Parasites of domestic and wild animals in South Africa. XIII. The seasonal incidence of adult ticks (Acarina: Ixodidae) on cattle in the Northern Transvaal.

Ticks were collected over a period of 13 months, at approximately fortnightly intervals, from 6 Africaner oxen kept on the farm Nylsvley in the Naboomspruit District. The 8 species of Ixodidae collected were, in order of abundance, Rhipicephalus appendiculatus, R. evertsi evertsi, Hyalomma marginatum rufipes, H. truncatum, Amblyomma hebraeum, R. simus, Boophilus decoloratus and Ixodes cavipalpus. The relative abundance of adult ticks of these species, their predilection feeding sites and seasonal fluctuations in numbers are discussed.     

Ticks on crested francolins, Francolinus sephaena, and on the vegetation on a farm in Limpopo Province, South Africa

Ticks were collected at approximately bi-monthly intervals between June 1996 and June 1997 from crested francolins, Francolinus sephaena, and from the vegetation on a mixed cattle and wildlife farm in Limpopo Province, South Africa. The birds were infested with the immature stages of 13 tick species, of which Amblyomma hebraeum, Amblyomma marmoreum and Hyalomma marginatum rufipes were the most numerous and prevalent. Ten ixodid tick species were collected from the vegetation, of which the immature stages of Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) decoloratus and Rhipicephalus evertsi evertsi were the most numerous. No adult ticks were collected from the birds and only two from the vegetation. The restricted home range of crested francolins implies that they could serve as a source of tick infestation only for other animals within the same habitat as the birds.     

Acaricide efficiency of amitraz/cypermethrin and abamectin pour-on preparations in game

The efficacy of an amitraz/cypermethrin pour-on preparation (1% w/v each) was tested against natural tick infestations of buffaloes, eland and blesbok in three separate trials. The eland were also treated with a 0.02% abamectin (w/v) acaricidal pour-on preparation. The amitraz/cypermethrin pour-on was effective against Amblyomma hebraeum, Rhipicephalus evertsi evertsi, Rhipicephalus appendiculatus and Hyalomma marginatum rufipes on the buffaloes. Both acaricides were effective against R. appendiculatus and Rhipicephalus (Boophilus) decoloratus in the eland. The amitraz/cypermethrin acaricide was effective against R. (Boophilus) decoloratus in the blesbok. Ticks can cause damage to the skins, secondary infections, abscesses, anaemia, loss of condition, tick toxicosis and act as vectors of infectious diseases. Introduction of hosts and/or ticks from endemic to non-endemic areas because of translocation of game, may lead to severe losses. The pouron acaricides tested were effective against natural tick infestations and should always be used according to the manufacturer's instructions and efficacy claims.     

Ixodid ticks on indigenous goats owned by small-scale farmers in four communal grazing areas in South Africa

Indigenous goats belonging to small-scale farmers in 4 communal grazing areas in South Africa were sampled for ixodid ticks during the period September 1991 to May 1993. Three of these areas were in the North West Province (Rietgat, Madinyane and Bethany), and one in Mpumalanga Province (Geluk). No tick control was practised unless requested by the owners. Seven ixodid tick species, of which the majority were immature ticks, were collected from the goats in North West Province. Amblyomma hebraeum was the most numerous of these, followed by Rhipicephalus evertsi evertsi and Rhipicephalus appendiculatus. Substantially more ticks were collected from goats at Rietgat than at the Madinyane and Bethany grazing areas. Five tick species were collected at Geluk and R. evertsi evertsi comprised more than 95 % of the total population. At Rietgat and Geluk A. hebraeum nymphs were present on goats throughout the year, while most R appendiculatus nymphs were collected during September and October 1991 and most adults during January and February 1992. At both Rietgat and Geluk most immature R. evertsi evertsi were collected from spring to late summer, while adults were present throughout the year.     

