TitleAbstractYear(sorted ascending)
[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
amblyomma americanum: area control with granules or concentrated sprays of diazinon, propoxur, and chlorpyrifos. 197657127
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
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
amblyomma loculosum (ixodidae): first record from continental africa. 1977845892
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
resistance to toxaphene by the bont tick, amblyomma hebraeum (koch).a series of in vitro and in vivo trials confirmed resistance by the three-host bont tick, amblyomma hebraeum (koch), to toxaphene in the cape, natal and transvaal provinces of the republic of south africa, and in swaziland and transkei. resistance was present in 80 of 97 field strains examined. lindane and ddt resistance was present in the one field strain tested. the results of comparative in vivo hand spraying and plunge dipping trials confirmed those of the larval in vitro tests, thus validat ...1977874951
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
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 microanatomy of the eye of amblyomma americanum (acari: ixodidae) and resultant implications of its structure. 1977886559
relationship of the occurrence and function of 2,6-dichlorophenol in two species of amblyomma (acari: ixodidae). 1977886561
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
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
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
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
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
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
relative susceptibility of jamaican strains of boophilus microplus, amblyomma cajennense, and anocentor nitens to various acaricides. 1977604370
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
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
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
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
[transovarian passage of dugbe virus in the tick amblyomma variegatum (fabricius)]. 1978719844
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
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
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
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
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
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
[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
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
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
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
comparisons of the foveae dorsales in male and female ixodid ticks amblyomma americanum, a. maculatum, dermacentor andersoni and d. variabilis (acari: ixodidae). 1979537001
genetic basis for organochlorine resistance in amblyomma variegatum and information on the susceptibility on a. lepidum to organochlorine acaricides. 1979544643
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
properties of na, k-atpase from the salivary glands of the ixodid tick amblyomma hebraeum. 19806253039
development of theileria mutans (theiler, 1906) in the gut and the haemolymph of the tick amblyomma variegatum (fabricius, 1794).the development of theileria mutans in the gut and haemolymph of its tick vector, amblyomma variegatum, was studied by giemsa-stained smears after the nymphal tick had completed engorgement on parasitaemic calves. sexual stages occurred in the gut between five and seven days after repletion. the zygotes were observed in the gut from day 29 and the kinetes from day 30, i.e. three and four days after the nymphs moulted to adults. from day 34 kinetes were observed in the haemolymph. the development ...19806771935
arbovirus isolations from ixodid ticks infesting livestock, kano plain, a study conducted on the kano plain, kenya, virus isolation attempts were made on ixodid ticks collected, over a 14-month period, from livestock held in family enclosures (bomas) before releasing the animals for daily foraging. 8735 amblyomma variegatum (fabricius) were tested, 98.6% of which were taken from cattle, yielding 36 strains of dugbe (dug), four strains of nairobi sheep disease (nsd), three strains of bhanja (bha), one strain of thogoto (tho) and five strains of virus which could n ...19807210125
the effects of the tick amblyomma hebraeum (acari: ixodidae) on blood composition and weight of rabbits. 19807218269
regulation of body volume by salivation in a tick challenged with fluid loads.injection into the hemolymph of 1.2% nacl, 11.2% sucrose, 2.3% urea (all approximately isosmotic to hemolymph), or distilled water induced salivary fluid secretion in the ixodid tick amblyomma hebraeum koch. saline gave the largest response at high doses. injection of hyperosmotic nacl into the hemolymph did not induce salivation but led to the drinking of distilled water in amounts sufficient to dilute the salt load to isosmolarity. atropine only partially inhibited salivation induced by nacl, ...19807356041
amblyomma americanum: sequential histological analysis of larval and nymphal feeding sites on guinea pigs. 19807364007
performance of ticks fed on rabbits inoculated with extracts derived from homogenized ticks amblyomma maculatum koch (acarina: ixodidae). 19807365638
