TitleAbstractYear(sorted ascending)
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
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
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
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
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
pheromones and other semiochemicals of the contrast to the exceptional diversity of semiochemical-regulated behavior in the insects, chemical communication in the acari is restricted to a few limited roles. these include clustering, mate-finding processes, host- and food-finding processes, and dispersal. no evidence of pheromones regulating oviposition, necrophoric behavior, recognition of hive mates, or many other processes found in numerous insect groups has been reported in the acari. perhaps the most noteworthy feature of acarine ...19852857547
prevalence of ectoparasites of small ruminants in nsukka, nigeria.over a period of one year (january 1983 to december 1983), an investigation was mounted to determine common ectoparasitic infestation of small ruminants in selected farms in nsukka, nigeria. the species identified in goats included ctenocephalides canis, boophilius decolouratus and amblyomma variegatum lides while those recovered from parasitized sheep were ctenocephalides canis and damalinia ovis. out of a total of 148 sheep and goats examined for ectoparasites, 68 (45.95%) were infested. a fur ...19853836218
efficacy of ivermectin against ectoparasites of cattle in south africa.the efficacy of various formulations of ivermectin administered at the recommended dose rate of 200 micrograms/kg was evaluated in cattle infested with mange mites (sarcoptes scabiei var. bovis.), lice (linognathus vituli and damalinia bovis) and ticks (boophilus decoloratus, amblyomma hebraeum, rhipicephalus appendiculatus and hyalomma spp.) in 8 trials conducted in south africa. mange mites (s. scabiei) were eliminated from animals treated subcutaneously, resulting in marked clinical recovery. ...19853839021
observations on the efficacy of ivermectin in the control of cattle ticks in zambia.the efficacy of multiple subcutaneous injections (200 micrograms/kg) of ivermectin in the control of naturally occurring tick infestations on traditionally managed tonga-iia (sanga type) calves and yearlings was assessed in two field trials. in the first trial boophilus decoloratus infestations were decreased following treatments at monthly intervals. in the second trial, with weekly and two weekly treatment intervals, infestations of rhipicephalus appendiculatus were controlled less effectively ...19853841240
[preliminary note on the sensitivity of amblyomma variegatum and boophilus decoloratus (acarida, ixodidae) to organophosphate acaricides in the people's republic of the congo]. 19853841963
studies on ticks of veterinary importance in nigeria. xii. oviposition and eclosion in five species of ixodid ticks in contrasting habitats.the preoviposition and oviposition periods, the eclosion periods and numbers of eggs laid by adult ticks of five species, namely amblyomma variegatum, boophilus decoloratus, b. geigyi, hyalomma rufipes and h. truncatum, maintained in a natural habitat were compared with those maintained in semi-natural and artificial habitats. within the natural habitats, "open" and "shady" sites were distinguished. maximum oviposition occurred during the peak of the rains in engorged a. variegatum and b. decolo ...19853870956
systemic activity of closantel for control of lone star ticks, amblyomma americanum (l.), on cattle.cattle were treated once at 5 mg/kg orally or subcutaneously or daily at 0.1-5 mg/kg orally or 0.1-1 mg/kg subcutaneously with closantel, n-[5-chloro-4-[(4-chlorophenyl)cyanomethyl]-2-methylphenyl]-2-hydroxy-3, 5-diiodobenzamide, and numbers and weights of engorged females, weights of egg masses and hatch of eggs of lone star ticks, amblyomma americanum, were recorded. effectiveness of treatments on reproduction was determined by comparing total estimated larvae (el) (el = wt. egg mass x est. % ...19853870959
a method for determining the cowdria ruminantium infection rate of amblyomma hebraeum: effects in mice injected with tick homogenates.amblyomma hebraeum ticks, collected in the field and individually homogenized, were injected into mice. thirteen out of 240 ticks were shown to be infected with the heartwater agent. antibodies against cowdria ruminantium were detected in the sera of the mice by means of the indirect fluorescent antibody test. giemsa-stained smears, prepared from the haemocytes of the ticks, revealed morphologically different forms of the heartwater agent. a strain of c. ruminantium, designated the welgevonden s ...19853900855
