Department of Entomology, China Agricultural University, Beijing, 100193, China.
J Insect Sci. 2010;10:201. doi: 10.1673/031.010.20101.
tage-dependent dichlorvos and propoxur tolerance in a field population of the German cockroach, Blattella germanica Linnaeus (Blatodea: Blattellidae), was investigated in the laboratory using a topical application bioassay. The results showed the 6 week-old nymphs were more tolerant to dichlorvos and propoxur than the other ages tested. LD₅₀ values of dichlorvos and propoxur for the 6 week-old nymphs were 2.003 µg per insect and 5.296 µg per insect, respectively. Tolerance ratios of 18.55-fold and 4.98-fold for LD₅₀ were obtained from 6-week-old nymphs compared to 4 week-old nymphs. The specific activity of acetylcholinesterase (AChE) from 1 week-old nymphs was the highest among all tested developmental stages of nymphs and adult males and females. The specific activity of AChE decreased significantly with increasing age. The sensitivity of AChE to dichlorvos was the highest with a k(i) value of 3.12 × 10⁴ mol⁻¹min⁻¹ in the last nymphal stage of B. germanica (about 6 weeks-old). The AChE from 4 week-old nymphs was the most sensitive to propoxur, with the highest k(i) value being 2.63 × 10⁵ mol⁻¹ min⁻¹. These results indicated that the different developmental stages and sexes of B. germanica affected the inhibition of AChE by dichlorvos and propoxur.
在实验室中，使用局部应用生物测定法研究了德国蟑螂（Blattella germanica Linnaeus）田间种群对二氯松和丙氧菊酯的时间依赖性耐受性。结果表明，6 周龄若虫比其他测试年龄更能耐受二氯松和丙氧菊酯。6 周龄若虫对二氯松和丙氧菊酯的 LD₅₀ 值分别为 2.003 µg/虫和 5.296 µg/虫。与 4 周龄若虫相比，6 周龄若虫的 LD₅₀ 耐受比为 18.55 倍和 4.98 倍。在所有测试的若虫和成虫雄性和雌性发育阶段中，1 周龄若虫的乙酰胆碱酯酶（AChE）的比活力最高。AChE 的比活力随年龄的增加而显著降低。在德国蟑螂的最后一个若虫阶段（约 6 周龄），AChE 对二氯松的敏感性最高，k(i) 值为 3.12×10⁴mol⁻¹min⁻¹。4 周龄若虫的 AChE 对丙氧菊酯最敏感，k(i) 值最高为 2.63×10⁵mol⁻¹min⁻¹。这些结果表明，德国蟑螂的不同发育阶段和性别会影响 AChE 被二氯松和丙氧菊酯抑制的情况。