amblyomma americanum: sequential histological analysis of adult feeding sites on guinea pigs. 19807371734
the ultrastructure of somatic neuromuscular junctions in the tick amblyomma variegatum (fabr.).peripheral nerve axons synapse with somatic muscle fibres in the tropical bont tick amblyomma variegatum. each fibre is innervated by numerous terminals; some of the axons synapse more than once. the nerve terminals on coxal muscle fibres contain agranular electron lucent vesicles 50 to 58 nm in size and have the specialised synaptic membranes characteristic of chemically transmitting nerve-muscle junctions. some of the terminals on trochanteral muscle fibres additionally contain larger vesicles ...19807388905
regional specialization of the sperm membrane in the tick amblyomma hebraeum koch (acari: ixodidae).the spermatozoon of amblyomma hebraeum is about 200 micrometers long and comprises: (l)a thick, club-shaped anterior part, about 20 micrometers long bearing at its apex a "tactile" hemisphere, and (2) an elongated tail-like part, about 180 micrometers long. the surface of the "tactile" hemisphere is covered by numerous bulbous expansions, attached to it by short stalks. the base of the hemisphere is surrounded by a fringe of thin motile processes; the remaining surface of the spermatozoon is cov ...19807388929
epidemiological investigation for arboviruses in jamaica, west indies.arbovirus investigation in jamaica was undertaken between 1960 and 1975. serological studies showed that antibodies to dengue type virus and st. louis encephalitis virus (sle) were prevalent throughout the island for several years. in urban communities, the incidence of dengue antibody was higher than for sle; however, in children under 10 years of age antibody to both viruses was rarely present. in rural areas, sle was prevalent in adults and children. this virus was isolated fom culex nigripal ...19807406115
experimental transmission of african swine fever virus by ornithodoros coriaceus, an argasid tick indigenous to the united states.three ticks, indigenous to the united states, were assessed for their ability to maintain and transmit african swine fever virus (asfv). amblyomma americanum and a cajennense adults and nymphs maintained virus for 4 to 7 days after engorging on infected swine blood; however, virus was not carried through the subsequent molt of nymphs and it was not transmitted vertically to the eggs and larvae of the infected females. on refeeding of the ticks, infection was not transmitted to healthy swine. orn ...19807406278
a critical evaluation of the role played by the red-billed oxpecker buphagus erythrorhynchus in the biological control of ticks.buphagus erythrorhynchus uses 4 feeding methods--scissoring, plucking, pecking and insect catching. during the day the birds spend 68% of their time feeding, with peaks of activity during the early morning and late afternoon. a total of 21 641 ixodid ticks were found in 53 stomachs examined, with a range of between 16 and 1 665 per stomach. boophilus and rhipicephalus were the most important genera eaten. thirty diptera, also found in the stomachs, accounted for 0,4% of the diet by mass. the foo ...19807413164
susceptibility to cholinesterase-inhibiting acaricides of organochlorine-resistant and susceptible strains of amblyomma variegatum (acari: ixodidae) and in organochlorine-susceptible strain of a. lepidum. 19807420364
cattle ticks from the waterberg district of the transvaal.macroscopically visible ticks were collected from the hides of 28 cattle slaughtered in pairs during a period of 14 months in the waterberg district. in order of prevalence rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, amblyomma hebraeum, hyalomma marginatum rufipes, ixodes cavipalpus, hyalomma truncatum and boophilus decoloratus were recovered. immature stages of the three commonest species constituted a major portion of the population for varying periods during the months april ...19807452655
ectoparasites collected from bobwhite quail in the southeastern united states.twenty-one species of ectoparasites representing 19 genera were collected from 481 bobwhite quail (colinus virginianus) from nine areas in four southeastern states. sixteen species, amblyomma americanum, haemaphysalis chordeilis, haemaphysalis leporispalustris, eutrombicula alfreddugesi alfreddugesi, neoschoengastia americana, boydaia colini, pterolichus sp., colinophilus wilsoni, megninia sp., apionacarus wilsoni, colinoptes cubanensis, menacanthus pricei, colinicola numidiana, gonoides ortygis ...19807463603
success of tick feeding on calves immunized with amblyomma americanum (acari: ixodidae) extract. 19817265136
response of hypersensitized guinea pigs to the feeding of amblyomma americanum ticks.guinea pigs acquired resistance to the feeding of immature amblyomma americanum ticks after a single infestation. the initial larval and nymphal feedings resulted in cumulative mortalities of 27.2 and 28.9%, respectively. the second and third larval infestations yielded cumulative mortalities of 50.5 and 52.4%, compared to 18.9 and 24.4% cumulative mortality from controls. second and third nymphal feedings resulted in 75.7 and 73.4%, and ticks from controls exhibited 36.6 and 34.7% cumulative mo ...19817267146
