Zhang Xiaona, Jin Daochao, Zou Xiao, Guo Jianjun
Institute of Entomology, the Provincial Key Laboratory for Mountainous Region Agricultural Pest Management, Guizhou University, Guiyang, China.
Institute of Fungal Resources, Guizhou University, Guiyang, China.
Pest Manag Sci. 2016 May;72(5):1059-66. doi: 10.1002/ps.4233. Epub 2016 Feb 26.
The two-spotted mite, Tetranychus urticae Koch, is one of the most serious mite pests of crops throughout the world. Biocontrol of the mite with fungal agents has long been paid much attention because of the development of insecticide resistance and the severe restriction of chemical pesticides. In this study, the efficacy of submerged conidia of the entomopathogenic fungus Isaria cateniannulata strain 08XS-1 against T. urticae eggs, larvae and female adults was evaluated at different temperatures and humidity in the laboratory and under field conditions.
The results showed that a suspension of 2 × 10(7) submerged conidia mL(-1) caused the highest mortalities of mite eggs, larvae and females (100, 100 and 70% respectively) at 100% relative humidity and 25 °C in the laboratory. In the field experiments against the mites, a suspension of 2 × 10(8) submerged conidia mL(-1) achieved significant efficiency - the relative control effects were 88.6, 83.8 and 83%, respectively, in cucumber, eggplant and bean fields after 10 days of treatment.
The results suggest that the I. cateniannulata strain 08XS-1 is a potential fungal agent, with acceptable production cost of conidia, against T. urticae in the field in an area such as southwestern China with higher air humidity.
二斑叶螨，即朱砂叶螨科赫氏叶螨，是全球最严重的农作物螨类害虫之一。由于抗药性的发展以及化学农药的严格限制，长期以来利用真菌制剂对该螨进行生物防治备受关注。在本研究中，在实验室和田间条件下，于不同温度和湿度下评估了昆虫病原真菌链格孢菌08XS - 1菌株的深层分生孢子对二斑叶螨卵、幼虫和雌成虫的防治效果。
结果表明，在实验室相对湿度100%和25℃条件下，2×10⁷个/mL的深层分生孢子悬浮液对螨卵、幼虫和雌虫的致死率最高（分别为100%、100%和70%）。在田间防治螨类的试验中，2×10⁸个/mL的深层分生孢子悬浮液取得了显著效果——处理10天后，在黄瓜、茄子和豆田中相对防治效果分别为88.6%、83.8%和83%。
结果表明，链格孢菌08XS - 1菌株是一种潜在的真菌制剂，其分生孢子生产成本可接受，在空气湿度较高的中国西南地区等田间对二斑叶螨具有防治效果。