Ticks associated with the three largest wild ruminant species in southern Africa

The objective of this study was to assess the host status of the three largest southern African wild ruminants, namely giraffes, Giraffa camelopardalis, African buffaloes, Syncerus caffer, and eland, Taurotragus oryx for ixodid ticks. To this end recently acquired unpublished data are added here to already published findings on the tick burdens of these animals, and the total numbers and species of ticks recorded on 12 giraffes, 18 buffaloes and 36 eland are summarized and discussed. Twenty-eight ixodid tick species were recovered. All stages of development of ten species, namely Amblyomma hebraeum, Rhipicephalus (Boophilus) decoloratus, Haemaphysalis silacea, Ixodes pilosus group, Margaropus winthemi, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus glabroscutatum, Rhipicephalus maculatus and Rhipicephalus muehlensi were collected. The adults of 13 species, of which the immature stages use small mammals as hosts, namely Haemaphysalis aciculifer, Hyalomma glabrum, Hyalomma marginatum rufipes, Hyalomma truncatum, Ixodes rubicundus, Rhipicephalus capensis, Rhipicephalus exophthalmos, Rhipicephalus follis, Rhipicephalus gertrudae, Rhipicephalus lounsburyi, Rhipicephalus lunulatus, Rhipicephalus pravus group and Rhipicephalus simus, were also collected.     

Reliminary survey of ticks (Acari: Ixodidae) on cattle in Central Equatoria State, Southern Sudan

In a preliminary survey conducted in 2005, the species composition and seasonality of ticks infesting cattle in Central Equatoria State, Southern Sudan was determined. Three locations were selected (Gumbo, Khor Rumla and Nyaing) and surveyed every 3 months. Two cattle herds in each of the three locations were visited four times during the study period. Total body collections of ticks were made from each of five cattle (Nilotic Zebu breed) kept in six different herds. Four tick genera and ten species were identified. The tick species identified were Amblyomma lepidum, Amblyomma variegatum, Boophilus annulatus, Boophilus decoloratus, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus praetextatus and Rhipicephalus sanguineus group. The highest number of ticks was collected in October during the rainy season. A finding of great significance was that R. appendiculatus, vector of East Coast fever, has now firmly established itself throughout the year with possible implications for cattle production in Central Equatoria State.     

Parasites of domestic and wild animals in South Africa. XXV. Ixodid ticks on sheep in the north-eastern Orange Free State and in the eastern Cape Province

The tick burdens of 115 Merino sheep, slaughtered over a period of 15 consecutive months on a farm in the north-eastern Orange Free State, were determined. A total of 7 ixodid and 1 argasid tick species were recovered and the seasonal abundances of Boophilus decoloratus, Hyalomma marginatum rufipes, Margaropus winthemi and Rhipicephalus evertsi evertsi were determined. One hundred and forty-nine Merino sheep were slaughtered over periods varying from 10 to 25 months on 3 farms in Eastern Province Thornveld in the eastern Cape Province and their tick burdens determined. Fourteen ixodid tick species were recovered from these animals and the seasonal abundances of Amblyomma marmoreum, B. decoloratus, Haemaphysalis silacea, R. evertsi evertsi and Rhipicephalus nitens were ascertained. On a farm in Valley Bushveld in the eastern Cape Province, 2 Dorper sheep were slaughtered each month for a period of 24 consecutive months. These 48 sheep harboured 10 ixodid tick species and the seasonal abundances of A. marmoreum, H. silacea, Rhipicephalus appendiculatus and Rhipicephalus glabroscutatum were determined. A total of 17 ixodid tick species, of which 12 had reached the adult stage, where recovered from the sheep on the 5 farms.     