some effects of 60co irradiation on cowdria ruminantium in its tick host amblyomma hebraeum koch (acarina: ixodidae).an attempt was made to attenuate cowdria ruminantium by irradiation of the nymphal stage of its tick host, amblyomma hebraeum. the irradiated nymphs were homogenized and serial dilutions of the resultant suspension were injected intravenously into heartwater-susceptible sheep. no attenuation could be demonstrated but the results indicate that progressively more micro-organisms will be destroyed the higher the irradiation dosage applied, and that dosages between 20 and 30 kilorad apparently prove ...19817279384
suitability of birds and mammals as hosts for immature stages of the lone star tick, amblyomma americanum (acari: ixodidae). 19817288841
cutaneous basophil responses and immune resistance of guinea pigs to ticks: passive transfer with peritoneal exudate cells or serum.resistance to infestation by larval amblyomma americanum or rhipicephalus sanguineus ticks was transferred to naive guinea pigs with peritoneal exudate cells (pec) or serum from donors immunized by prior infestation with homologous tick larvae. in the a. americanum system, pec transfer induced 87% tick rejection, which was similar to the level of resistance in actively sensitized hosts. in the r. sanguineus system, pec conferred resistance (39% rejection) that was weaker than in actively sensiti ...19817299125
an investigation into the toxic principle in eggs of the tick amblyomma hebraeum.a purification procedure involving iso-electric focusing by means of which a toxic principle may be obtained in a pure form from crude egg extracts of amblyomma hebraeum is described. the molecular mass of the toxin is approximately 10 000 according to sedimentation equilibrium sedimentation, sodium dodecyl sulphate (sds) gradient gel electrophoresis and calculations from the amino acid composition. non-competitive proteinase inhibitory activity was found to be associated with the toxin. histopa ...19817312303
human 'seed tick' infestation. amblyomma americanum larvae. 19817316562
resistance and cross-resistance of guinea pigs to dermacentor andersoni stiles, d. variabilis (say), amblyomma americanum (linnaeus), and ixodes scapularis say.the ability of guinea pigs to acquire resistance to dermacentor andersoni and amblyomma americanum was determined by repeatedly infesting separate sets of guinea pigs with tick larvae. resistance was measured in terms of reduced numbers successfully engorging and reduced weight of those ticks that engorged. an 83% reduction in numbers of larvae engorging and a 64.5% reduction in the weight of engorged larvae were seen between the first and second infestations with d. andersoni. guinea pigs exhib ...19817328454
neurons sensitive to 2,6-dichlorophenol on the tarsi of the tick amblyomma americanum (acari: ixodidae). 19817328604
[amblyomma astrion dönitz, 1909 (ixodidae), a new experimental vector of heartwater disease]. 19817342212
evidence for a d1 dopamine receptor in the salivary glands of amblyomma americanum (l.).adenylate cyclase from the salivary gland of the lone star tick, amblyomma americanum, is stimulated by several derivatives of phenylethylamine; dopamine, noradrenaline, adrenaline and isoproterenol. octopamine and iota-dopa had no effect on basal adenylate cyclase activity. dopamine had the highest potency and the lowest ka, 0.4 micron; followed by adrenaline and noradrenaline, 23 micron; and isoproterenol, 0.15mm. when either noradrenaline or adrenaline was added to dopamine, each at its maxim ...19817346526
quantitative studies on the proteins, free fatty acids and glycogen contents of eggs of amblyomma variegatum (fabr) and boophilus decoloratus (koch) (ticks, ixodoidea: ixodidae). 19817197866
mammalian wildlife diseases as hazards to man and livestock in an area of the llanos orientales of colombia.development of the llanos orientales of colombia, and access to underdeveloped areas in the llanos, may create disease hazards to man and domestic animals or introduce exotic pathogens, creating reservoirs of infection for domestic animals and acting as limiting factors on the native wild species. a survey of wild animals common to the llanos revealed a number of parasites indigenous to the area. a total total of 59 mammalian species, representing eight orders were examined. haematozoa were repr ...19816788961
observations on the transmission of theileria mutans in south africa.four isolates of theileria mutans obtained from geographically distant parts of south africa by subinoculation of infected blood were found to be readily transmitted by the bont tick amblyomma hebraeum. all attempts to transmit these isolates with rhipicephalus appendiculatus were unsuccessful. possible explanations for differences between these results and those reported by earlier workers in this country are discussed.19816792579
potentiation by spiperone and other butyrophenones of fluid secretion by isolated salivary glands of ixodid ticks.isolated salivary glands from the ixodid tick, amblyomma hebraeum koch are stimulated to secrete fluid when exposed to dopamine (da), the maximum response occurring at 10(-6) m. spiperone, and a number of other butyrophenone derivatives, although lacking intrinsic activity, are able to potentiate the secretion elicited by supramaximal concentrations of da; this potentiation by spiperone is evident at concentrations in the femtomolar range. tranylcypromine, a potent, competitive inhibitor of mono ...19816273183
antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern connecticut.blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (sfg) rickettsiae during 1978-1980 in southern connecticut. of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against rickettsia montana (n = 34), r rickettsii (n = 31), r rhipicephali (n = 19), or the unclassified 369-c rickettsia (n = 90). end points greater than or equal to 1:8,192 to r rickettsii and to r r ...19826803626
experimental transmission of cowdria ruminantium by the gulf coast tick amblyomma maculatum: danger of introducing heartwater and benign african theileriasis onto the american mainland.the tick amblyomma maculatum proved to be an experimental vector of cowdria ruminantium, the cause of heartwater of ruminants. transstadial transmission from larva to nymph and from larva through nymph to adult was successful; however, an experiment on transovarial transmission gave negative results. neither a americanum nor a cajennense transmitted the infection. there is a potential danger of the disease gaining access to the american mainland from the caribbean where it is known to occur and ...19826808870
causal agents of bovine theileriosis in southern pathogenic and 4 mild bovine theileria strains from southern africa, all transmitted by rhipicephalus appendiculatus, were compared amongst themselves as well as to bovine and buffalo strains of the t. parva complex from eastern and southern africa and to bovine strains of t. taurotragi from tanzania considered to be derived from eland antelope. criteria used were parasitological, clinical, serological and cross-immunity characters. the mild strains are similar to bovine t. taurotragi. serol ...19826812250
epidemiology and transmission of theileria sp of cattle in australia.theileria sp occurs in cattle in australia where boophilus microplus is not present. two species of ixodid ticks namely haemaphysalis longicornis and h. bancrofti have been implicated as natural vectors. experimental transmission was obtained with these two species but attempts to transmit the infection with b. microplus, ixodes holocyclus and amblyomma triguttatum were not successful. although calves born in the enzootic area may become infected before one-month-old most show evidence of infect ...19826818938
protein changes in the salivary glands of the female lone star tick, amblyomma americanum, during feeding. 19827077436
blood eosinophil and basophil responses in guinea pigs parasitized by amblyomma americanum ticks.guinea pigs sensitized to tick feeding by a previous infestation express immune resistance when challenged. this state is associated with large accumulations of eosinophils, and especially of basophils, at cutaneous sites of tick feeding. the present study shows that primary and secondary tick feeding stimulate blood eosinophilia and basophilia that reflect the infiltration of these cells in the skin. primary feeding of amblyomma americanum larvae resulted in a mean tick yield of 81%, mean tick ...19827081550
amblyomma ticks found on cattle in the northwest of argentina. preliminary report.the phytogeographical and seasonal distributions of three species of amblyomma ticks found on cattle are presented. the material studied was collected during a four-year survey in the northwest of argentina. amblyomma neumanni shows predilection for the chaqueno serrano district although it was also found in ecotones (phytogeographical transition zones) of the adjacent western chaqueno district and the province of las yungas. amblyomma cajennense was found in the western chaqueno and chaqueno se ...19827081892
ablation of immunity to amblyomma americanum by anti-basophil serum: cooperation between basophils and eosinophils in expression of immunity to ectoparasites (ticks) in guinea pigs.basophils infiltrate the skin and other tissues as part of t lymphocyte and/or antibody-mediated immune responses to certain protein antigens, viruses, tumors, and parasites. although basophils may comprise a significant fraction of leukocytes in these reactions, their precise role has been poorly understood. guinea pigs expressing acquired immunity to the tick amblyomma americanum develop basophil- and eosinophil-rich cutaneous inflammatory responses at tick feeding sites, and tick rejection is ...19827086142
relationship between ticks and zebu cattle in southern uganda.tick populations were observed on zebu (bos indicus) cattle over a period of 2 years at entebbe, uganda where the climate was thought to be highly favourable for the free-living stages of ticks. collections of all instars of ticks were made from the body surfaces of the cattle at intervals of between 1 and 5 weeks. the species recorded in order of decreasing abundance were rhipicephalus appendiculatus, amblyomma variegatum, boophilus decoloratus, rhipicephalus evertsi evertsi, rhipicephalus simu ...19827101465
[experimental transmission of the yellow fever virus by the tick amblyomma variegatum (f.) (author's transl)].experimental transmission of the yellow fever virus by the tick amblyomma variegatum (f.) (the tropical bont tick) is demonstrated for the first time. the tick transmitted the virus from one monkey to another. trans-stasial passage from nymph to adult stage was also demonstrated. the possible role of amblyomma variegatum as a vector and a potential reservoir of yellow fever is discussed.19827105284
