crimean-congo hemorrhagic fever, thogoto, dugbe, and jos viruses isolated from ixodid ticks in ethiopia.from 1974 through 1976, u.s. naval medical research unit no. 5 isolated 25 strain of tick-borne virus in infant mice from 410 pools containing over 6,000 ticks, and one strain from a bird and one strain from a rodent collected in central and southern ethiopia. of these, 17 were identified as known viruses previously found in west central and east africa. there were 8 strains of jos virus from amblyomma ticks; 7 strains of dugbe virus from a bird, a rodent and from ticks; 1 strains of crimean-con ...197898066
distribution and prevalence of spotted fever group rickettsiae in ticks from south carolina, with an epidemiological survey of persons bitten by infected ticks removed from human hosts were tested for the presence of spotted fever group rickettsiae from 1974 through 1976. spotted fever group rickettsiae were detected in dermacentor variabilis, amblyomma americanum, amblyomma maculatum, and ixodes scapularis. persons from whom positive ticks were removed in 1974 and 1975 were questioned about ensuing illness. eleven of 51 persons from whom rickettsia-positive d. variabilis were removed reported some unexplained combination of symptoms compati ...1978103448
theileria mutans in nigeria.two strains of bovine theileria from northern nigeria were shown to be identical to theileria mutans in the indirect immunofluorescent antibody test. one of the strains was transmitted by the tick amblyomma variegatum; large macroschizonts, typical for t mutans, could be demonstrated in infected cattle. it is concluded from these experiments and from the literature that there is reliable evidence so far for the occurrence in nigeria of only two bovine tehileria species, t mutans and t velifera.1979117536
on the life cycle of theileria velifera (uilenberg, 1964) in the gut and the haemolymph of the tick vector amblyomma variegatum (fabriciu, 1794).the development of theileria velifera in the gut and the haemolymph of the tick vector amblyomma variegatum is described. between days three and eight after repletion various sexual stages are present in the gut of the nymphs. zygotes were detected in the gut on day 14, while undifferentiated kinetes first appeared on day 15. in the haemolymph, differentiated kinetes were observed from day 16 after repletion onwards. zygotes and kinetes were also found after the moult, in the adult tick, for a p ...1979120627
the differential diagnosis of the bovine theilerias of southern is currently thought that the following species or sub-species of theileria occur in cattle in southern africa: theileria parva parva (east coast fever), theileria parva lawrencei (corridor disease), theileria parva bovie (rhodesian theileriosis), theileria mutans proper (transmitted by amblyomma species), so-called theileria mutans (a non-pathogenic species transmitted by rhipicephalus appendiculatus, possibly identical with theileria taurotragi) and theileria velifera. the parasites can be ...1979122000
tick-borne diseases of domestic animals in northern nigeria. ii. research summary, 1966 to 1976.during the first 10 years of its existence, the department of parasitology and entomology of the faculty of veterinary medicine, ahmadu bello university in zaria, nigeria, confirmed or described for the first time the occurrence of 25 different tick-borne parasites of domestic animals in the northern part of the country. most of these organisms occur as inapparent infections but may serve as complicating factors in any adverse host condition. the transmission of babesia bigemina by boophilus dec ...1977339447
studies on theileriidae (sporozoa) in tanzania. vii. additional note on the transmission of theileria parva.rhipicephalus evertsi successfully transmitted fatal east coast fever (theileria parva infection) in one experiment. a second one gave negative results, as did an attempted transmission of t. parva by amblyomma variegatum.1977407682
theileria mutans the infectivity for cattle of parasites derived from prefed amblyomma variegatum nymphs.a steer was infected with theileria mutans (aitong) by application of infected amblyomma variegatum nymphs. uninfected a. variegatum larvae were applied to this steer when piroplasms developed. the resultant (and infected) a. variegatum nymphs were applied to the ears of rabbits. equal numbers of ticks were removed daily from rabbits and ground in eagles minimal essential medium. the infectivity of the supernatant fluid was tested in cattle. the produced supernatant fluids were infective between ...1977414391
prevalence of parasitism by amblyomma americanum on wild turkey poults as influenced by prescribed burning.captive-raised eastern wild turkey (meleagris gallopavo silvestris) poults were allowed to forage on either recently burned plots or on plots that had not been burned during the previous 3 years. following a two hour exposure on the study plots, external parasites were recovered from all poults. the louse (menacanthus stramineus) and the lone star tick (amblyomma americanum) were the only parasites recovered. fifty-nine poults exposed to the burned plots had a significantly (p less than 0.001) l ...1979459047
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 seasona ...1979460821
a bioassay method for the pheromone(s) of the bont tick amblyomma hebraeum koch.a bioassay was developed which enabled the detection of the pheromones of the bont tick (amblyomma hebraeum koch) within 2 hours with a reproducibility of 82 +/- 13%. dried, solvent-extracted ticks were glued onto the shaved backs of rabbits. those ticks to which pheromone extract was subsequently applied strongly attracted females of the same species. in a 2-way choice test a cork disc impregnated with pheromone extract was even more attractive to female ticks than a treated dried tick.1979460823
comparisons of the foveae dorsales in male and female ixodid ticks amblyomma americanum, a. maculatum, dermacentor andersoni and d. variabilis (acari: ixodidae). 1979537001
