Development Of LdNPV Compound Agents And Effects On Pathogenicity Against Gypsy Moth Larvae

In order to improve the pathogenicity of Lymantria dispar nucleopolyhedrovieus?LdNPV?and increase the control effect on the gypsy moth,different kinds of light protector and synergist were selected to determine the pathogenicity of the 2ⁿdd instar larvae and the 3^rdinstar larvae of the gypsy moth through food feeding,and the best combination agent was selected.1.The mortality of Ld NPV cationic compound agent against the 2ⁿdd instar larvae was 43.3%after ultraviolet irradiation for 6h,and the mortality of the 2^ndlarvae of gypsy moth was 31%by Ld NPV alone without UV irradiation.The median lethal concentration(LC₅₀)of of LdNPV cationic compound against the 2ⁿdd instar larva was364.9 OBs/?L.The median lethal time(LT₅₀)was 14.5 days,and and the median lethal concentration of LdNPV alone was 16.6d,.The lethal time was shortened by2.1d.2.The cationic compound had different pupation rate and pupae weight.When the virus concentration was low,the larval pupae weight had no obvious effect.When the virus concentration was high,the male pupa weight decreased with the increase of virus concentration.3.The mortality of the 3^rdd instar larvae of gypsy moth caused by the optimal fluorescent suspension compound was 94.7%,and that of Ld NPV alone to the 3^rdd instar larvae was 17%,which increased the mortality by nearly 5 times.The median lethal concentration(LC₅₀)of optimal fluorescent suspension compound to the 3^rdd instar gypsy noth larvae was 1.2 OBs/?L.4.Fluorescein suspension compound had obvious ultraviolet protection on LdNPV,the mortality of fluorescein suspension compound decreased at different time after irradiation under ultraviolet lamp,but the difference was not significant.The mortality of Ld NPV alone under ultraviolet lamp irradiation for different time was significantly reduced,and the mortality rate was 0 after 16 hours of irradiation,which was significantly different from that of non-irradiated LdNPV,indicating that the photoprotective effect of fluorescein suspension compound on Ld NPV was obvious.