PMID(sorted ascending)
the ecology of the lone star tick, amblyomma americanum (l.), in two contrasting habitats in virginia (acarina: ixodidae). 19715153583
response of ovipositing amblyomma maculatum koch (acarina: ixodidae) to photoperiod. 19715160257
engorgement and reproduction of lone star ticks (amblyomma americanum (l.)) treated with gamma-radiation. 19665296972
ecology of tick vectors of american spotted fever.the author reviews the natural history of the tick vectors of american spotted fever. the discussion concerns the ecology of the rocky mountain wood tick, dermacentor andersoni, the american dog tick, dermacentor variabilis, and the lone-star tick, amblyomma americanum, all of which are proven vectors of rocky mountain spotted fever to man. also included are the rabbit tick, haemaphysalis leporispalustris and dermacentor parumapertus, which very rarely bite man but which are considered of import ...19695306621
[the tick amblyomma testudinis (conil 1877): its development and effect on the host]. 19695380272
a new species of amblyomma from iguanas in the caribbean (acarina: ixodidae). 19695391156
effect of age on the attachment rate of the parasitic stages of the lone star tick, amblyomma americanum (linnaeus) (acarina: ixodidae), in the laboratory. 19705435814
mating behavior and reproduction of the lone star tick, amblyomma americanum. 19705449398
amblyomma (acarina: ixodidae) on white-tailed deer, odocoileus virginianus (zimmermann), from south texas with implications for theileriasis. 19705501217
[contribution to a study of the ticks of senegal (acarina, ixodoidea). i. larvae of amblyomma (koch) and hyalomma (koch)]. 19705508156
fine structure of tarsal sensilla in the tick amblyomma americanum (l.). 19715541841
ticks in the south african zoological survey collection. 13. gynanders of boophilus decoloratus (koch, 1844) and amblyomma hebraeum koch, 1844. 19675586994
field vector studies of epizootic east coast fever. vi. the occurrence of amblyomma variegatum and a. lepidum in the east coast fever zones. 19685750916
eradication efforts against tropical bont tick, amblyomma variegatum, in the virgin islands. 19695766830
arbovirus studies in the ohio-mississippi basin, 1964-1967. vii. lone star virus, a hitherto unknown agent isolated from the tick amblyomma americanum (linn). 19695810802
white-tailed deer, a new host for amblyomma inornatum. 19695816091
[amblyomma chabaudi rageau, 1964. (ixodidae). description of the female and the nymph. morphologic variations of the male]. 19655864221
[isolation of toxoplasma gondii in naturally infected ixodidae of the genus amblyomma]. 19655892111
[isolation of a strain of rickettsia conori from larvae of amblyomma variegatum in guadeloupe]. 19666013770
[amblyomma chabaudi rageau, 1964 (ixodidae). breeding in the laboratory. description of the larva. complementary observations on the nymph]. 19676062855
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
adenosine-3',5'-monophosphate in salivary glands of unfed and feeding female lone star ticks, amblyomma americanum (l.).basal levels of camp in salivary glands of female lone star ticks were found to be about 5 pmoles/mg protein during all stages of feeding. glands stimulated with 10(-5)m dopamine and 10(-5)m dopamine plus theophylline exhibited significant increases in camp/mg protein. after stimulation by 10(-5)m dopamine was removed, camp decreased faster in glands from slowly feeding ticks (less than 200 mg) than in glands of rapidly feeding ticks (greater than 200 mg).19846149877
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
properties of na, k-atpase from the salivary glands of the ixodid tick amblyomma hebraeum. 19806253039
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
immunohistochemical localization of adenosine 3':5'-cyclic monophosphate in female ixodid tick amblyomma americanum (l.) salivary glands.localization of adenosine 3':5'-cyclic monophosphate (cyclic amp) in alveoli of salivary glands of female amblyomma americanum (l.) was accomplished with an indirect immunofluorescent technique. little cyclic amp fluorescence was seen in type i alveoli in glands of unfed females but considerable fluorescence was seen in type i alveoli of glands obtained from females that had fed. the most intense cyclic amp fluorescence was observed in complex granular cells of type ii and iii alveoli in glands ...19836298395
[recent advances in the study of the vector role of ticks of the genus amblyomma (ixodidae)]. 19836417741