tick infestations and tick-borne diseases in zimbabwe rhodesia.the distribution of tick species in zimbabwe rhodesia is significantly influenced by land utilization practices. the most commonly occurring species in the over-grazed tribal areas is boophilus decoloratus. by contrast, well-managed commercial farms and ranches support a wide range of tick species, the most important of which is rhipicephalus appendiculatus. until recently tick-borne diseases of cattle were efficiently controlled through dipping. the low incidence of disease was an important fac ...1979553966
studies on the ecology of the tick amblyomma hebraeum koch in the eastern cape province of south africa. ii. survival and development.quantitative data are given on the survival and rate of development of amblyomma hebraeum koch in relation to temperature and humidity, in laboratory and field conditions. by comparison with other ixodid species the developmental periods of a. hebraeum are extremely long. development is most rapid at 30 c, and the duration of the developmental periods increases exponentially with decreasing temperature. oviposition occurs successfully at 15 and 30 c, egg incubation at 20 to 30 c, and larval and ...1977577931
chemoreceptor organs used in detection of pheromone(s) of the tick amblyomma hebraeum (acarina: ixodidae). 1977609070
field trials with pheromone-acaricide mixtures for control of amblyomma bebraeum. 1978627671
effects of gulf coast ticks on blood composition and weights of pastured hereford steers.studies conducted in 1975 and 1976 were made of lightweight herefored steers, pastured on native grass pasture and infested with gulf coast ticks, amblyomma maculatum koch. the effects of tick infestations on the blood composition and weights of steers over an 8-week period were measured each year and compared to tick-free animals maintained similarly. by the end of the 8-week study infested animals averaged 8.21 kg less than control animals in 1975 and 12.42 kg less in 1976. of the blood parame ...1978641677
preparation of primary cultures of tick cells.primary cell cultures were prepared from preimaginal bodies from the nymphal ticks, rhipicephalus sanguineus, dermacentor andersoni, and amblyomma maculatum, and from the hemocytes of late-stage nymphal and adult ticks, ornithodoros coriaceus. the dissection methods for obtaining preimaginal bodies and hemocytes for culture are described. a culture mediu, designated rml 375, was used for both culture methods. primary cultures were established with minimal contamination. preimaginal body cultures ...1978697169
the activity of insect juvenile hormone mimics in larval amblyomma hebraeum koch (acarina: metastriata: ixodidae).a total of 14 insect juvenile hormone mimics was tested for activity in amblyomma hebraeum by exposing newly engorged larvae to filter paper impregnated with hormone mimics. the most active compounds used in this assay were hs 103 (6-ethyl-3-pyridyl geranyl ether; ec50=0,0018 mg/cm2), zr 512 (ethyl 3,7,11-trimethyldodeca-2,4-dienoate; ec50=0,0022 mg/cm2), hs 2 (6-methyl-3-pyridyl geranyl ether; ec50=0,0035 mg/cm2), zr 615 (n-ethyl 3,7,11-trimethyldodeca-2,4-dieneamide; ec50=0,0035 mg/cm2), zr 77 ...1978704043
repeated feeding of amblyomma herbraeum (acarina: ixodidae) immatures on laboratory hosts. host effects on tick yield, engorged weight and engorgement period.rabbits and sheep are unable to acquire a resistance to larvae and nymphs of amblyomma hebraeum. after repeated infestation of hosts there is no progressive decline in either the tick yield or the engorged weight of fed ticks. seasonal fluctuations in engorged weights do occur however, with the weight declining in early to midwinter and increasing in early to midsummer. changes in hose physiology as a result of low temperature acclimatization appear to be responsible for the fluctuations. tick y ...1978722460
resistance to certain organophosphorus ixodicides in the bont tick, amblyomma hebraeum koch, in the republic of south africa and swaziland.a series of in vitro trails confirmed resistance in the three-host tick, amblyomma hebraeum koch, to the organophosphorus ixodicides, dioxathion, chlorfenvinphos, quintiofos, bromophos-ethyl and a dioxathion/chlorfenvinphos combination. the results of a routine survey showed that a resistance factor of greater than 100x was present in the offspring of ticks in six of 115 field isolates tested. these six isolates were confined to the lowveld areas of the province of natal, republic of south afric ...1978752082
proteins and free amino acids in the salivary secretion and haemolymph of the tick amblyomma hebraeum.electrophoretic and chromatographic separations of the salivary secretion of amblyomma hebraeum showed a less complex protein pattern than that of ornithodoros savignyi. a hyaluronidase active component was isolated. the haemolymph protein pattern showed a major protein fraction with a mobility slightly faster than that of bovine serum albumin.1978754123
development of theileria mutants (aitong) in the tick amblyomma variegatum compared to that of t. parva (muguga) in rhipicephalus appendiculatus.a comparison was made between the development of theileria mutans (aitong) in adult amblyomma variegatum ticks and the development of t. parva (muguga) in adult rhipicephalus appendiculatus ticks. both batches of ticks dropped as engorged nymphs from cattle whose intraerythrocytic parasitemias were approximately 40%, and it was thus possible to make a direct comparison of the infection rates produced in their tick hosts in this experiment by the 2 species of theileria. ticks of the 2 batches wer ...1975809568
rocky mountain spotted fever (tick-borne typhus) in south carolina: an educational program and tick/rickettsial survey in 1973 and 1974.because the incidence of spotted fever is increasing in south carolina, campaigns were carried out in 1973 and 1974 to provide the public and medical practitioners, through pamphlets and news media, with information about spotted fever and the ticks which transmit the causative agent, rickettsia rickettsii. people were also invited to save and submit live ticks removed from vegetation, animals and humans, for examination by the hemolymph test. a total of 1,186 ticks consisting of 987 dermacentor ...1975811127
