Lindsay L R, Mathison S W, Barker I K, McEwen S A, Gillespie T J, Surgeoner G A
Department of Pathobiology, University of Guelph, ON, Canada.
J Med Entomol. 1999 May;36(3):255-62. doi: 10.1093/jmedent/36.3.255.
The impact of microclimate and density of hosts for adult ticks on the density of Ixodes scapularis Say was evaluated within 4 habitats on Long Point, Ontario, from 1989-1992. During the period from May to September, mean weekly vapor pressure deficits were greater within the oak savannah and cottonwood dune habitats than at the maple forest and white pine habitats, which were similar. Vapor pressure deficit was likely the major factor affecting the survivorship of eggs and immature tricks in these habitats. Based on drag sampling, I. scapularis adults demonstrated peak activity in April and October of each year. The mean number of I. scapularis adults collected by dragging during the fall or in the spring did not differ significantly within each habitat. The mean number of adults collected also did not differ among tick cohorts within each habitat; however, significantly more adults were collected within the maple forest than in the white pine habitat. The mean number of I. scapularis adults per white-tailed deer, Odocoileus virginianus (Zimmerman), increased from 1989 to 1991 and then decreased in 1992. Significantly more adult I. scapularis infested deer were observed in 1990 than in 1989. Removal of deer in 1989 and 1990 resulted in a calculated decrease of > 100,000 fed female ticks. Although seasonal variation in microclimate within habitats was closely linked with tick survival and partly explains the differences in abundance of I. scapularis among habitats on Long Point, habitat utilization by deer was also a primary factor governing the local abundance of I. scapularis populations.
1989年至1992年期间，在安大略省长角的4个栖息地内，评估了小气候和成年蜱宿主密度对肩突硬蜱（Ixodes scapularis Say）密度的影响。在5月至9月期间，橡木稀树草原和三角叶杨沙丘栖息地的平均每周水汽压亏缺比枫树林和白松林栖息地更大，而后两者较为相似。水汽压亏缺可能是影响这些栖息地中蜱卵和未成熟蜱存活的主要因素。基于拖拽采样，肩突硬蜱成虫在每年4月和10月表现出活动高峰。在每个栖息地内，秋季或春季通过拖拽收集到的肩突硬蜱成虫平均数量没有显著差异。每个栖息地内不同蜱虫群体收集到的成虫平均数量也没有差异；然而，在枫树林中收集到的成虫明显多于白松林栖息地。每只白尾鹿（Odocoileus virginianus [Zimmerman]）身上的肩突硬蜱成虫平均数量在1989年至1991年增加，然后在1992年下降。1990年观察到受感染的鹿身上的肩突硬蜱成虫明显多于1989年。1989年和1990年捕杀鹿后，经计算，饱血雌蜱数量减少超过100,000只。尽管栖息地内小气候的季节性变化与蜱的存活密切相关，并且部分解释了长角不同栖息地之间肩突硬蜱数量的差异，但鹿对栖息地的利用也是决定当地肩突硬蜱种群数量的一个主要因素。