rickettsia-like organisms in ticks and antibodies to spotted fever-group rickettsiae in mammals from northern mississippi.studies were conducted from april through august during 1974 and 1975 on 30 randomly selected trapping sites in wall doxey state park, holly springs national forest, and 1.6 km south of the park in marshall county, mississippi to provide information on the occurrence of ticks involved in the maintenance and transmission of spotted fever-group rickettsiae in nature. of 365 animals (14 species) collected, 186 (51%) were parasitized by 4,169 ticks. species of ticks collected included: dermacentor v ...19853923212
amblyomma americanum: requirement for host fc receptors in antibody-mediated acquired immune resistance to ticks.guinea pig recipients of anti-tick immune serum or immune peritoneal exudate cells expressed 25 and 30% tick rejection, respectively, when challenged with amblyomma americanum larval ticks. previous studies have shown that igg1 antibodies are responsible for the ability of immune serum to transfer resistance to ticks and to mediate the accompanying, and required, cutaneous basophil response. since igg1 antibodies induce mast cell-mediated passive cutaneous anaphylaxis and cutaneous basophil resp ...19853972060
cytogenetics of ticks (acari: ixodoidea): chromosomes and timing of spermatogenesis in amblyomma inornatum. 19853981339
surveillance of lyme disease in the united states, 1982.lyme disease is a tick-borne illness that has been reported from three regions in the united states--the northeast, midwest, and west--which correspond to the distribution of the recognized vectors of the disease, ixodes dammini and ixodes pacificus. in 1982, a surveillance system designed to define the morbidity and geographic distribution for lyme disease by using a clinical case definition received information on 491 definite cases and 38 probable cases. of the definite cases, 489 were acquir ...19853998509
acquisition and expression of resistance by bos indicus and bos indicus x bos taurus calves to amblyomma americanum infestation.purebred and crossbred bos indicus calves were infested 1, 2, or 3 times with 10 female and 5 male amblyomma americanum. resistance was acquired by both the purebred and the crossbred calves after 1 infestation and resulted in statistically significant decreases in the percentages of females that engorged, the mean weights of engorged females, and the mean weights of egg masses. comparisons between breeds of the percent of female ticks that engorged during the first and second infestations indic ...19853998956
evaluation of five popular methods for tick removal.five methods commonly advocated for tick removal from a human or domestic animal were evaluated. the application of petroleum jelly, fingernail polish, 70% isopropyl alcohol, or a hot kitchen match failed to induce detachment of adult american dog ticks (dermacentor variabilis say) attached for either 12 to 15 hours or three to four days. use of forceps or protected fingers enabled satisfactory removal of 29 adult american dog ticks without leaving the mouthparts or attachment cement in the host ...19854000801
human infestation by amblyomma americanum larvae ("seed ticks"). 19854002011
systemic activity of a benzimidazoline compound in cattle against ticks and biting flies.a benzimidazoline compound [4-nitro-2-(1,1,2,2-tetrafluoroethyl)-6 -(trifluoromethyl)-1h-benzimidazol-2-, 01, sodium salt] referred to as el-979 showed systemic acaricidal and insecticidal activity in cattle against 2 tick species, amblyomma maculatum (gulf coast tick) and dermacentor variabilis (american dog tick) and adult stomoxys calcitrans (stable flies). larvae of black blow fly (phormia regina) were fed serum collected from treated calves. a complete kill of larvae was obtained with a ser ...19854002603
density estimators for populations of the lone star tick, amblyomma americanum (acari: ixodidae), on pastured beef cattle. 19854009621