studies on theileriidae (sporozoa) in tanzania. iii. experiments on the transmission of theileria mutans by rhipicephalus appendiculatus and amblyomma variegatum (acarina, ixodidae).the parasite considered to be theileria mutans in east africa could not be transmitted transstadially by rhipicephalus appendiculatus (seven attempts); it was transmitted by amblyomma variegatum in 6 out of 7 experiments. the possibility that the original south african t. mutans, transmissible by r. appendiculatus, and the parasite called t. mutans in east africa, are different species, has to be considered.1976824772
amblyomma loculosum (ixodidae): first record from continental africa. 1977845892
ecology of the tick amblyomma hebraeum koch in the eastern cape province of south africa. i. distribution and seasonal the eastern cape province of south africa larvae of amblyomma hebraeum koch occur in well-drained, shaded habitats, with a ground cover of grass. the life cycle is normally of 3 years duration. peak larval activity occurs in the summer of the 1st year, peak nymphal activity in the spring of the 2nd year, and peak adult activity in the summer of the 3rd year. larval activity shows no direct correlation with macroclimate. adult activity is correlated with, in the following order of signficance, ...1977886412
the influence of adrenergic agonists and their antagonists on isolated salivary glands of ixodid ticks.various drugs elicit fluid secretion by isolated salivary glands of two species of ixodid ticks (dermacentor andersoni stiles and amblyomma hebraeum koch). among catecholamines, the following order of potency was observed: dopamine, epinine, noradrenaline = adrenaline and isoprenaline. the following drugs, in order of potency, were also agonists on this preparation: ergonovine, ergotamine, 6-hydroxydopamine, apomorphine, phenylephrine, norphenylephrine, beta-phenylethylamine, tyramine, d, l-dopa ...1977891618
evidence for an assembly pheromone(s) produced by males of the bont tick, amblyomma hebraeum (acarina: ixodidae). 1977903938
amblyomma inornatum (acarina: ixodidae): natural hosts and laboratory biology. 1977903941
field evaluation of arthropod repellent netting as a ground cloth against ticks.tick repellent, wide-mesh net ground cloths were tested against amblyomma americanum (linnaeus) by the co2 bait technique. two repellents, n,n-diethyl-metatoluamide (deet) and 3 acetyl-2-(dimethyl-5-heptenyl)-oxazoladine, and two netting fabrics were compared. all combinations tested provided over 90% protection. the effectiveness of repellent ground cloths against chiggers is discussed.1976961999
peripheral nervous system of the ticks, amblyomma tuberculatum marx and argas radiatus railliet (acari: ixodoidea).the peripheral nervous system of an ixodid and an argasid tick include the following components: (1) paired optic, cheliceral and pedipalpal nerves and unpaired stomodeal nerve arising from the pre-esophageal portion of the central nervous system (synganglion); (2) 4 pairs of pedal nerve trunks (each with appendicular and hemal branches) and 4 major pairs of opisthosomal nerves (including the paraspiracular, genital, postlateral-myosomal, and ano-myosomal nerves); and (3) the lateral "sympatheti ...1976978369
trypanosomes in amblyomma americanum from oklahoma. 1976978370
accumulating process and concentration ratios of ingested blood meals in larvae and nymphs of ten species of ticks.the accumulating process and concentration ratios of ingested blood meals in the larvae and nymphs of amblyomma testudinarium, haemaphysalis campanulata, h. concinna, h. formosensis, h. hystricis, h. kitaokai, the bisexual and parthenogenetic strains of h. longicornis, h. megaspinosa, and ixodes persulcatus on rabbits and argas japonicus on chickens were comparatively investigated. the larvae and nymphs of the ixodid ticks examined and the larvae of a. japonicus concentrated the ingested blood m ...1976980120
comparative observations on some bionomics of japanese ixodid ticks under laboratory cultural conditions.seventeen species of japanese ixodid ticks of the genera amblyomma, boophilus, haemaphysalis, ixodes, and rhipicephalus were reared in the laboratory under almost the same cultural conditions. their major biological characters, such as feeding, molting, oviposition, and hatching, were summarized in tables. there were some differences in these bionomics among the species. the general characteristics common to all the ticks, except amblyomma testudinarium, were as follows. the feeding period in im ...1976980121
tick paralysis in a sheep caused by nymphs of amblyomma variegatum. a preliminary report. 1976988681
studies on theileriidae (sporozoa) in tanzania. v. preliminary experiments on a new method for infecting ticks with theileria parva and theileria mutans.bovine blood with a high parasitaemia of theileria mutans was injected through the cuticle into fully engorged nymphs of amblyomma variegatum which had recently detached from a rabbit. after moulting, they transmitted this parasite to a susceptible calf. rhipicephalus appendiculatus transmitted theileria parva in the same way, but results were negative with a. variegatum and t. parva. this method of infecting ticks appears promising for the isolation of theileria strains from the field, and migh ...19761006800
[isolation of thogoto virus from amblyomma and boophilus ticks in central africa].a survey has been carried out in the cameroons and the central african republic about the role of the ticks in the ecology of arboviruses in central africa. attempts for virus isolation were made for 12,678 amblyomma variegatum, 3,276 boophilus decoloratus and 1,769 boophilus annulatus, by inoculation into suckling mice. from 968 pools which were inoculated, 20 yielded isolates which were identified to thogoto virus. considering previously published results concerning tick-borne virus isolations ...19761037382
