Evaluation of the effects of infection by different entomopathogenic nematodes and chemical pesticides on Bradysia odoriphaga
Author of the article:WU Hai-Bin1** XIN Li1 GONG Qing-Tao1 ZHANG Kun-Peng1CAO Guang-Ping2 SUN Rui-Hong1***
Author's Workplace：1. Shandong Institute of Pomology, Taian 271000, China; 2. Shandong Seed Group CO. LTD, Jinan250100,China
Key Words：entomopathogens nematodes, chemical pesticides, Bradysia odoriphaga, combination
Abstract：[Objectives] To increase the effectiveness of controlling Bradysia odoriphaga with entomopathogens nematodes, and to screen pesticides as synergists for entomopathogens nematodes. [Methods] The survival rate and infectivity of three entomopathogenic nematodes (Heterorhabdits bacteriophora Taishan strain H06、Steinernema carpocapsae strain SF-SN and All) was tested after dipping them in three kinds of commonly used pesticides (70% imidacloprid wettable granule agent, 40% chlorpyrifos emulsifying concentrate and 4.5% beta-cypermethrin emulsifying concentrate). Impacts on on 3nd instar larvae of Bradysia odoriphaga of treatment with different combinations of the nematodes and low concentrations of pesticides were determined. [Results] Beta-cypermethrin (2.00、0.40、0.20 and 0.10 µg·mL-1) and imidacloprid (25.00、5.00、2.50 and 1.25 µg·mL-1), had no effect on the survival of the nematodes. The lethality of a concentration of 8.00 µg·mL-1 chlorpyrifos emulsifying concentrate to all three nematodes at was significantly higher than that of the control, and mortality of the three nematode species was significantly different when treated with different concentrations of chlorpyrifos emulsifying concentrate. After 3 d, mortality of B. odoriphaga treated with a combination of low concentration chlorpyrifos (8.00 µg·mL-1), imidacloprid (25.00 µg·mL-1) and beta-cypermethrin (2.00 µg·mL-1) with SF-SN was higher than when treated with any one pesticide alone; lethality being improved by 34.20%, 21.18%, and 54.99% respectively. The mortality of B. odoriphaga treated with the SF-SN-insecticide combination was higher than that of those treated with the other combination. [Conclution] The combination of SF-SN with the three kinds of insecticides appears an effective way of controlling B. odoriphaga.