Endris R G, Haslett T M, Hess W R
Plum Island Animal Disease Center, USDA-ARS-NAA, Greenport, NY 11944-0848.
J Med Entomol. 1992 Nov;29(6):990-4. doi: 10.1093/jmedent/29.6.990.
In total, 1,186 second instar Ornithodoros (Alectorobius) puertoricensis Fox second instars were fed on a pig when it had a viremia of 10(5.2) hemadsorption units (HAd50/ml) and 420 second-instar O. puertoricensis were fed on an uninfected pig. Subsequent blood meals for ticks in both groups were from uninfected pigs. The effects of African swine fever virus (ASFV) infection on O. puertoricensis populations were evaluated for the following parameters: mortality; mean time to death; percentage molted per instar; percentage molted to male, female, or subsequent instar; effects on duration of premolt period; and the number of blood meals per instar. The cumulative virus-induced mortality rate for all immature stages (second to fifth instar) of O. puertoricensis that had been fed as second instars on a pig infected with ASFV was 43.2%. In contrast, 23.1% mortality was observed among ticks fed on uninfected pigs. The mortality rate among third instars that fed on the viremic pig was 55.3% versus 4.8% among nymphs fed on normal pigs. One-third to more than one-half of all third, fourth, and fifth instars required at least two blood meals to molt. Mean premolt periods for second, third, fourth, fifth, and sixth instars fed on uninfected pigs were approximately 12, 15, 32, 22, and 14 d, respectively. Mean weights for unfed second to fifth instars, males, and females were: 0.6, 1.0, 1.5, 1.7, 1.5, and 3.1 mg per tick, respectively.
总共，1186只波多黎各钝缘蜱（Alectorobius亚属）二龄若蜱在一头猪出现病毒血症，病毒滴度为10(5.2) 血吸附单位（HAd50/ml）时吸食猪血，另有420只二龄波多黎各钝缘蜱吸食未感染猪的血。两组蜱虫随后的血餐均取自未感染猪。针对以下参数评估非洲猪瘟病毒（ASFV）感染对波多黎各钝缘蜱种群的影响：死亡率；平均死亡时间；各龄期的蜕皮百分比；蜕变为雄蜱、雌蜱或下一龄期的百分比；对蜕皮前期持续时间的影响；以及各龄期的血餐次数。曾在感染ASFV的猪身上作为二龄若蜱吸食猪血的所有未成熟阶段（二龄至五龄）波多黎各钝缘蜱，因病毒诱导的累积死亡率为43.2%。相比之下，在未感染猪身上吸食猪血的蜱虫死亡率为23.1%。在感染病毒血症猪的三龄若蜱中，死亡率为55.3%，而在正常猪身上吸食猪血的若蜱死亡率为4.8%。所有三龄、四龄和五龄若蜱中有三分之一至一半以上至少需要两次血餐才能蜕皮。在未感染猪身上吸食猪血的二龄、三龄、四龄、五龄和六龄若蜱的平均蜕皮前期分别约为12、15、32、22和14天。未进食的二龄至五龄若蜱、雄蜱和雌蜱的平均体重分别为：每只蜱虫0.6、1.0、1.5、1.7、1.5和3.1毫克。
