Department of Entomology, China Agricultural University, Beijing, 100193, China.
Ecotoxicology. 2012 Oct;21(7):1989-97. doi: 10.1007/s10646-012-0933-0. Epub 2012 Jun 28.
Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is currently one of major mirid pests in the Yangtze River and the Yellow River regions in China. Imidacloprid (neonicotinoid) is widely used against pierce-sucking pest insects, including against A. lucorum. In addition to its direct lethal effect, multiple negative sublethal effects may also occur in exposed insects. We assessed potential sublethal effects of imidacloprid on some biological characteristics of A. lucorum with the aim of increasing rational use of imidacloprid against that cotton pest. The lethal toxicity of imidacloprid on adults of A. lucorum was determined in laboratory conditions by a topical application bioassay (LD(50) = 6.70 ng a.i. [active ingredient]/A. lucorum adult). We also estimated a sublethal dose, LD(5) (0.38 ng a.i./adult), a low lethal dose, LD(25) (1.96 ng a.i./adult), and moderate lethal dose, LD(40) (3.97 ng a.i./adult). The sublethal dose of imidacloprid (LD(5)) shortened the pre-oviposition period of females but increased the time required for eggs to develop (i.e. longer embryogenesis). The low lethal dose (LD(25)) also reduced the pre-oviposition period. Females exposed to the LD(40) laid eggs that developed faster but overall percentage of eggs hatching was reduced. LD(25) and LD(40) reduced longevity of males but not of females. In addition, the susceptibility to seven insecticides generally used on Chinese crops was not modified in A. lucorum previously exposed to the LD(25) of imidacloprid. Our results demonstrate sublethal effects of low doses of imidacloprid on A. lucorum (notably on pre-oviposition period and egg development) which may have an impact on population dynamics of this pest.
中华绿盲蝽（Meyer-Dür）（半翅目：盲蝽科）目前是中国长江和黄河流域的主要盲蝽类害虫之一。吡虫啉（新烟碱类）被广泛用于防治刺吸式害虫，包括中华绿盲蝽。除了直接致死作用外，暴露于药剂中的昆虫还可能发生多种负的亚致死效应。我们评估了吡虫啉对中华绿盲蝽某些生物学特性的潜在亚致死效应，目的是提高该棉铃虫害虫对吡虫啉的合理使用。采用浸叶法在实验室条件下测定了吡虫啉对中华绿盲蝽成虫的致死毒性（LD50=6.70ng a.i./A. lucorum 成虫）。我们还估计了一个亚致死剂量 LD5（0.38ng a.i./成虫）、一个低致死剂量 LD25（1.96ng a.i./成虫）和一个中致死剂量 LD40（3.97ng a.i./成虫）。吡虫啉的亚致死剂量（LD5）缩短了雌虫的产卵前期，但延长了卵的发育时间（即胚胎发生时间更长）。低致死剂量（LD25）也缩短了产卵前期。暴露于 LD40 的雌虫产卵更快，但总的孵化率降低。LD25 和 LD40 降低了雄虫的寿命，但不影响雌虫。此外，中华绿盲蝽在先前暴露于 LD25 剂量的吡虫啉后，对七种通常用于中国作物的杀虫剂的敏感性没有改变。我们的研究结果表明，低剂量吡虫啉对中华绿盲蝽（特别是产卵前期和卵发育）具有亚致死效应，这可能对该害虫的种群动态产生影响。