a review of the evidence in retrospect for a rickettsial etiology in bullis fever.the authors have presented evidence through work done 25-30 years ago for the rickettsial etiology of bullis fever, a forgotten epidemic which occurred with over a 1,000 cases among world war ii troops in training at camp bullis, texas. rickettsiae were recovered from blood and lymph nodes of patients and from ticks, amblyomma americanum, collected in the area. all patients gave a history of tick-bites. the human and tick strains of rickettsiae, carried in chick embryo culture and in animal pass ...19751103350
some aspects of the ecology and lifecycle of amblyomma cajennense (fabricius 1787) in trinidad and their influence on tick control measures.the distribution in trinidad of the tick amblyomma cajennense is defined, and the methods used to determine the boundaries of the infested areas are outlined. the relationships between climate, vegetation and husbandry methods and the distribution of the tick are described. monthly tick collections from specific animals to determine exact seasonal variations were not possible but a study was made of the normal life cycle under laboratory conditions, the results being used to assist in interpreti ...19751124964
evaluation of co2-baited traps for survey of amblyomma maculatum koch and dermacentor variabilis say (acarina: ixodidae). 19751159725
the effect of host species on the engorgement, molting success, and molted weight of the gulf coast tick, amblyomma maculatum koch (acarina: ixodidae). 19751159746
arsenic resistance in species of multi-host ticks in the republic of south africa and swaziland.a survey was made in the republic of south africa and swaziland to determine the incidence of arsenic resistance in multi-host ixodid ticks. arsenic resistant strains were found in the following species:- rihipicephalus appendiculatus, rhipicephalus evertsi, rhipicephalus capensis, amblyomma hebraeum and a species of hyalomma, tentatively identified as hyalomma rufipes. strains of haemaphysalis leachi, haemaphysalis silacea and ixodes pilosus were also tested.19751223285
host and distributional records for the tick amblyomma inornatum (banks) (acarina: ixodidae), with descriptions of the immature stages. 19751223295
[the tick amblyomma variegatum (ixodidae), apparently resistant to arsenic, in madagascar]. 19751230882
studies on theileriidae (sporozoa) in tanzania. i. tick transmission of haematoxenus veliferus.haematoxenus veliferus was experimentally transmitted in cattle on two occasions by the tick amblyomma variegatum; transmission was transstadial, from nymph to adult. theileria mutans and cowdria ruminatium were transmitted at the same time. h. veliferus infected at least 15% of red cells in a splenectomized steer and 10% in a normal steer. one experiment on transstadial transmission from larva to nymph was unsuccessful.19761258136
effects of 60co irradiation on amblyomma hebraeum koch, 1844 (acarina: ixodidae).the effects of 60co irradiation on amblyomma hebraeum koch, 1844 were studied by mating normal females to males irradiated to attain dosages of 0, 2, 4, 6 and 8 kilorad. the males of all 5 groups were observed mating 7 days after being placed on the host. the higher the irradiation dosage received by the males, progressively longer were the feeding periods of the females mated with them and fewer completed their engorgement. furthermore, the mass of the females when engorged was lower, fewer lai ...1978750959
actions of some transmitters and their antagonists on salivary secretion in a tick.cholinomimetics (pilocarpine, carbachol, physostigmine, acetylcholine, acetyl-beta-methylcholine) and sympathomimetics (dopamine, epinephrine), when injected into the hemolymph, provoked salivary fluid secretion in the female ixodid tick amblyomma hebraeum koch. atropine, but not tubocurarine or toxiferine, abolished pilocarpine-induced secretion without reducing the response to dopamine. reserpine and guanethidine likewise selectively attenuated pilocarpine-induced secretion. following extirpat ...1978677342
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 w ...19921297956
[attempt to attract amblyomma variegatum (acarina:ixodina) on cattle previously treated with aggregation-fixation pheromones and a pyrethrinoid acaricide].the application of synthetic pheromonal aggregation-attachment compounds or male tick extracts on certain sites of the body of bull calves reared on infested pastures did not induce any attraction of free adults on these sites. previously attached males were more attractive than synthetic pheromones or natural extracts. very small amounts of flumethrin poured directly on testicles or on the dewalp induced a large decrease in the infestation of these sites.19921298024
morphology of the spermatid and spermatozoon of amblyomma hebraeum koch (acarina; ixodidae).spermatids and spermatozoa of amblyomma hebraeum were examined by scanning and transmission electron microscopy as well as by freeze-etch and freeze-fracture techniques. the external surface of the spermatid is smooth except for a rim of two parallel grooves near the anterior apex. this rim probably marks the level at which a cap detaches, permitting extrusion of the inner cord during spermatozoon maturation. both ends of the spermatid are closed, the anterior part being slightly thicker than th ...1978654427
saliva-activated transmission (sat) of thogoto virus: dynamics of sat factor activity in the salivary glands of rhipicephalus appendiculatus, amblyomma variegatum, and boophilus microplus ticks.thogoto (tho) virus is transmitted from infected to uninfected ticks when co-feeding on uninfected guinea-pigs, even though the guinea-pigs do not develop a detectable viraemia. this form of non-viraemic transmission is potentiated by a factor(s) secreted by the saliva of ticks and hence has been termed saliva-activated transmission (sat). the synthesis of the sat factor by the salivary glands of three ixodid tick species was determined by placing uninfected nymphal ticks on guinea-pigs that wer ...19921326431
relative susceptibility of jamaican strains of boophilus microplus, amblyomma cajennense, and anocentor nitens to various acaricides. 1977604370
