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.     

Prevalence and intensity of <Emphasis Type="Italic">Oestrus ovis</Emphasis> in sheep of Shiraz,southern Iran

Two thousand and two heads obtained from slaughtered sheep at the Fars abattoirs (Shiraz, Southern Iran) between April 2006 and April 2007 were examined for the presence of Oestrus ovis larvae. Of the total heads, 995 (49.7%) were infested with O. ovis larvae. O. ovis larvae were observed in both sexes and all age groups in each season of the year. A total of 6264 larvae were collected. The overall larval intensity for the infested sheep was 6.3, with 3.9 in spring, 5.3 in summer, 5.9 in autumn and 7.8 in winter. Prevalence ranged from 23.3% in spring to 80% in winter. Increased infestation was observed in older animals.     

The host status of African buffaloes, Syncerus caffer, for Rhipicephalus (Boophilus) decoloratus

The objective of this study was to assess the host status of African buffaloes, Syncerus caffer, for the one-host tick Rhipicephalus (Boophilus) decoloratus. To this end the R. (B.) decoloratus burdens of ten buffaloes examined in three north-eastern KwaZulu-Natal Province (KZN) nature reserves were compared with those of medium-sized to large antelope species in these reserves and in the southern Kruger National Park (KNP), Mpumalanga Province. The R. (B.) decoloratus burdens of the buffaloes were considerably smaller than those of the antelopes in the KNP, but not those in the KZN reserves. The life-stage structure of the R. (B.) decoloratus populations on the buffaloes, in which larvae predominated, was closer to that of this tick on blue wildebeest, Connochaetes taurinus, a tick-resistant animal, than to that on other antelopes. A single buffalo examined in the KNP was not infested with R. (B.) decoloratus, whereas a giraffe, Giraffa camelopardalis, examined at the same locality and time, harboured a small number of ticks. In a nature reserve in Mpumalanga Province adjacent to the KNP, two immobilized buffaloes, from which only adult ticks were collected, were not infested with R. (B.) decoloratus, whereas greater kudus, Tragelaphus strepsiceros, examined during the same time of year in the KNP harboured large numbers of adult ticks of this species. African buffaloes would thus appear to be resistant to infestation with R. (B.) decoloratus, and this resistance is expressed as the prevention of the majority of tick larvae from developing to nymphs.     

Duration of antibodies against 24 kd protein of Rhipicephalus sanguineus extract in dogs infested with the adult ticks

A 24 kd protein from Rhipicephalus sanguineus (Rs24p) which was common to larvae, nymphs, male and female whole body and salivary gland extract of males and female was detected specifically in the serum from dogs after repeated infestation with adult R. sanguineus. The duration of antibodies against Rs24p in dogs infested with adults was examined by Western blotting analysis. Anti-Rs24p antibody was detected in two of 4 dogs during the period of 40 days in the first infestation. In the second infestation, all dogs showed positive reaction against Rs24p, but the duration of the antibodies varied greatly among the animals.     

Studies on naturally acquired immunity to African ticks. II. Observations on cattle exposed to Rhipicephalus appendiculatus under varying periods of repeated infestations.

Groups of Friesian cattle were infested repeatedly with Rhipicephalus appendiculatus at weekly intervals (eight infestations) and at intervals of 3 weeks (seven infestations) and 6 weeks (seven infestations). The engorgement weight of adults, nymphs and larvae decreased significantly initially, from the second infestation, but rose significantly at later infestations. This rise was more dramatic with larval instars than with any other. A new method for quantifying the resistance status of animals was introduced; this method showed that the resistance acquired by cattle during 6-weekly reinfestations was more stable than that acquired by cattle during weekly and 3-weekly reinfestations. The criteria for assessing natural resistance to ticks was reappraised. These are classified into those serving long- and short-term purposes, and those which have direct and indirect effects. Criteria which could serve long- and short-term purposes include a reduced number of engorged ticks, an increased number of dead male and female ticks, a decreased number of ticks which fed above the critical engorgement weight and an increased number which fed within the pre-mating weight and decreased the number of copulations. The criterion of reduced engorgement weight can serve the short-term purpose only. A new manifestation of resistance to ticks, i.e. decreased moulting weights of nymphs and adults, together with the criterion of decreased egg hatchability, were classified as indirect effects because they were manifested after the ticks had dropped off the resistant cattle.     

