Vertical migration of adultIxodes rubicundus, the Karoo paralysis tick (Acari: Ixodidae)

✍ Scribed by Agnes Snyman; L. J. Fourie; D. J. Kok; I. G. Horak

• Publisher: Springer Netherlands
• Year: 1994
• Tongue: English
• Weight: 565 KB
• Volume: 18
• Category: Article
• ISSN: 0168-8162
• DOI: 10.1007/bf00055034

✦ Synopsis

Mortality due to Karoo paralysis amongst livestock is of considerable economic importance in South :-kfrica. 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 subsuates were investigated under controlled conditions. Vertical migration of adult Ixodes rubicumtus 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°C than at 21=C. More female than male and mole older than younger ticks migrated vertically in all experiments. The results of this study contribute towards an understanding of the epidemiology of Karoo paralysis.