growth in lone star ticks, amblyomma americanum (acari: ixodidae), feeding on cattle: a laboratory study. 19827120307
regulation of feeding and ovipositional success of amblyomma americanum ticks. 19827128750
immune serum transfer of cutaneous basophil-associated resistance to ticks: mediation by 7sigg1 antibodies.guinea pigs acquired resistance to amblyomma americanum larval ticks after one infestation, resulting in 46% tick rejection when challenged. intravenous transfer of immune serum from twice-infested hosts to naive animals conferred a significant level of immunity resulting in 18 to 30% tick rejection. the minimum effective dose of serum was 3 ml per recipient, and heating the serum at 56 degrees c for 4 hr had no effect on serum activity. fractionation of whole immune serum by gel filtration chro ...19827142697
heartwater (cowdria ruminantium infection) on são tomé.the supernatant obtained after centrifugation of an emulsion of engorged female amblyomma astrion ticks, collected from cattle on the west african island of são tomé, was injected intravenously into a goat, which contracted heartwater. this confirmation of the existence of the disease on the island makes strict control measures necessary if present efforts at improving livestock production by imported exotic cattle are to be successful.19827147672
antibody- and cell-mediated immune resistance by guinea pigs to adult amblyomma americanum ticks.naive and actively and passively sensitized guinea pigs were infested with adult amblyomma americanum ticks. naive hosts allowed for 75-81% tick yield, 518-581 mg mean tick weight and an average tick feeding period of 12-13 days. actively sensitized and challenged hosts, however, allowed only 47% tick yield (38.9% rejection), replete individuals were significantly reduced in weight (66.1% weight decrease) and required slightly longer time to feed (14 days). passively sensitized hosts were given ...19827149113
comparative ultrastructure of the spermatids and spermatozoa of the tick hyalomma dromedarii and amblyomma hebraeum (acari: ixodidae). 19827153570
parasites of domestic and wild animals in south africa. xv. the seasonal prevalence of ectoparasites on impala and cattle in the northern transvaal.the prevalence of ectoparasites on a total of 36 impala (aepyceros melampus) slaughtered monthly from february 1975 to february 1976 and a total of 24 cattle slaughtered monthly from march 1976 to march 1977 in the nylsvley provincial nature reserve was determined. six species of ixodid ticks were collected from the impala and these, in order of abundance, were: rhipicephalus evertsi evertsi, rhipicephalus appe. diculatus, amblyomma hebraeum, boophilus decoloratus, ixodes cavipalpus and hyalomma ...19827177586
a dopamine sensitive adenylate cyclase in the salivary glands of amblyomma americanum (l.).1. enzyme activity, basal or dopamine-stimulated (10 microm), was linear with time to 25 min and with protein concentration to 0.8 mg protein/ml of final assay volume. activity was maximal between ph 7.0 and 7.5. 2. mg2+ maximally stimulated basal or dopamine-sensitive adenylate cyclase activity at about 4 mm. 3. adenylate cyclase had a km of 0.042 mm for atp and maximum velocities for basal and dopamine-stimulated activity of 107 and 179 pmol cyclic amp formed/mg protein per min, respectively. ...19826125338
alveolar structure of salivary glands of the lone star tick, amblyomma americanum (l.): unfed females.alveoli in the salivary glands of unfed amblyomma americanum (l.) females (postnymphal ticks that had not yet taken a bloodmeal as an adult) were studied. as in other species of female ixodid ticks, the salivary glands consisted of three alveoli, one agranular and two granular. the agranular alveoli were directly attached to the anterior portion of the main salivary duct, consisted of approximately 13 to 14 cells, and were without valves. six peripheral cells had tortuous, plasma membrane infold ...19827200514
evidence for multiple receptors mediating fluid secretion in salivary glands of ticks.using isolated salivary glands of the ixodid tick amblyomma hebraeum koch, we tested the effectiveness of butaclamol and sulpiride in blocking fluid secretion stimulated by a number of agonists. (+)-butaclamol was a potent inhibitor of dopamine, n-methyldopamine and noradrenaline (ki congruent to 30-60 nm), but was less effective on ergometrine (ki congruent to 310 nm). tranylcypromine-stimulated fluid secretion in the absence and presence of (+)-butaclamol and (+/-)-sulpiride suggested that tra ...19836188618
metazoan parasites of the eastern cottontail rabbit in western kentucky.forty-five eastern cottontail rabbits (sylvilagus floridanus allen), collected over a 15 mo period from two areas of western kentucky, were examined for disease conditions, helminth and arthropod parasites. a single lymphosarcoma, two cutaneous papillomas and the following parasites were identified: hasstilesia tricolor, taenia pisiformis, cittotaenia variabilis, raillietina stilesiella, obeliscoides cuniculi, trichuris leporis, longistriata noviberiae, trichostrongylus calcaratus, dermatoxys ve ...19836842731
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