Elephant shrews as hosts of immature ixodid ticks

Two hundred and seventy-three elephant shrews, consisting of 193 Elephantulus myurus, 67 Elephantulus edwardii and 13 animals belonging to other species, were examined for ixodid ticks at 18 localities in South Africa and Namibia. The immature stages of Ixodes rubicundus, Rhipicentor nuttalli, Rhipicephalus warburtoni and a Rhipicephalus pravus-like tick were the most numerous of the 18 tick species recovered. Substantial numbers of immature Rhipicephalus arnoldi, Rhipicephalus distinctus and Rhipicephalus exophthalmos were also collected from elephant shrews at particular localities. Larvae of I. rubicundus were most numerous on E. myurus in Free State Province from April to July and nymphs from June to October. Larvae of R. nuttalli were most numerous on these animals during April, May, August and September, and nymphs in February and from April to August. The immature stages of R. warburtoni were collected from E. myurus only in Free State Province, and larvae were generally most numerous from December to August and nymphs from April to October.     

Acquired resistance in rabbits to immature stages of Rhipicephalus evertsi evertsi

Host resistance, accompanied by demonstrable anti-tick antibodies, developed in groups of rabbits that were infested repeatedly with different numbers of Rhipicephalus evertsi evertsi larvae. This resistance was associated with a drastic reduction in the number of ticks that attached but not in the ability to feed and moult by immatures already established on the hosts. Furthermore, resistance reduced to below 50% the proportion of nymphs which emerged from the larvae applied to the three host groups. Nymphs weighing 5–9.9 and 15–19.9 mg moulted to give mainly males or females respectively. The proportion of males and females which moulted from the remaining weight categories was variable. Anti-tick antibodies were detected by enzyme-linked immunosorbent assay as early as 7 days after primary infestation in all hosts. The titres plateaued after the second challenge and declined drastically during the fifth infestation. No appreciable differences were observed in the antibody responses stimulated by different challenge regimens.     

Hosts, seasonality and geographic distribution of the South African tortoise tick, Amblyomma marmoreum

The tortoise tick Amblyomma marmoreum was collected from large numbers of reptiles and other animals during the course of numerous surveys conducted in South Africa. A total of 1229 ticks, of which 550 were adults, were recovered from 309 reptiles belonging to 13 species, with leopard tortoises, Geochelone pardalis being the most heavily infested. The 269 birds sampled harboured 4901 larvae, 217 nymphs and no adult ticks, and the prevalence of infestation was greatest on helmeted guineafowls, Numida meleagris. Only two larvae were recovered from 610 rodents, including 31 spring hares, Pedetes capensis, whereas 1144 other small mammals yielded 1835 immature ticks, of which 1655 were collected from 623 scrub hares, Lepus saxatilis. The 213 carnivores examined harboured 2459 ticks of which none were adult. A single adult tick and 6684 larvae and 62 nymphs were recovered from 656 large herbivores, and a total of 4081 immature ticks and three adults were collected from 1543 domestic animals and 194 humans. Adult male and female A. marmoreum were most numerous on reptiles during January and February, and larvae during March. The largest numbers of larvae were present on domestic cattle and helmeted guineafowls in the Eastern Cape Province during March or April respectively, whereas larvae were most numerous on helmeted guineafowls, scrub hares and the vegetation in north-eastern Mpumalanga Province during May. In both provinces nymphs were most numerous between October and December. Amblyomma marmoreum appears to be most prevalent in the western regions of the Western and Eastern Cape and Free State provinces, and the north-eastern regions of the Northern Cape, KwaZulu-Natal, Mpumulanga and Limpopo provinces.     

Parasites of domestic and wild animals in South Africa. XXI. Arthropod parasites of vaal ribbok, bontebok and scrub hares in the western Cape Province

Vaal ribbok (Pelea capreolus), bontebok (Damaliscus dorcas dorcas) and scrub hares (Lepus saxatilis) were slaughtered in the Bontebok National Park at regular intervals and examined for arthropod parasites. Twelve species of ixodid ticks were recovered; the antelope each harboured 9 species and the hares 11. Rhipicephalus nitens was the most prevalent and most abundant tick. The vaal ribbok also harboured large numbers of Ixodes pilosus and the bontebok fairly large numbers of Rhipicephalus glabroscutatum. The vaal ribbok were infested with 2 lice species and the larvae of 3 oestrid fly species. The bontebok harboured 2 lice species and the larvae of 2 oestrid flies, and the scrub hares were infested with a louse species and a flea species. The host preference and seasonal abundance of some of the parasites were determined.     