comparative study of tick burdens in gudali and wakwa cattle under natural infestation in the subhumid highlands of wakwa, cameroon. preliminary observations.the relative resistance to different cattle ticks of gudali and wakwa cattle with different levels of brahman breeding, grazed on natural pastures in the subhumid tropics of wakwa, cameroon, was assessed using pasture tick infestations. the basic design consisted of 5 young bulls of each breed from different sire herds. tick populations were observed in gudali and wakwa bulls over a period of four weeks when the climate was thought to be highly favourable for the free-living stages of ticks. cou ...19921339999
experimental transmission of cowdria ruminantium (rickettsiales) by the american reptile tick amblyomma dissimile koch, 1844.a senegalese isolate of the rickettsia cowdria ruminantium was transmitted transstadially by nymphs of the american reptile tick amblyomma dissimile. only eight nymphs, fed as larvae on a saanen goat reacting to heartwater, were required to transmit fatal heartwater to another susceptible goat. since a. dissimile usually feeds on snakes, iguanas and lizards in central america, the tick is not considered to play a significant role in the transmission of heartwater between ruminants. however, the ...19921395974
laboratory studies on the life cycle of amblyomma marmoreum (acari: ixodidae) on two different hosts.a comparative study was made of the life cycle of the tortoise tick, amblyomma marmoreum koch, on tortoises and guinea pigs under laboratory conditions. at 25 degrees c and 85% rh with natural day length, duration of off-host stages (preoviposition, oviposition, incubation, and premolt) was similar for ticks fed on both hosts. delay in preoviposition (up to 90 d) was observed in some gravid females. larvae, nymphs, and adults had longer feeding periods on tortoises than on guinea pigs. adult fem ...19921404252
immunization of rabbits against nymphs of amblyomma hebraeum and a. marmoreum (acari: ixodidae).himalayan rabbits immunized with homogenates prepared from nymphs of amblyomma hebraeum koch and a. marmoreum koch ticks developed humoral and probably also cell-mediated immunity to their respective homogenates. beta and gamma globulin levels and numbers of eosinophils and neutrophils increased significantly in inoculated rabbits. the recipient animals developed resistance to homospecific nymphal infestations. cross resistance between the two species was not evaluated. nymphs of both species th ...19921404253
comparative infections of epizootic and enzootic strains of venezuelan equine encephalomyelitis virus in amblyomma cajennense (acari: ixodidae).to compare the potential for an enzootic or an epizootic strain of venezuelan equine encephalomyelitis (vee) virus to infect amblyomma cajennense (f.), larval ticks were fed on guinea pigs (strain 13) inoculated with an enzootic viral strain of variant i-e (68u201) or on guinea pigs inoculated with an epizootic strain of variant i-a (trinidad donkey). peak viremias were 10(5.2) plaque-forming units (pfu)/ml and 10(7.3) pfu/ml in guinea pigs infected with enzootic and epizootic viral strains, res ...19921404262
influence of exposure period and management methods on the effectiveness of chickens as predators of ticks infesting cattle.experiments undertaken on rusinga island, kenya, indicated that rhipicephalus appendiculatus (neumann) was the predominant tick consumed on tick-infested cattle by chickens, followed by amblyomma variegatum (fabricius), boophilus decoloratus (koch) and rhipicephalus evertsi evertsi (neumann). the number of ticks consumed by chickens released with cattle in a 3 h release period was not significantly different from ticks consumed in a 4 h release period. in a free management system, chickens 1-3 m ...19921413461
acquired immunity to larvae of amblyomma marmoreum and a.hebraeum by tortoises, guinea-pigs and guinea-fowl.a study of acquired resistance in guinea-pigs, guinea-fowl and tortoises to larvae of the ticks amblyomma hebraeum koch and a.marmoreum koch (acari: ixodidae) showed that repeated infestations of the laboratory host resulted in a 29.3-49.4% reduction respectively in weight of engorged larvae. no resistance was induced in guinea-fowl, the natural host for larvae of both species. a small decline in the mean weight of engorged larvae was observed for both species of ticks after three successive inf ...19921421505
genetic basis for organochlorine resistance in amblyomma variegatum and information on the susceptibility on a. lepidum to organochlorine acaricides. 1979544643
localized tick bite reaction.a woman presented with a localized tick bite reaction. the tick (amblyomma americanum, the "lone star" tick) was still attached to the erythematous, indurated skin of the upper back. after several unsuccessful attempts at removal, a punch biopsy was performed, and the resultant histologic sections incorporated both tick and involved skin. the various systemic and localized tick bite reactions are discussed, as are the diagnostic dilemmas which may arise when the organism is no longer present. pu ...1979477386
comparison of the attachment rates of males of the ticks amblyomma hebraeum and a. variegatum to cattle, sheep and rabbits in the absence of aggregation-attachment pheromone.losses in domestic ruminants caused by heartwater (cowdria ruminantium infection) in zimbabwe and mozambique are greater when the vector is amblyomma hebraeum than when the vector is a. variegatum. it has been suggested that the epidemiology of the disease may be influenced by the rates at which unfed adults of these two tick species attach to uninfested hosts (i.e. in the absence of the male-produced aggregation-attachment pheromone [aap]). in this study we confined unfed males of a. hebraeum a ...19921446569
the identification of a shared immunogen present in the salivary glands and gut of ixodid and argasid ticks.the identification of a 70-kda immunogen present in salivary gland extracts of several ixodid species, namely hyalomma truncatum (sweating-sickness-inducing (ss+) and non-inducing (ss-) strains), hyalomma marginatum rufipes and rhipicephalus evertsi evertsi, is reported. the immunogen was identified by western blots using a monoclonal antibody of the igm isotype directed against a 70-kda immunogen present in the salivary glands of (ss-) female h. truncatum ticks. cross-reactivity with the gut of ...19921446571