Tick infestation of Borana cattle in the Borana Province of Ethiopia

A study was conducted to identify and determine burdens of ticks infesting Borana cattle in the Borana Province of Ethiopia. Rhipicephalus pulchellus, Rhipicephalus pravus, Rhipicephalus muhsamae, Rhipicephalus praetextatus, Rhipicephalus evertsi evertsi, Amblyomma gemma, Amblyomma variegatum, Amblyomma cohaerens, Amblyomma lepidum, Hyalomma truncatum, Hyalomma marginatum rufipes and Boophilus decoloratus were identified on the cattle. Their burdens ranged from 658-1,554 with a mean of 1,205 ticks per animal. Out of the total 6,025 ticks collected, about 82% were R. pulchellus, followed by R. pravus (about 8%) and A. gemma (5%). The other nine species of ticks accounted for only 5% of the total burdens. It is suggested that a strategic tick control method, aimed mainly at reducing the R. pulchellus burdens, with the objective of allowing a reasonable number of ticks to remain on cattle for the maintenance of endemic stability to tick-borne diseases be instituted.     

Resistance of Brahman and Simmentaler cattle to southern African ticks

Field collections of ticks from two breeds of cattle in the North Western Transvaal showed the common tick species to be Rhipicephalus appendiculatus, Amblyomma hebraeum, Rhipicephalus evertsi evertsi and Hyalomma marginatum rufipes. The number of these ticks was higher on Simmentaler than on Brahman cattle. Correlation was found between the number of ticks on the cattle and their serum gamma globulin levels indicating an increase in the production of antibodies. Similar correlation was also found between the number of ticks on the cattle and the number of eosinophils in their blood. Resistance was probably acquired by the hosts and, it appears, to a higher degree in Brahman than in Simmentaler.     

Tick diversity, abundance and seasonal dynamics in a resource-poor urban environment in the Free State Province

The objectives of this study were to determine the diversity, seasonal dynamics and abundance of ticks infesting cattle in urban, small-scale farming communities in and around Botshabelo and Thaba Nchu in the eastern Free State Province, South Africa. A total of ten cattle, ear-tagged for individual identification, were investigated monthly at each of five localities. Adult ticks were removed from the right hand side of each animal and placed in containers filled with 70% ethanol. They were subsequently identified and their numbers quantified. Immature Otobius megnini were counted but not removed. A total of 244,538 adult ticks of ten different species were collected over the 12-month study period. The tick species, in decreasing order of relative abundance, were: Boophilus decoloratus (87.26%), Rhipicephalus evertsi evertsi (6.86%), Hyalomma marginatum rufipes (2.42%), Otobius megnini (1.85%) Rhipicephalus follis (0.76%), Rhipicephalus gertrudae (0.54%), Rhipicephalus sp. (0.21%), Ixodes rubicundus (0.08%), Hyalomma truncatum (0.01%) and Margaropus winthemi (0.004%). The three most abundant species, namely B. decoloratus, R. evertsi evertsi and H. marginatum rufipes, occurred at all localities but with significant differences in abundance. M. winthemi ticks occurred only in the Thaba Nchu area and were not found at any of the there localities in Botshabelo. Significant differences in tick burdens between the six warm months (September to February) and the six cooler months (March to August) were found for most of the species recorded. Boophilus decoloratus occurred in significantly higher numbers in autumn (March to May) and winter (June to August) compared to spring (September to November) and summer (December to February), with 76.8% of the total B. decoloratus burden occurring during the cooler months.     

Parasites of domestic and wild animals in South Africa. XXIX. Ixodid ticks on hares in the Cape Province and on hares and red rock rabbits in the Orange Free State.

One hundred and seventeen scrub hares, Lepus saxatilis, were examined for ixodid ticks in various regions of the Cape Province. They were infested with 18 tick species and the seasonal abundances of the immature stages of Amblyomma hebraeum, Amblyomma marmoreum, Hyalomma marginatum rufipes, Rhipicephalus appendiculatus and Rhipicephalus glabroscutatum and all stages of Rhipicephalus oculatus and the adults of a Rhipicephalus sp. (near R. oculatus) were determined. Seventy-two scrub hares on 3 farms in the Orange Free State harboured 10 ixodid tick species and the seasonal abundances of the immature stages of H. marginatum rufipes and Hyalomma truncatum and all stages of Rhipicephalus punctatus were determined. Thirty Cape hares, Lepus capensis, examined in the northern Cape Province harboured 5 tick species and the seasonal abundances of the immature stages of H. marginatum rufipes and H. truncatum were determined. Thirty-four Cape hares examined in the south-western Orange Free State carried 6 tick species and the seasonal abundance of immature H. marginatum rufipes was determined on these animals. Twenty-eight Smith's red rock rabbits examined on 2 farms in the south-western Orange Free State were infested with 7 tick species.     

