodiprion xiangyunicus had no reactivity to the virus;②the virus infected the 2~3 instar larvae of Diprion nanhuaensis with 2.0×108, 2.0×107, 2.0×106(spores)·mL-1 respectively, the proofread mortality had homocer- cal relationship with concentrations, and the mortality rate was of significantly difference.Pathogenic microorganisms of pine sawfly cocoon was investigated, the result showed the main pathogenic microorganisms was fungus, and the fungus autoeciousness ratio of pine sawfly cocoon was very high. The cocoon of Pristiphora erichsonii parasited by fungus reached 41.8%. Five fungus were tested with 2~3 instar larvae of Arge geei, and the concentration of the fungus was 1.0×108 spore·mL-1, the five fungus were: NG-1(separated from Pristiphora erichsonii in Guyuan, Ningxia), NG-2(separated from Pristiphora erichsonii in Guyuan, Ningxia), SH-1(separated from Pristiphora erichsonii in Huoditang, Qinling mountain), GT-1(separated from Pristiphora erichsonii in Tianshui, Gansu), YB-1(separate from Neodiprion xiangyunicus in Yunnan),and the the proofread mortality of each fungi strains were: GT-1= 91.0﹪, SH-1= 82.8﹪, YB-1= 75.0﹪, NG-2= 73.2% and NG-1= 69.5%。...