Blue ticks, red-legged ticks, brown-ear ticks, bont ticks, bont-legged ticks. Name a tick and dr Nkululeko Nyangiwe of Stutterheim in the Eastern Cape will probably be able to tell you where in South Africa you will find it, and in what type of vegetation. In the past five years alone, he has painstakingly collected more than 8 000 ticks from cattle on 80 farms across South Africa.
Since 2012, he has worked part-time on his doctorate in Entomology about the distribution and ecology of ticks that are of economic importance to cattle farmers in South Africa and Namibia, and especially also in the Eastern Cape. Dr Nyangiwe is one of 15 students of the Faculty of AgriSciences at Stellenbosch University who will receive their PhD degrees on 6 December during the institution’s graduation week.
Although dr Nyangiwe didn’t have the luxury of dedicating his attention 100% to his studies, he says it did help that issues related to ticks and tick-borne diseases are also part of his day job. This production scientist at the Döhne Agricultural Development Institute in Stutterheim regularly conducts research trials, often with the health of livestock in mind.
Hard work recognised
His diligence has paid off. In September 2017 he received the Bronze Medal from the South African Society of Animal Science (SASAS) at the annual congress held in Port Elizabeth for the meritorious PhD study. In the same month, he presented some of his work on the range expansion of the economically important Asiatic blue tick (Rhipicephalus microplus) at the 3rd International Congress on Parasites of Wildlife held in the Kruger National Park.
Nkululeko says it all started with small-scale studies that he conducted along with colleagues on the ecology and distribution of tick species in the Eastern Cape. “This led to the development of a much larger study that included localities with different agro-ecological zones, including aspects of animal management practices as well as veld management,” he remembers.
Major research findings
One of his first significant findings was that the alien pantropical blue tick (Rhipicephalus microplus), a parasite that originated in Asia has spread to Namibia. It probably piggybacked on livestock imported to South Africa. The tick is linked to tick fever (babesiosis), and gall sickness (anaplasmosis) in cattle.
In his latest paper, published in the Journal of the South African Veterinary Association, he sets out how this tick has slowly but surely expanded its range across South Africa. It was previously thought to occur only in the northern and eastern parts of the country. Nyangiwe’s studies have shown that the pantropical blue tick is now also present throughout the coastal region of the Eastern Cape, as well as the north-eastern region of the Northern Cape. One record was made for the Free State. In the Western Cape, it was found on animals from farms near Wellington, Stellenbosch and Kuilsriver. Many of these animals are part of breeding stocks that are regularly transported to and from the northern grassland and savanna regions of South Africa.
This recent finding means that the pantropical blue tick is now also comfortable in the Albany Thicket vegetation of the Eastern Cape, in the bushveld of the Northern Cape and isolated patches of fynbos in the Western Cape.
“It is possible that the establishment of the Asiatic blue tick in vulnerable environments will result in higher disease incidence and tick-related deaths,” he says. “Several babesiosis-related deaths have already been recorded among vulnerable cattle that have not previously been exposed to this tick species.”
“Ticks and tick-borne diseases have a significant impact on the health of domestic animals worldwide. It is difficult to estimate, but ticks and tick-borne diseases could cost the industry between US$14 and US$19 billion.” He explains the practical implications of his mapping exercise, and the role it plays in the provision of veterinary services. “If one is able to map where certain tick species occur, government and farmers are better able to coordinate control strategies.”
“The observed range changes may be facilitated by the combined effects of environmental adaptability by the tick and the movement of host animals,” he says. “Ticks that used to be found only in colder regions are now also found in warmer locations, and vice versa.” -Press release