Parasites of domestic and wild animals in South Africa. XXX. Ectoparasites of kudus in the eastern Transvaal Lowveld and the eastern Cape Province.

Sets of four kudus were shot and examined for arthropod parasites at approximately monthly intervals from April 1981 to March 1983 in the southern part of the Kruger National Park, eastern Transvaal Lowveld. These animals harboured 10 ixodid tick species of which Boophilus decoloratus followed by Amblyomma hebraeum were the most abundant. The seasonal abundances of these ticks and of Amblyomma marmoreum, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi and Rhipicephalus zambeziensis were determined. The kudus were also infested with 3 lice and 1 louse fly species, as well as the nymphs of a pentastomid. Sixteen kudus were shot in the Andries Vosloo Kudu Reserve, eastern Cape Province and 9 on an adjacent farm. These animals were infested with 12 tick species. A. hebraeum followed by Rhipicephalus glabroscutatum were the most abundant on kudus in the reserve and R. glabroscutatum followed by Haemaphysalis silacea on the animals on the farm. The seasonal abundances of A. hebraeum, A. marmoreum, H. silacea, R. appendiculatus, R. glabroscutatum and a Rhipicephalus sp. (near R. oculatus) were determined on the kudus in the reserve. The kudus were also infested with 3 lice and 1 louse fly species. Two kudus examined in the Addo Elephant National Park were infested with 6 tick, 1 louse and 1 louse fly species.     

Species composition and geographic distribution of ticks infesting cattle, goats and dogs in a temperate and in a subtropical region of south-east Africa

The species and distribution of ticks infesting cattle, goats and dogs in the eastern region of the Eastern Cape Province, South Africa and Maputo Province, Mozambique were determined from collections made from these animals at 72 localities in the former region and 30 in the latter. Eleven ixodid and one argasid species were recovered in the Eastern Cape Province and 15 ixodid species in Maputo Province. The most common ticks infesting cattle and goats in both provinces were Amblyomma hebraeum, Rhipicephalus (Boophilus) microplus, Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi. The dominant species on dogs were Haemaphysalis elliptica and Rhipicephalus simus. The geographic distributions of the major species and some of the minor species in both regions were plotted. The partial or complete displacement of the indigenous tick Rhipicephalus (Boophilus) decoloratus by the introduced species R. (B.) microplus was a major feature of both surveys.     

Preliminary survey of ticks (Acari: Ixodidae) on cattle in northern Sudan

In a cross sectional survey conducted during the period June 2001 to July 2002, the geographical distribution of ticks on cattle in the Sudan was determined. Seventeen locations were surveyed from Northern, Central, Eastern, Western, Blue Nile and White Nile Provinces. Total body collections of ticks were made from 20 cattle at each location. Four tick genera and 11 species were identified. The tick species collected included Amblyomma lepidum, Amblyomma variegatum, Boophilus decoloratus, Hyalomma anatolicum anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus sanguineus group and Rhipicephalus simus simus. Major ecological changes have occurred due to extensive animal movement, deforestation, desertification and establishment of large mechanized agricultural schemes. These factors have certainly affected the distribution of ticks and tick-borne diseases in the Sudan. The absence of A. variegatum and A. lepidum in northern Sudan was not surprising, since these tick species are known to survive in humid areas and not in the desert and semi-desert areas of northern Sudan. The absence of B. annulatus in northern and central Sudan is in accordance with the finding that this tick species is restricted to the southern parts of the central Sudan. The presence of H. anatolicum anatolicum in Um Benin in relatively high abundance is an interesting finding. The present finding may indicate that the southern limit of this species has changed and moved southwards to latitude 13 degrees N. It is concluded that major changes in tick distribution have taken place in the Sudan.     

