Snyman A, Fourie L J, Kok D J, Horak I G
Department of Zoology and Entomology, University of the Orange Free State, Bloemfontein, South Africa.
Exp Appl Acarol. 1994 Feb;18(2):101-10. doi: 10.1007/BF00055034.
Mortality due to Karoo paralysis amongst livestock is of considerable economic importance in South Africa. Indications are that the extent of vertical migration of adult ticks, to reach questing positions on grasses, is influenced by sudden climatic changes. Such influences as well as selection of questing substrates were investigated under controlled conditions. Vertical migration of adult Ixodes rubicundus on copper rods was determined in a square metal arena within a closed glass container in a room in which temperature and light could be controlled. Significantly more female and male ticks migrated vertically on 1.5 mm diameter rods than on 4.0 mm rods and on 450 mm long rods than on 100 mm rods. More ticks of both sexes migrated vertically at RH > 80% than at RH < 50% and at 12 degrees C than at 21 degrees C. More female than male and more older than younger ticks migrated vertically in all experiments. The results of this study contribute towards an understanding of the epidemiology of Karoo paralysis.
在南非，家畜因卡鲁麻痹症导致的死亡率具有相当大的经济重要性。有迹象表明，成年蜱垂直迁移到草地的探寻位置的程度受突然气候变化的影响。在可控条件下研究了此类影响以及探寻基质的选择。在一个温度和光照可控的房间内的封闭玻璃容器中的方形金属场地中，测定了成年红硬蜱在铜棒上的垂直迁移情况。直径1.5毫米的棒上垂直迁移的雌蜱和雄蜱明显多于直径4.0毫米的棒，450毫米长的棒上垂直迁移的蜱多于100毫米的棒。相对湿度>80%时垂直迁移的蜱比相对湿度<50%时多，12摄氏度时垂直迁移的蜱比21摄氏度时多。在所有实验中，垂直迁移的雌蜱多于雄蜱，老龄蜱多于幼龄蜱。本研究结果有助于理解卡鲁麻痹症的流行病学。