isolation and transmission of theileria mutans (chisamba) in zambia.theileria mutans (chisamba) was isolated from a steer at chisamba, central province, zambia by inoculation of blood into a susceptible unsplenectomised calf. the parasite was then transmitted on three occasions by nymphs and once by adult amblyomma variegatum ticks. macroschizonts, typical for t mutans, were detected in two calves for short periods. the parasite caused varying degrees of anaemia in all experimental calves, whose sera showed high antibody titres to t mutans in the indirect fluore ...19846424195
theileria mutans infection in nigerian a 12 year survey in the former northern provinces of nigeria antibodies to theileria mutans were found to have a prevalence rate of 32.6 to 85%. the indirect fluorescent antibody test was found to be more efficient than thin blood smear examination in detecting cattle exposed to t. mutans. the high prevalence of t. mutans infection was attributed to the high prevalence of amblyomma species in the area under study.19846435298
characterization of tick antigens inducing host immune resistance. i. immunization of guinea pigs with amblyomma americanum-derived salivary gland extracts and identification of an important salivary gland protein antigen with guinea pig anti-tick antibodies.guinea pigs immunized by subcutaneous injection of an emulsion of incomplete freund's adjuvant (ifa) containing tick salivary gland extract antigens (sga) from partially fed female ticks expressed a significant level of tick rejection when challenged 17 days later. this level of tick rejection was similar to animals actively sensitized by tick feeding and challenged at the same time. sga emulsified with complete freund's adjuvant (cfa) or administered with saline was ineffective. however, ticks ...19846491289
studies on ticks of veterinary importance in nigeria xvii. resistance of rabbits to infestation with amblyomma variegatum and boophilus decoloratus (acari: ixodidae).rabbits exposed to larvae, nymphs and adults of amblyomma variegatum acquired resistance to the infestation with adults of this tick. the degree of acquired resistance was lowest in the rabbits exposed once previously to larvae and highest in those exposed twice previously to adults. rabbits also acquired resistance after primary infestation with boophilus decoloratus; their resistance became very high during the thrice-repeated feeding. new terms are introduced for the quantification of the deg ...19846510837
ticks on white-tailed deer fawns from southern illinois.seventy-six white-tailed deer (odocoileus virginianus (zimmermann] fawns captured on crab orchard national wildlife refuge in southern illinois during june-july 1980-1983 were aged and examined for ticks. the prevalence of ticks (amblyomma americanum (linnaeus, 1758) and dermacentor variabilis (say, 1821] was 80%; intensity of infestation ranged from one to 123 ticks per fawn, averaging 21.6. tick intensity correlated poorly with age suggesting that there were other, more important determinants ...19846530716
records of the bont tick, amblyomma hebraeum, from the angulate tortoise, chersina angulata, and the leopard tortoise, geochelone pardalis.a. hebraeum nymphae were found on 4 angulate tortoises and 13 leopard tortoises in the addo elephant national park, eastern cape province. adults of this species were collected for the 1st time from a leopard tortoise in the mkuze game reserve, natal. the significance of this finding, in relation to the normal host preferences of this tick, is briefly discussed.19846533508
[a new species of tick for madagascar, amblyomma loculosum, neumann 1907]. 19846534289
studies on ticks of veterinary importance in nigeria. xi. observations on the biology of ticks detached from the red-flanked duiker (cephamophys rufulatus) and parasites encountered in their blood.some aspects of the biology of amblyomma variegatum and boophilus decorolatus detached from red-flanked duikers were studied. smears were also made from the blood of the duikers and examined for the presence of parasites. anaplasma marginale was the only blood parasite found in the blood smears. compared with ticks detached from cattle, duiker ticks produced a greater number of eggs. the lengths and breadths of eggs produced by duiker ticks were greater than those of cattle ticks and unlike a. v ...19846538723
seasonal pattern of tick load in bunaji cattle in the subhumid zone of nigeria.the seasonal pattern of tick load on bunaji cattle under traditional management in northern nigeria was observed over 12 months to investigate the possibilities of strategic use of acaricide. ticks were removed 2-3 times weekly by hand from 16 animals, counted and the species determined. tick load was low in the dry season (2-5 ticks per animal per week), increased after the onset of the first scattered rains, reached a peak (40 ticks per animal per week) 1 month after the beginning of the heavy ...19846541842