Parasites of domestic and wild animals in South Africa. XXXIX. Helminth and arthropod parasites of Angora goats in the southern Karoo

Parasites were collected from 160 Angora goats and kids on the Jansenville Experimental Farm, Eastern Cape Province. Six nematodes were identified to species level and three to generic level. Nematodirus spathiger was the most numerous of the economically important nematodes recovered. It was always present, and fourth stage larvae were collected from untreated goats from August to March, while animals used as tracers also picked up most infection from August to March. Kids born on the farm during October acquired their first nematode infections between 2 and 3 months of age and the intensity of infection increased erratically thereafter to reach a plateau once the kids were 14 months of age. Eight of the nine kids between 3 and 5 months of age and examined between January and March were infected with Moniezia expansa. Five ixodid tick species were collected from the goats of which Rhipicephalus glabroscutatum was the most numerous and prevalent. Its immature stages were present mainly from March to September and adults from July to January. The goats also harboured the biting louse Damalinia limbata and the sucking louse Linognathus africanus. The greatest intensity of infestation with L. africanus occurred on the kids during the first few months of their lives. The larvae of the nasal bot fly, Oestrus ovis were present in kids at 1 month of age, and infestation took place mainly from spring to late summer.     

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.     

Ixodid ticks and lice infesting red duikers and bushpigs in north-eastern Natal.

Eighteen red duikers, Cephalophus natalensis, from the Charters Creek Nature Reserve and 2 from Fanies Island Nature Reserve were processed for arthropod parasite recovery. They harboured 8 species of ixodid ticks and 2 lice species. All were infested with Haemaphysalis parmata and the nymphs of Rhipicephalus muehlensi. Two bushpigs, Potamochoerus porcus, from the Ndumu Nature Reserve, 5 from the Eastern Shores Nature Reserve and 1 from Cape Vidal were examined for ectoparasites. They were infested with 8 ixodid tick species, of which Rhipicephalus maculatus was the most abundant, and with 1 louse species.     

Linognathus weisseri n. sp. (Phthiraptera: Linognathidae) of impalas, Aepyceros melampus: description and biology

The adult male and female and first instar nymph of the sucking louse Linognathus weisseri n. sp. are described. This louse was collected from impalas, Aepyceros melampus, at three localities in Limpopo Province, and at three in Mpumalanga Province, South Africa. Although it usually accounted for only a small proportion of the total louse burden, its overall prevalence exceeded 27%. Its prevalence on adult male impalas (9%) was significantly lower (P = 0.004) than that on adult females (39%), but did not differ among age classes. However, the intensity of L. weisseri infestation was higher on lambs than on yearlings and adults, and peaked on impalas in late winter to early summer. Five species of lice are now known to parasitize impalas and a key for distinguishing adults of these species is included.     

Ixodid ticks of impala (Aepyceros melampus) in Swaziland: effect of age class,sex, body condition and management

Five species of ixodid ticks, Amhlyomma hebraeum, Boophilus decoloratus, Rhipicephalus appendiculatus, R. evertsi evertsi and R. muehlensi, were commonly collected from impala (Aepyceros melampus) in the Mlawula-Mbuluzi-Simunye Nature Reserve and Protected Area complex in north-eastern Swaziland. The prevalence and apparent intensity of infestation of most tick species was greater on yearlings (13-24 months of age) and adults (> 24 months) than on lambs (≤12 months), and on adult males than on adult females. The packed cell volume and marrow dry weight were lower in impala infested with A. hebraeum, and in lambs and adults with moderate to heavy loads of R. muehlensi and/or R. appendiculatus. The age and sex patterns of tick infestation were probably determined by both body condition and host behaviour. The prevalence and apparent intensity of infestation of most tick species was greater in the unmanaged, densely populated area of the reserve than in the managed area from which impala had been culled. This trend was consistent in all months, and in all age classes.     

Birds as hosts of immature ixodid ticks in Free State Province, South Africa

The objective of this study was to determine the species spectrum of ixodid ticks infesting birds in Free State Province, South Africa. To this end a large number of birds belonging to several species were examined for ticks and a total of 180 birds belonging to 39 species at 17 localities were infested, and ticks belonging to eight species were recovered. The immature stages of only two, namely Amblyomma marmoreum and Hyalomma marginatum rufipes, were sufficiently prevalent and numerous to safely assume that they regularly use birds as hosts. Helmeted guineafowls, Numida meleagris, were the most heavily infested and one harboured a total of 319 larvae and four nymphs. Amongst the other species an eastern clapper lark, Mirafra fasciolata, was infested with 69 larvae and a nymph, but no other bird harboured more than 40 ticks. The larvae and nymphs of H. m. rufipes were most numerous on birds from April to August.     

