Fourie L J, Kok O B, van Zyl J M
Department of Zoology-Entomology, University of the Orange Free State, Bloemfontein, South Africa.
Exp Appl Acarol. 1991 Apr;11(1):37-49. doi: 10.1007/BF01193727.
Spatial distribution of the Karoo paralysis tick (Ixodes rubicundus) has been studied in a paralysis enzootic area of the southwestern Orange Free State. Significantly more females than males were collected from the vegetation. Most ticks (99%) used grass as questing sites at a height of approximately 45 cm (range 10-97 cm), which correlates with the size of host animals. No significant differences between the questing height of male and female ticks were evident. The ticks were found on most of the grass species present and, except for the genus Eragrostis, no specific preference was evident. When questing, the capitulum of I. rubicundus is usually (90%) directed towards the ground. Seventy-eight percent of the ticks occurred singly on a specific grassblade or flowerhead. In those cases where two ticks occurred together, no sexual aggregation was evident. Most ticks occurred under or close (mean = 62 cm) to the crown cover of specific shrub or tree species. These plant species were characterized by a dense crown cover with a mat of decaying leaf litter underneath. The preference of the tick for wild olive trees (Olea europaea africana) suggests that, except for the physical characteristics of this tree species, host factors may also be important. Significantly more ticks were distributed on the cooler, more protected southern sides of vegetation in comparison to the northern sides.
在奥兰治自由邦西南部的一个麻痹病地方流行区，对卡鲁麻痹蜱（血红扇头蜱）的空间分布进行了研究。从植被中采集到的雌蜱显著多于雄蜱。大多数蜱（99%）在高度约为45厘米（范围10 - 97厘米）的草丛中作为搜寻宿主的地点，这与宿主动物的大小相关。雄蜱和雌蜱的搜寻高度没有明显差异。在所发现的大多数草种上都能找到蜱，除了画眉草属外，没有明显的特定偏好。搜寻时，血红扇头蜱的假头通常（90%）指向地面。78%的蜱单独出现在特定的草叶或花头上。在两只蜱同时出现的情况下，没有明显的性别聚集现象。大多数蜱出现在特定灌木或树种树冠覆盖之下或附近（平均距离 = 62厘米）。这些植物物种的特点是树冠茂密，下面有一层腐烂的落叶层。蜱对野生橄榄树（非洲油橄榄）的偏好表明，除了该树种的物理特征外，宿主因素可能也很重要。与北侧相比，蜱在植被较凉爽、受保护较多的南侧分布明显更多。