bovine resistance to amblyomma americanum ticks: an acquired immune response characterized by cutaneous basophil infiltrates.purebred holstein calves acquired resistance to amblyomma americanum adult ticks after 1 infestation and expressed resistance during a challenge infestation 26 days later. tick yields from resistant animals were normal, but mean tick weight and egg-mass weight were reduced significantly (31 and 32%, respectively). cutaneous cellular responses at tick feeding sites in primary (naive) hosts consisted almost exclusively of mononuclear cells, until 24-h post-infestation when granulocytes appeared. a ...19846543047
copulation and successful insemination by unfed amblyomma triguttatum triguttatum koch. 19836631646
a bioassay technique for the pheromone emitted by amblyomma hebraeum males.attachment of amblyomma hebraeum females, either around feeding males or in areas in which extracts of fed males had previously been placed, was studied. the percentage attachment of female ticks around feeding males was significantly higher than that inside extract-treated areas. it was also found that the percentage attachment around the males increases with time, but there is little or no increase in attachment with time inside the treated areas. the amount of pheromone released by 1 feeding ...19836634086
some helminth and arthropod parasites of the grey duiker, sylvicapra grimmia.sixteen grey duikers were culled on the farm riekert 's laager in the central transvaal at irregular intervals from may 1979-march 1981. one trematode species, 3 cestode species and 16 nematode species were recovered from these animals. of these the following are new helminth records for this antelope: cooperia hungi , cooperia neitzi , cooperia pectinata , trichostrongylus axei, trichostrongylus colubriformis, trichostrongylus falculatus , trichostrongylus instabilis , impalaia tuberculata , ne ...19836676685
pheromone-induced aggregation of ixodid ticks before host contact.the presence of a pre-feeding aggregation pheromone was demonstrated in the species dermacentor variabilis, dermacentor andersoni, dermacentor parumapertus, amblyomma americanum and haemaphysalis leporispalustris by assay within a petri dish. however, amblyomma maculatum and amblyomma cajennense did not aggregate in the sector containing discs of presumed pheromone within the hour period. d. andersoni and a. americanum recognized each other's pheromone and a. americanum recognized that of h. lep ...19836683667
colonization and life cycle of amblyomma variegatum (acari: ixodidae) in the laboratory in puerto rico. 19846694178
effect of host age on the expression of acquired resistance to ticks.young guinea-pigs (350 g) expressed significantly greater levels of acquired resistance to challenge by larval amblyomma americanum ticks than older guinea-pigs (520-800 g). this finding suggests that younger guinea-pigs are immunologically more responsive to tick infestation than older mature individuals. therefore, host age is an important variable in evaluating acquired resistance to ticks.19846698176
amblyomma americanum: a potential vector of lyme disease in new jersey.amblyomma americanum is a likely secondary vector of lyme disease in new jersey. ticks of this species were removed from the site of the characteristic skin lesion known as erythema chronicum migrans on two patients with the disease, and the lyme disease spirochete was isolated from nymphs and adults of this species. that a. americanum is a potential vector is supported by its similarities to ixodes dammini, the known tick vector, in seasonal distribution and host utilization. the extensive rang ...19846710158
studies on ticks of veterinary importance in nigeria. viii. differences observed in the biology of ticks which fed on different domestic animal hosts.ticks of the species amblyomma variegatum (fabr.), boophilus decoloratus (koch), boophilus geigyi aeschl. et morel, and hyalomma rufipes koch were detached from cattle, sheep and horses and the influence of these various hosts on the biology of ticks was investigated. no a. variegatum was found in horses. the parameters studied were preoviposition and oviposition periods, ovipositional capacity, eclosion period, hatching patterns, egg sizes and temperature effect. although the preoviposition and ...19846714846
