Davey Ronald B, George John E, Miller Robert J
USDA, ARS, Cattle Fever Tick Research Lab., Moore Air Base, Bldg. 6419, 22675 N. Moorefield Rd., Edinburgh, TX 78541, USA.
Vet Parasitol. 2006 Jun 30;139(1-3):211-20. doi: 10.1016/j.vetpar.2006.02.027. Epub 2006 Apr 11.
The reproductive fitness of Rhipicephalus (Boophilus) microplus (Canestrini) strains resistant to organophosphate (OP), pyrethroid (P), or formamidine (F) acaricides was compared to an acaricide-susceptible (SUS) strain to determine whether the acquisition of resistance affected reproductive fitness in the resistant strains. The SUS strain females had a 3.0 days preoviposition period, a 12.1 days oviposition period, a 22.5 days egg incubation period, a mean of 3670 eggs per female, and a mean percentage egg hatch of 78.1%, which were all remarkably similar to these same parameters reported for this species throughout the world. The reproductive biology of the P-resistant strain (PYR) and the F-resistant strain (FOR) were, for the most part, similar to those of the SUS strain. In the few instances where statistical differences did occur there was little evidence that the variation had any biological basis that could be attributed to a reduction in fitness related to resistance to P or F acaricides. Although the comparison of reproductive parameters of the OP-resistant strain (OPR) and the SUS strain identified statistical differences between the mean egg incubation and oviposition periods, the magnitude of the differences was not sufficient to conclude that the OPR strain was biologically less fit than the SUS strain. However, the OPR strain produced 30% fewer eggs (2562 eggs per female) than the SUS strain (3670 eggs per female) indicating the acquisition of resistance placed the OPR at a selective disadvantage relative to the SUS strain. This coupled with a lower, though non-significant, egg hatch was used to predict there would be a reduction of at least 34.1% in larval numbers available to potentially re-infest subsequent cattle than were available from the SUS strain. These data may aid the development of management strategies that can be used to control OP-resistant ticks.
将对有机磷（OP）、拟除虫菊酯（P）或甲脒（F）杀螨剂具有抗性的微小扇头蜱（牛蜱）品系的繁殖适应性与杀螨剂敏感（SUS）品系进行比较，以确定抗性的获得是否会影响抗性品系的繁殖适应性。SUS品系的雌性蜱虫产卵前期为3.0天，产卵期为12.1天，卵孵化期为22.5天，平均每只雌性产卵3670枚，平均孵化率为78.1%，这些参数与世界各地报道的该物种的相同参数非常相似。P抗性品系（PYR）和F抗性品系（FOR）的生殖生物学在很大程度上与SUS品系相似。在少数出现统计差异的情况下，几乎没有证据表明这种差异有任何生物学基础可归因于对P或F杀螨剂抗性导致的适应性降低。尽管OP抗性品系（OPR）和SUS品系的生殖参数比较显示平均卵孵化期和产卵期存在统计差异，但差异程度不足以得出OPR品系在生物学上比SUS品系适应性更差的结论。然而，OPR品系产生的卵比SUS品系少30%（每只雌性2562枚卵），这表明抗性的获得使OPR品系相对于SUS品系处于选择劣势。再加上较低（虽不显著）的卵孵化率，据此预测，与SUS品系相比，OPR品系的幼虫数量可能至少减少34.1%，这些幼虫本可用于再次感染后续的牛。这些数据可能有助于制定可用于控制OP抗性蜱虫的管理策略。