Striped mice, Rhabdomys pumilio, and other murid rodents as hosts for immature ixodid ticks as in the Eastern Cape Province

Striped mice, Rhabdomys pumilio, were trapped over a period of 17 months in the Thomas Baines Nature Reserve, and placed in cages, over water, until all the ticks they harboured had detached. The mice were then returned to the reserve. Four ixodid tick species were recovered from the mice of which the larvae and nymphs of Rhipicephalus follis and Rhipicephalus simus were the most numerous. Most larvae of R. follis detached from mice trapped from March to July, and most nymphs in March and from June to September. Most larvae of R. simus detached from mice trapped from December to March, and most nymphs from January to March and during May and June. Seven ixodid tick species were collected from striped mice, house rats, Rattus rattus, vlei rats, Otomys spp. and Praomys sp. captured in the vicinity of human dwellings or animal holding facilities in the Grahamstown district. The striped mice captured in the Thomas Baines Reserve harboured considerably larger numbers of ticks than any of the rodent species in the more urbanized localities.     

The Relative host status of rock elephant shrews Elephantulus myurus and Namaqua rock mice Aethomys namaquensis for economically important ticks

Several tick species of medical and veterinary importance occur in the southern Orange Free State. The purpose of the present study was to determine the host status of rock elephant shrews ( Elephantulus myurus) and Namaqua rock mice ( Aethomys namaquensis) for these ticks. Infestation levels were used as a criterion. The seasonal abundances of the ticks as well as the effects of landscape topography and sex of the host on infestation levels were also investigated. Incidental observations were made on the pouched mouse (Saccostomys campestris). No adult ticks were recovered from any of these small mammals. Seven tick species were found on the elephant shrews of which only Ixodes rubicundus and Rhipicephalus punctatus occurred in high numbers on a large proportion of the animals. Both these ticks cause paralysis in domestic stock. The Namaqua rock mice harboured eight tick species. Only Haemaphysalis leachi/spinulosa and R. punctatus had a relative abundance exceeding 15%. Three of the 10 pouched mice examined were infested with small numbers of ticks. The 132 rock elephant shrews examined harboured a mean total burden of 121 immature ticks compared to four on each of the 321 Namaqua rock mice. The larvae and nymphs of I. rubicundus occurred mainly in the colder months (April to September), while those of H. leachi/spinulosa preferred the warmer months (October to March). Large numbers of larvae of R. punctatus were present from December to July and nymphs from August to October. Infestation levels of I. rubicundus were consistently higher on animals trapped on southern slopes than on those trapped on northern slopes. The sex of the hosts seemed to have little effect on infestation levels.     

Rhipicephalus sanguineus (Ixodida, Ixodidae) as intermediate host of a canine neglected filarial species with dermal microfilariae

The life cycles of filarioids of dogs presenting dermal microfilariae have been little studied. Following the recent retrieval of dermal microfilariae identified as Cercopithifilaria sp. in a dog from Sicily (Italy), this study was designed to assess the role of the brown dog tick Rhipicephalus sanguineus as an intermediate host of this filarial species. An experimental tick infestation was performed on an infected dog using 300 nymphs of R. sanguineus. Engorged nymphs were collected and examined by both microscopic dissection and molecular analysis at five time points (i.e., the same day of tick detachment and 10, 20, 30 and 50 days post-detachment) to detect the presence and developmental stage of filariae in the ticks. A total of 270 engorged nymphs were collected from the dog and developing filarioid larvae detected in 10 (5%) out of 200 ticks dissected. Infective third-stage larvae were observed in 4 (2%) of the all dissected ticks, 30 days post-detachment. Twelve (6.6%) out of 181 samples molecularly tested were positive for Cercopithifilaria sp. This study demonstrates that nymphs of R. sanguineus feeding on a dog naturally infected by Cercopithifilaria sp. can ingest microfilariae, which develop up to the third infective stage thus suggesting that this tick species might act as an intermediate host of this little known canine filarioid.     

Survey of tick infestation and tick-borne ehrlichial infection of dogs in Ishigaki Island, Japan.

Twelve (54.5%) of 22 free-roaming dogs in Ishigaki Island had tick infestation identified as Rhipicephalus sanguineus. There were 121 ticks recovered and consisted of 28 females, 58 males, 22 nymphs and 3 larvae. Infection of dogs possibly with canine ehrlichial pathogens was examined by both indirect immunofluorescence assay and polymerase chain reaction (PCR). Two dogs of the 13 examined were sero-positive for the human granulocytic ehrlichia agent, and one of two dogs was PCR positive for Ehrlichia platys. This dog had platelet numbers slightly lower than normal value, however, no morulae were found within platelet on peripheral blood smear stained with Giemsa.