The distribution and variation of Ixodid ticks in Matabeleland region Zimbabwe

Abstract

Ticks have been known to cause severe economic losses due to cattle deaths, low milk production, poor beef quality and poor hide quality. To inform control strategies, it is necessary to carry out tick surveys to determine tick species present in Matabeleland as well as determine their distribution in the region. A total of 119 cattle were sampled from seven sites in   Matabeleland communal and commercial areas, that is, Mangwe, Grills farm, Umguza, Beitbridge, Insiza, Gwanda and Nkayi. Phenotypic identification was done by microscopy and total DNA extraction was performed using the tick legs, which was then followed by Random Amplified Polymorphic DNA (RAPD) analysis to determine genetic variation and DNA polymorphism within the tick population. Of the cattle sampled, 268 ticks were collected and 11 tick species were identified, that is, Amblyomma hebraeum 54%, Hyalomma  truncatum 11%,  Rhipicephalus evertsi evertsi 12%, Rhipicephalus appendiculatus 7.4%, Rhipicephalus (Boophilus) decoloratus 6%, Hyalomma rufipes 3.7%,  Rhipicephalus zambeziensis 1.7%,  Rhipicephalus sanguineus 1.1%,  Rhipicephalus simus 1.1%,  Rhipicephalus lunulatus 0.7% and Amblyomma variegatum 0.7 %. The occurrence of Amblyomma variegatum in this part of the country was a unique finding as the tick is known to be a northern tick and is a rare tick in the southern part of the country. Of the 11 tick species collected, only four tick species were used in the genetic characterization, that is, Hyalomma truncatum, Hyalomma rufipes, Amblyomma hebraeum and Rhipicephalus lunulatus.  Primers OPY-3 and OPX-14 revealed genetic variation amongst the four species showing that RAPDs can be used for determining genetic diversity amongst tick population. This study forms a baseline in further studies on genetic characterization of ticks in Zimbabwe