the relationship of phosphodiesterase and cyclic amp to the process of fluid secretion in the salivary glands of the ixodid tick amblyomma americanum.phosphodiesterase (pde) activity in the salivary glands of the female. amblyomma americanum decreased as the tick progressed from a slow to a rapid phase of feeding, while the rate of fluid secretion increased when glands were stimulated with cyclic amp and theophylline. dopamine stimulated pde activity and an 'inhibitory' factor was found in glands obtained from rapidly engorging ticks which decreased pde activity. these findings are discussed as they relate to the process of fluid secretion by ...1978212286
parasites of cottontail rabbits of southern illinois.fifteen species of parasites including haemaphysalis leporispalustris, ixodes dentatus, amblyomma americanum, cediopsylla simplex, odontopsyllus multispinosus, cuterebra sp., obeliscoides cuniculi, trichostrongylus calcaratus, trichostrongylus affinis, longistriata noviberiae, dermatoxys veligera, trichuris sp., mosgovoyia sp., taenia pisiformis, and hasstilesia tricolor as well as coccidia oocysts were collected from 96 cottontail rabbits (sylvilagus floridanus) confined to a pen in southern il ...19921491303
tick (acari: ixodidae) attachment cement and salivary gland cells contain similar immunoreactive polypeptides.a specific antiserum (12c) raised to a 90-kda immunogenic component of salivary glands of the tick rhipicephalus appendiculatus recognized similar 90-kda polypeptides from salivary glands of the american dog tick, dermacentor variabilis, and the lone star tick, amblyomma americanum, as well as 70-kda polypeptides in the cement of d. variabilis, a. americanum, and r. sanguineus (brown dog tick). the reduction in size of the polypeptide for these ticks suggests that it is modified in some way duri ...19921495047
feeding efficiency of larval hyalomma truncatum (acari: ixodidae) on hosts previously exposed to ticks.the effect of guinea pig response to feeding larval hyalomma truncatum koch ticks was studied by measuring the percentage of ticks engorging and molting, their engorged weight, and hemoglobin content. four guinea pigs were infested with 100, 200, 400, and 1,000 larvae, respectively, on three occasions at 21-d intervals, followed by a fourth infestation with 500 larvae. during the second, third, and fourth infestations, significantly fewer ticks engorged on each guinea pig than during the first i ...19921495048
na, k-atpase in the salivary gland of the ixodid tick amblyomma hebraeum (koch) and its relation to the process of fluid and ouabain-sensitive atpase activities were determined in the salivary glands of ticks throughout the feeding cycle. activities were very low in unfed specimens. in the glands of feeding females, the activities rose until a maximum was reached for both atpase components at approximately 200 mg. the activities remain low in males throughout the feeding period. these findings are discussed in relation to the fluid secretory process of the salivary glands.1976133818
[isolation of the yellow fever virus from an egg-cluster and the larvae of the tick amblyomma variegatum].the yellow fever virus is isolated in natura from eggs of a tick amblyomma variegatum. it is then isolated from larvae issued from the same egg-cluster and also from blood of a monkey bitten by larvae of the same origin. it is reported that the same virus has been previously obtained from adults of the same species of tick. an acarine appears for the first time as a sylvatic vector and reservoir (at least temporary) of yellow fever.1979117946
amblyomma americanum: area control with granules or concentrated sprays of diazinon, propoxur, and chlorpyrifos. 197657127
ultrastructure of symbiont-like microorganisms associated with the sperm of ixodid ticks.the endospermatophores found in the seminal receptacles of three species of ixodid ticks: hyalomma marginatum, h. dromedarii and amblyomma hebraeum were examined. the seminal receptacles showed the presence of symbiont-like microorganisms in association with the sperm cells. these yeast-like microorganisms represent extracellular symbionts, produced by the male and introduced in the genital system of the female through copulation. the symbionts frequently occur freely in large agglomerations sur ...19921500765
responses of the ticks amblyomma hebraeum and a. variegatum to known or potential components of the aggregation-attachment pheromone. iii. aggregation.ten known or potential components of the aggregation-attachment pheromone (aap) of the ticks amblyomma hebraeum and a. variegatum, as well as mixtures of these components, extracts of prefed males and live prefed males, were tested as aggregation stimulants. in field assays, laboratory-reared unfed male and female ticks were released 20 cm downwind of co2/pheromone release sites; the numbers of ticks that aggregated at the release sites were recorded after 30 min. in a. variegatum, aggregation w ...19921286609
aride virus, a new ungrouped arbovirus infecting amblyomma loculosum ticks from roseate terns in the seychelles. 19761259597
borrelia sp. in ticks recovered from white-tailed deer in alabama.six hundred sixty-five hunter-killed white-tailed deer (odocoileus virginianus) from 18 counties in alabama (usa) were examined for ticks. most of the collections were made at state-operated wildlife management areas. four species of ticks (n = 4,527) were recovered: the lone star tick amblyomma americanum (n = 482); the gulf coast tick a. maculatum (n = 11); the winter tick dermacentor albipictus (n = 1,242); and the black-legged tick ixodes scapularis (n = 2,792). fifty-six percent of the tick ...19921512879