development of ixodid ticks under natural conditions in nigeria.the developmental periods of five tick species were recorded from egg to adult stages under natural conditions. the ticks were amblyomma variegatum, boophilus decoloratus, b. geigyi, hyalomma rufipes and h. truncatum and the natural condition was a grazing field on which "open" site and "shade" were recognised. the investigation took place between april 1980 and march 1981. the hatching patterns of larvae, attachment, engorgement, larvo-nymphal and nympho-adult moulting periods and the survival ...19846729999
susceptibility of ticks to acaricides in zambia.the susceptibility of some zambian ticks to dieldrin, dioxathion, dimethoate and chlorfenvinphos was determined on two- to three-week-old larvae of amblyomma variegatum, boophilus decoloratus, b. microplus, rhipicephalus appendiculatus, r. e. evertsi and a member of the r. pravus group. some strains of b. decoloratus and r. appendiculatus were resistant to dieldrin, dioxathion and dimethoate and some r. e. evertsi were resistant to dieldrin and dioxathion. a single strain of an r. pravus group t ...19846730000
ixodid ticks on feral swine in florida.more than 99% of the 645 feral swine (sus scrofa l.) in southern florida harbored ixodid ticks. dermacentor variabilis (american dog tick) was present on 99.6% of the swine and comprised 82.5% of the ticks collected. amblyomma maculatum (gulf coast tick) occurred on 85.9% of the hosts and 17.4% of the collections were of this species. amblyomma americanum (lone star tick) and ixodes scapularis (black-legged tick) were found infrequently and together constituted less than 0.1% of the ticks. pigs ...19846737605
isolation and transmission of cowdria ruminantium (causal agent of heartwater disease) in blue nile province, sudan.heartwater was diagnosed in sheep at the umm banein livestock research station, blue nile province, sudan. cowdria ruminantium was isolated from sheep by subinoculation of blood into a goat. adult amblyomma lepidum ticks fed as nymphs on this goat transmitted heartwater to a friesian (bos taurus) calf. brain stabilates from this calf, either snap-frozen into liquid nitrogen or frozen slowly in a deepfreezer at -70 degrees c, with dmso as cryoprotectant, were infective to cattle when inoculated s ...19846740919
[seasonal dynamics in the development of boophilus microplus and amblyomma cajennense in camagüey, cuba].studies were carried out on the occurrence of the ixodic ticks in farm animals in the province of camagüey, cuba. most spread proved to be the boophilus microplus and amblyomma cajennense species. as many as three waves of parasitic activity were seen with b. microplus: at the end of the winter season, in the months of may and june, and in the autumn (october and november). only one wave was there with the activity of a. cajennense, covering the period of march-september.19846740935
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
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
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
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
tick paralysis in brazil.from july to december 1977 and from june to november 1978 the toxic effects of amblyomma cajennense were studied in cattle sheep and goats. locomotor disturbances commencing as hind-limb paralysis ascended to the upper nervous centres causing paralysis. this was observed in natural infections and confirmed experimentally. tick paralysis is reported for the first time in brazil, manifesting itself in a different form to that usually attributed clinically to the disease. also for the first time re ...19836868132
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
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
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
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
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
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
bacteriocidal qualities of ixodid tick (acarina: ixodidae) salivary cement plugs and their changes under the influence of a viral tick-borne pathogen.the abundance of bacteriocidal compounds contained in the salivary cement plug of ixodid ticks was changed because of the reproduction of tick-borne encephalitis virus (tbev) in their bodies. the size of tbev-infected ixodes persulcatus shulze lytic zone surrounding the cement plug enlarged to that of naive ticks, whereas micrococcus lysodeikticus (cohn) lytic zones induced by the cement plugs of tbev-infected amblyomma hebraeum koch nymphs or rhipicephalus appendiculatus neumann females were re ...19957473610
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