刀孢蜡蚧菌油剂对苹果黄蚜的室内毒力测定及田间药效评价

苹果黄蚜Aphis citricola是为害我国苹果、海棠和红叶石楠等果树和观赏植物的重要害虫，已对多种化学农药产生抗性。本研究测定了本实验室研发的刀孢蜡蚧菌Lecanicillium psalliotae YJ007油剂对苹果黄蚜的室内毒力及田间药效。结果表明，YJ007油剂500倍稀释液(4.0×10⁵孢子/mL)处理2、3龄和4龄若虫，药后7 d的累计校正死亡率分别为85.17%、92.94%和97.04%。4龄若虫在处理后2 d行动迟缓，处理后3 d,足和头部出现白色菌丝且大量幼虫死亡，最后菌丝布满试虫体表并产出大量孢子。YJ007油剂500倍稀释液对苹果黄蚜7 d的田间校正防治效果为86.78%。因此，YJ007油剂在苹果黄蚜生物防治中具有极大推广应用价值。

Laboratory toxicity test and field efficacy evaluation of an oil formulation of Lecanicillium psalliotae against Aphis citricola

In China, the spiraea aphid (Aphis citricola) is an important insect pest of fruit trees and ornamental plants, such as apple, crabapple and photinia. The insect pest has developed resistance to various chemical insecticides. In this paper, the laboratory toxicity and field efficacy of YJ007, an oil formulation of Lecanicillium psalliotae developed in our laboratory, against A. citricola was investigated. The results showed that the cumulative corrected mortality of the 2nd-, 3rd-, and 4th-instar nymphs treated with 500 fold YJ007 dilution (4.0×105conidia/mL) were 85.17%, 92.94%, and 97.04% seven days after treatment, respectively. The movement of tested the 4th instar nymphs was slowed down two days after spraying with YJ007 oil formulation, then white hyphae appeared in the foot and head of the nymphs three days after spraying, and a large number of treated aphids died. Finally, the hyphae covered the surface of the insects and produced a great number of spores. In the field experiment, the corrected control efficacy of YJ007 oil formulation on aphids was 86.78% seven days after treatment. Taken together, YJ007 oil formulation has a great application value for the biological control of A. citricola.