monthly incidence of theileria cervi and seroconversion to babesia odocoilei in white-tailed deer (odocoileus virginianus) in texas.monthly monitoring of fawns collected from an area in texas endemic for theileria cervi and babesia odocoilei showed that transmission of t. cervi occurred during july and august, a time period consistent with the occurrence of amblyomma americanum. seroconversion to b. odocoilei occurred during october to december and possibly continued through january and february. the time of seroconversion was more suggestive of transmission of b. odocoilei by ixodes scapularis than by amblyomma americanum.19921512881
ectoparasites of the blackbuck antelope (antilope cervicapra).fifty-two free-ranging blackbuck antelope (antilope cervicapra) from texas were examined for ectoparasites. two species of sucking lice (anoplura), one species of chewing louse (mallophaga), one species of louse fly (diptera), and three species of ticks (acari) were found. this is the first report of the anoplurans linognathus cervicaprae and l. pithodes from the western hemisphere. the southern deer ked (lipoptena mazamae), the winter tick (dermacentor albipictus), and the rabbit tick (haemaphy ...19921512888
adult amblyomma hebraeum burdens and heartwater endemic stability in cattle.several conclusions of importance to studies on the epidemiology of heartwater were drawn from an investigation in which the numbers of adult amblyomma hebraeum ticks, to which a closed herd of hereford cattle were exposed over a period of 6 1/2 years, were manipulated. with a tick cowdria ruminantium infection rate of 3-5%, an endemically stable situation was created by dipping the herd only when an average of 10 adult male and female a. hebraeum ticks were counted on 10 animals. when the avera ...19921513597
description of aegyptianella botuliformis n. sp. (rickettsiales: anaplasmataceae) from the helmeted guineafowl, numida meleagris.aegyptianella botuliformis n. sp. (rickettsiales: anaplasmataceae) isolated from helmeted guineafowls numida meleagris from the kruger national park is described. the rickettsia occurs within a membrane-bound vacuole in the cytoplasm of erythrocytes with up to 8 organisms in a mature inclusion. the initial body resembles that of aegyptianella pullorum. the tightly packed, sausage-shaped intermediate forms are a distinctive morphological feature, seen as irregular, pleomorphic forms under light m ...19921513599
reproduction in ticks (acari: ixodoidea). 4. effects of mechanical and chemical stimulation on oocyte development in amblyomma americanum. 19751172534
a case of gynandromorphism in amblyomma hebraeum (acari: ixodidae).a gynandromorph specimen of amblyomma hebraeum was found on a goat on which adult ticks were bred in the laboratory.19921552517
use of high-performance liquid chromatography to separate very small quantities of radio-labelled metabolites from biological order to study the absorption, metabolism and tissue distribution of chemicals in cattle ticks amblyomma variegatum, a method of separating and recovering metabolites in picogram quantities was required. a high-performance liquid chromatographic system has been investigated for this purpose, using tritium-labelled amitraz and some potential metabolites. separation was carried out on nucleosil 5 mum no2 bonded phase. interchangeable pre-columns were used to extend the range of compounds which ...1977914943
distribution, density, and lyme disease spirochete infection in ixodes dammini (acari: ixodidae) on white-tailed deer in maryland.a statewide survey of ticks parasitizing white-tailed deer was carried out in maryland during november 1989 to assess the status of the deer tick, ixodes dammini spielman, clifford, piesman & corwin, the major vector of lyme disease in the northeastern united states. ticks were collected from deer carcasses brought in by hunters at 23 check stations (one per county). a total of 3,437 i. dammini were collected from 538 of 1,281 deer (42%), together with 2,013 dermacentor albipictus (packard) and ...19921552529
pig production in the solomon islands. ii. diseases and parasites.a study of diseases and parasites of pigs in the solomon islands during 1967 to 1969 indicated that infectious diseases were of little consequence. four arthropod parrasite species were found: one tick, one louse and two tabanids. the tick (amblyomma cyprium cyprium) was extremely rare. fifteen species of helminth parasites were recorded and of these stephanurus dentatus was the most prevalent. all species were identified except a filariid, of which only the microfilariae were seen.1977910298
transmission of a theileria species to cattle by the ixodid tick, amblyomma cohaerens donitz 1909.amblyomma cohaerens nymphs, which had been collected as engorged larvae from african buffalo (syncerus caffer) in the mara region of kenya, transmitted a theilerial parasite to a steer. macroschizonts were detected in the regional lymph node of this steer 12 days after tick application and were subsequently detected for 3 days at low levels of parasitosis. the macroschizonts were large and had numerous nuclei, being morphologically unlike any other theilerial schizonts described previously from ...1977906088
relationship of the occurrence and function of 2,6-dichlorophenol in two species of amblyomma (acari: ixodidae). 1977886561
laboratory and field observations on anti-tick properties of the plant gynandropsis gynandra (l.) brig.a shrubby plant, abundant in east kenya, gynandropsis gynandra (l.) brig., was shown to exhibit repellent and acaricidal properties to larvae, nymphs and adult rhipicephalus appendiculatus and amblyomma variegatum ticks. all stages of ticks avoided the leaves of the plant and a high percentage of the ticks which were continuously exposed to its leaves died; surviving ticks were weak and inactive but regained activity when exposed to fresh air. the effectiveness of the plant's leaves as a repelle ...19921615623
the microanatomy of the eye of amblyomma americanum (acari: ixodidae) and resultant implications of its structure. 1977886559
