Leprince D J, Lane R S
Department of Environmental Science, Policy and Management, University of California, Berkeley 94720-3112, USA.
J Med Entomol. 1996 May;33(3):355-60. doi: 10.1093/jmedent/33.3.355.
The dusky-footed woodrat, Neotoma fuscipes Baird is a natural reservoir of the Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner, in California. To investigate the potential of host-targeted insecticide to control the tick vectors of B. burgdorferi, permethrin-impregnated or untreated cotton balls were distributed in metal cylinders as potential nesting material adjacent to 95 woodrat houses in chaparral-covered rangeland. Laboratory experiments demonstrated that adult woodrats would enter the cylinders and construct nests from permethrin-treated or untreated cotton. The residual concentration of permethrin did not vary significantly during an 11-mo period and remained > 60% of the registered insecticidal formulation (7.5% [AI] by cotton weight). The abundance of 4 species of ticks (Ixodes neotomae Cooley; the western blacklegged tick I. pacificus Cooley & Kohls; I. woodi Bishopp; and the Pacific Coast tick, Dermacentor occidentalis Marx) infesting woodrats was similar in the treatment and control areas. Although > 90% of the cotton disappeared from the metal cylinders in both areas, examination of 8 active woodrat houses revealed that small amounts of cotton had been incorporated into the nest cups of only 25%. In contrast, the abundance of the flea Orchopeas sexdentatus (Baker) decreased significantly in the treatment area only. Spirochetes were not detected in 168 adult O. sexdentatus fleas that had fed on spirochetemic woodrats, which demonstrates that this flea is an inefficient host of B. burgdorferi. We conclude that the use of permethrin-impregnated cotton as potential nesting material is ineffective for controlling ticks associated with the dusky-footed woodrat in brushlands, but this methodology may be useful for reducing populations of sylvatic fleas.
暗足林鼠（Neotoma fuscipes Baird）是加利福尼亚州莱姆病螺旋体——伯氏疏螺旋体（Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner）的天然宿主。为了研究以宿主为目标的杀虫剂控制伯氏疏螺旋体蜱媒的潜力，将氯菊酯浸渍或未处理的棉球作为潜在筑巢材料分布在金属圆筒中，放置在矮橡树林覆盖的牧场中与95个林鼠窝相邻的位置。实验室实验表明，成年林鼠会进入圆筒，并使用经氯菊酯处理或未处理的棉花筑巢。在11个月的时间里，氯菊酯的残留浓度没有显著变化，仍保持在登记杀虫制剂（按棉花重量计7.5%[有效成分]）的60%以上。在处理区和对照区，侵袭林鼠的4种蜱（新林鼠硬蜱Ixodes neotomae Cooley；西部黑腿蜱I. pacificus Cooley & Kohls；伍迪硬蜱I. woodi Bishopp；以及太平洋沿岸蜱Dermacentor occidentalis Marx）的丰度相似。尽管两个区域中超过90%的棉花从金属圆筒中消失，但对8个活跃的林鼠窝进行检查发现，只有25%的巢杯中有少量棉花被纳入。相比之下，仅处理区的跳蚤六齿栉眼蚤（Orchopeas sexdentatus (Baker)）的丰度显著下降。在以螺旋体血症林鼠为食的168只成年六齿栉眼蚤中未检测到螺旋体，这表明这种跳蚤是伯氏疏螺旋体的低效宿主。我们得出结论，使用氯菊酯浸渍的棉花作为潜在筑巢材料对控制灌丛地中与暗足林鼠相关的蜱无效，但这种方法可能有助于减少野生跳蚤的数量。