The isolation and transmission of an unidentified Babesia sp. to cattle by Hyalomma truncatum Koch 1844

An unidentified Babesia sp. which causes a mild disease in cattle was isolated in a splenectomized ox that received pooled blood from field cattle. That this organism is pleomorphic and resembles Babesia occultans makes it difficult to differentiate between these organisms microscopically. Initially, it was suspected that this Babesia could be B. occultans. Several attempts to transmit this parasite transovarially with Hyalomma marginatum rufipes, the vector of B. occultans, failed. Continued efforts to identify possible vectors, using Boophilus microplus, Rhipicephalus evertsi evertsi and Rhipicephalus appendiculatus, all failed. The only tick thus far identified that could have transmitted the infection transovarially in the adult stage was the two-host tick Hyalomma truncatum.     

The distribution of ixodid ticks (Acari: Ixodidae) in central Ethiopia

Ixodid ticks were collected from domestic animals, mainly cattle, in 11 administrative zones covering 84 districts in central Ethiopia over a period of 2 years (July 1996 to June 1998). Nineteen tick species were identified. Four of these belonged to the genus Amblyomma, one to Boophilus, two to Haemaphysalis, three to Hyalomma and nine to Rhipicephalus. Amblyomma variegatum and Rhipicephalus evertsi evertsi were present in all 11 administrative zones and, with the exception of Afar, Boophilus decoloratus was present in nearly every district in which collections were made. These three species constituted more than 50% of all ticks collected. Amblyomma cohaerens and Rhipicephalus bergeoni were common in the west of the survey region and Rhipicephalus pulchellus in the east. Except for B. decoloratus, of which more females than males were collected, the numbers of male ticks recovered were equal to or exceeded those of females. Mortality in crossbred dairy cattle caused by heartwater (Cowdria ruminantium infection) was reported during the survey period. An integrated approach to tick control is suggested.     

Acaricide resistance profiles of single- and multi-host ticks from communal and commercial farming areas in the Eastern Cape and North-West Provinces of South Africa

A field study (February 2000 to August 2001) was conducted on communal and commercial farms in the Eastern Cape and North-West Provinces of South Africa to detect the levels of tick resistance to commonly used acaricides. The larvae obtained from engorged females of the one-host tick Boophilus decoloratus, the two-host tick Rhipicepalus evertsi evertsi and the three-host ticks Amblyomma hebraeum and Rhipicephalus appendiculatus were tested against various concentrations of amitraz, chlorfenvinphos and cypermethrin using the Shaw Larval Immersion Test method. Ticks from the communal farms showed higher levels of resistance to cypermethrin and some resistance to chlorfenvinphos whilst no resistance was detected against amitraz. However, ticks from commercial farms were equally resistant to amitraz, chlorfenvinphos and cypermethrin. The B. decoloratus populations tested were considerably more resistant to all the acaricides tested than the R. evertsi evertsi, A. hebraeum and R. appendiculatus populations. This supports the hypothesis that single-host ticks develop resistance faster than multi-host ticks. This trend was recorded on most of the farms where single- and multi-host ticks co-existed. It was concluded that the use of acaricides at high frequencies and high concentrations was one of the main causes of tick resistance in the study areas. Possible factors which caused the resistance problems are discussed and acaricide management strategies recommended.     