egg output in the weights and states of engorgement of amblyomma variegatum (fabr.) and boophilus annulatus (say): (ixodoidea: ixodidae).the relationship between egg output and the weights and states of engorgement of two species of ixodid ticks amblyomma variegtum (fabr.) and boophilus annulatus (say) was studied, using over 3,000 female ticks of different sizes. based on the average weights and numbers of eggs produced, guide indices are provided for the predictability of the oviposition potential in females of different weights. linear correlation was noted between weights of the ticks and the weights and numbers of eggs they ...1977881144
on the use of the scrotum for feeding larval ixodid ticks on hosts.the efficacy of feeding larval stages of amblyomma variegatum, hyalomma rufipes and boophilus decoloratus on the ears and scrotum of sheep is compared. the effect of age of larvae on the number that engorged on the animal was also investigated. a significantly greater number of larvae fed on scrotum than on ears. the greatest number of larvae engorged when they were fed on the scrotum or ear within 1-4 days of hatching. the older the larvae, the less the number that fed. the economic advantages ...1977860573
application of fluorescent antibody technique to determine infectivity rates of amblyomma americanium (l.) (acarina: ixodidae) salivary glands and oral secretions by theileria cervi (piroplasmorida: theileriidae).salivary glands and oral secretion from individual field collected ticks, or ticks infected with theileria cervi in the laboratory, were subjected to fluorescent antibody techniques to determine the reliability of the technique in the identification of t. cervi in either the oral secretion or salivary glands. results indicated that the fluorescent antibody technique can be used with a reasonable degree of success in the identification of infected salivary glands or oral secretion. oral secretion ...1976794455
responses of the ticks amblyomma hebraeum and a. variegatum to known or potential components of the aggregation-attachment pheromone. iv. attachment stimulation of nymphs.ten known or potential components of the aggregation-attachment pheromone (aap) of the ticks amblyomma hebraeum and a. variegatum, as well as a mixture of these components and extracts of prefed males of the two species, were tested as attachment stimulants for nymphs. unfed nymphs were confined in linen bags on the ears of rabbits that had been treated with the test compounds, mixture or extracts; the numbers attached were recorded after 24 h. in a. hebraeum, attachment was induced by four comp ...19921286610
[transovarian passage of dugbe virus in the tick amblyomma variegatum (fabricius)]. 1978719844
tick infestations of white-tailed deer in alabama.four species of ticks were collected from 537 white-tailed deer (odocoileus virginianus), examined during the hunting seasons (november to january) of 1988-89 and 1989-90 at selected locations in alabama (usa). ixodes scapularis was the most common tick recovered (2,060 specimens) and infested 54% of the deer. dermacentor albipictus was the second most frequent tick (1,253 specimens) and infested 15% of the deer. amblyomma americanum was the third most frequent tick (315 specimens) and infested ...19911758026
[asymptomatic carrier state in creole goats and cattle after recovery from cowdria infection in guadeloupe].creole goats and cattle in guadeloupe can be carriers of cowdriosis (heartwater: cowdria ruminantium) after recovery for a period as long as 11 months in goats and 2 months in cattle. the carrier status was demonstrated by feeding amblyomma variegatum nymphs on recovered animals and the resulting adult ticks on susceptible goats. cowdria ruminantium was not detected permanently during the carrier status.19921301623
perception of breath components by the tropical bont tick, amblyomma variegatum fabricius (ixodidae). i. co2-excited and co2-inhibited receptors.wall-pore olfactory sensilla located in the capsule of haller's organ on the tarsus of amblyomma variegatum ticks bear cells responding to vertebrate breath: one of these sensilla contains a co2-excited receptor and a second sensillum has a co2-inhibited receptor. each of these antagonistic co2-receptors, which display typical phasic-tonic responses, monitors a different co2-concentration range. the co2-inhibited receptor is very sensitive to small concentration changes between 0 and ca. 0.2%, b ...19921331433
acaricide susceptibility of amblyomma variegatum (acari:ixodidae) from puerto rico and guadeloupe.base-line data on acaricide susceptibility of larvae and of larvae and nymphs of the tropical bont tick, amblyomma variegatum (fabricius), from puerto rico and guadeloupe were collected on 14 and six compounds, respectively. nymphs 7-8 weeks old from puerto rico and guadeloupe, and larvae 3-4 weeks old from guadeloupe, were exposed for 24 or 48 h to residues of acetone dilutions of technical-grade or commercial formulations of acaricides on disposable glass pipettes. effectiveness of the acarici ...19911773678
resistance of indigenous african cattle to the tick amblyomma hebraeum.field collections of amblyomma hebraeum koch adults from six breeds of cattle were conducted on two farms in the northern transvaal. the density of a. hebraeum adults was highest on simmentaler cows, followed by santa gertrudis, africaner, bonsmara, brahman and nguni. indigenous breeds, namely nguni, bonsmara and africaner, have the highest level of resistance to a. hebraeum. the relationship between tick abundance and the high level of resistance found in the indigenous breeds is discussed.19911773680
perception of breath components by the tropical bont tick, amblyomma variegatum fabricius (ixodidae). ii. sulfide-receptors.wall-pore sensilla in the capsule of haller's organ on foreleg tarsi of the tick, amblyomma variegatum, show multicellular responses upon stimulation with human and bovine breath. filtering breath through charcoal removes the stimulant for some of these receptors. analysis by gas chromatography coupled with olfactory sensillum electrophysiological recordings indicates that an ethanol extract of the breath components trapped on charcoal contains a major stimulant eluting at the same retention tim ...19921432848
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 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 fa ...19911780126
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