Efficacy of ivermectin delivered from an intraruminal sustained-release bolus against natural infestations of five African tick species on cattle

The efficacy of ivermectin delivered by an orally administered prototype sustained-release bolus over approximately 90 days was evaluated against natural infestations of five African tick species. Twenty cattle, allocated by restricted randomization based on counts of standard Boophilus decoloratus, were allocated to two groups and were either given an ivermectin bolus or designated as non-medicated controls. All cattle grazed a single pasture of native grasses for 20-40 days before treatment and until trial termination. Starting on Days 27, 40, 68 and 82 after bolus administration, four replicates were confined to individual tick-collection stanchions for 4 to 5-day periods. Ticks recovered from these cattle were counted by species, sex, and stage and degree of repletion; engorged females were weighed and incubated to determine the number which oviposited. For the other replicates, half-body counts of adult ticks (classified by species, sex and degree of repletion by females) were made at 1- and 2-week intervals through Day 90. Among replicates confined to stanchions periodically, fewer (P less than 0.05) engorged adult female B. decoloratus, Hyalomma spp., Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi were collected from bolus-treated cattle than from controls. Numbers of engorged adult female Amblyomma hebraeum were reduced, but differences were not statistically significant (P greater than 0.10). Among cattle maintained continuously on pasture, tick numbers were reduced on the ivermectin-treated groups. A significant (P less than 0.05) treatment by linear time effect was seen for all adult ticks counted except R. appendiculatus. A significant (P less than 0.05) treatment by quadratic time effect was seen for A. hebraeum, B. decoloratus and R. evertsi evertsi, and overall treatment differences were significantly different (P less than 0.05) for these species. The differences tended to increase with time. Except for Boophilus, reductions in tick numbers on treated animals relative to controls were not readily apparent. There were no adverse reactions attributable to ivermectin treatment or the presence of the bolus. Each treated animal retained its bolus throughout the trial, based on metal detection.     

Some helminth and arthropod parasites of the grey duiker, Sylvicapra grimmia

Sixteen grey duikers were culled on the farm Riekert 's Laager in the central Transvaal at irregular intervals from May 1979-March 1981. One trematode species, 3 cestode species and 16 nematode species were recovered from these animals. Of these the following are new helminth records for this antelope: Cooperia hungi , Cooperia neitzi , Cooperia pectinata , Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus falculatus , Trichostrongylus instabilis , Impalaia tuberculata , Nematodirus sp. and Paramphistomum sp. In addition, 6 species of ixodid ticks were collected. These, in order of abundance, were Amblyomma hebraeum (55,9%), Rhipicephalus appendiculatus (36,6%), Rhipicephalus evertsi evertsi (5,1%), Boophilus decoloratus (2,3%), Boophilus microplus (0,05%) and Haemaphysalis sp. (0,05%). Only 60 (2,8%) of the 2 118 ticks that were collected were adults. Of the 3 species of lice that were recovered, Linognathus zumpti zumpti was most abundant (58,9%), but, out of a total of 1 498 collected, 1 496 occurred on 1 animal only. Linognathus breviceps constituted 29,5% and Damalinia lerouxi 11,6% of the total. A total of 277 specimens of the hippoboscid fly Lipoptena paradoxa were collected from 12 of the 16 animals examined. Trends in the seasonal fluctuation of Haemonchus, Trichostrongylus, Impalaia , Lipoptena and the immature stages of Amblyomma and R. appendiculatus are graphically illustrated.     

Parasites of domestic and wild animals in South Africa. XXXI. Adult ixodid ticks on sheep in the Cape Province and in the Orange Free State.

Four to 10 Dorper sheep on each of 12 farms in the Cape Province and 3 farms in the Orange Free State were examined for adult ixodid ticks at approximately 2- to 4-weekly intervals over periods varying from 4 to 18 months, commencing during January, February or April 1989. The farms in the Cape Province were located in the north-west, south-west and south of the province. Those in the Orange Free State were situated in the north-east and in the south. The sheep in the Cape Province harboured 10 species of ixodid ticks and the seasonal abundances of Ixodes rubicundus, Rhipicephalus evertsi evertsi, Rhipicephalus gertrudae and Hyalomma truncatum were determined. The animals in the Orange Free State were infested with 7 tick species and the seasonal abundances of I. rubicundus, R. evertsi and Hyalomma marginatum rufipes were determined.