[ecology of tick-borne arboviruses in the central african republic].ticks have been collected on cattle skins for seven consecutive years in bangui, berberati, bangassou and bouar. 150 strains of arboviruses have been isolated from the four following species: amblyomma variegatum: dugbe, jos, thogoto, crimean-congo hemorragic fever (cchf), yellow fever, bhanja and pétévo; boophilus annulatus: dugbe, jos and thogoto; b. decoloratus: dugbe, jos, thogoto and cchf; hyalomma nitidum: cchf. dugbe (112 isolated strains), jos (19 isolates) and thogoto (11 isolates) viru ...19854028317
cytogenetics of ticks (acari: ixodoidea). 18. chromosomes and laboratory biology of amblyomma dissimile. 19854045940
injury thresholds and production loss functions for the lone star tick, amblyomma americanum (acari: ixodidae), on pastured, preweaner beef cattle, bos taurus. 19854056195
resistance to ixodid tick infestation induced by administration of tick-tissue culture cells.primary tissue culture cells of developing larvae of amblyomma americanum were administered to guinea-pigs never previously exposed to ixodid ticks. guinea-pigs were given 1 x 10(6) primary culture cells on days 0, 7 and 21 by subcutaneous injection and challenged with male and female a. americanum on day 35. a significant degree of induced host tick resistance was expressed by reduced engorgement weight of females, reduced oviposition by those females which did obtain a blood meal, and by death ...19854083961
ticks on livestock in st. lucia.cattle, sheep, goats and horses were examined for ticks. over 95% of holstein cross-breeds, 28% of sheep (local mixed breeds) and 18% of goats (local mixed breeds) examined from 18 august to 4 september 1983 were infested with the southern cattle tick, boophilus microplus canestrini. about 90 and 17% of the horses examined were infested with the tropical horse tick, anocentor nitens neumann, and the tropical bont tick, amblyomma variegatum fabricius, respectively. the tropical bont tick was foun ...19854090245
weight changes in individual feeding amblyomma americanum female ticks. 19854093818
rejection of ticks from guinea pigs by anti-hapten-antibody-mediated degranulation of basophils at cutaneous basophil hypersensitivity sites: role of mediators other than histamine.previous studies have established that recruitment of basophils to sites of tick feeding in guinea pigs is required to effect immune resistance. in the current study, actively sensitized guinea pigs treated three times daily with h-1 (mepyramine) and h-2 (cimetidine) histamine receptor antagonists, during the challenge tick infestation period, expressed normal resistance to amblyomma americanum larvae. similarly, naive guinea pigs treated with anti-histamines four times daily, beginning 7 days b ...19852578152
epidemiology of theileriosis in calves in an endemic area of kenya.thirty-one calves born into five maasai zebu cattle herds over a period of 1 month in the trans-mara division of kenya, endemic for theileriosis, were recruited for an intensive study of theileriosis. no calves up to 6 months of age died but all developed theileria infections as judged by slide examination and serology. parasitosis by t. mutans schizonts in lymph node smears was usually higher than that of t. parva. the t. mutans schizonts usually occurred at an earlier age but persisted at a pa ...19863085323
density perturbation in populations of amblyomma americanum (acari: ixodidae) in beef cattle forage areas in response to two regimens of vegetation management. 19863950182
production system-based model for defining economic thresholds in preweaner beef cattle, bos taurus, infested with the lone star tick, amblyomma americanum (acari: ixodidae). 19863950186
intradermal infestation of a red fox (vulpes vulpes) by the lone star tick (amblyomma americanum). 19863951048
proof of transovarial transmission of cowdria ruminantium by amblyomma herbraeum.transovarial transmission of cowdria ruminantium by amblyomma hebraeum does occur in certain instances. both the transovarial and the filial infection rates appear to be very low. the infection may reappear only in the adults or nymphae, or in all 3 stages of the tick's life cycle.19863960489
the detection of antibodies to cowdria ruminantium in serum and c. ruminantium antigen in amblyomma hebraeum by an enzyme-linked immunosorbent assay.a sensitive and reliable enzyme-linked immunosorbent assay for the detection of antibodies to cowdria ruminantium in serum and c. ruminantium antigen in amblyomma hebraeum nymphae is described. for the screening of antibodies, c. ruminantium from a. hebraeum nymphae, partially purified by wheat-germ lectin affinity chromatography, was used as antigen. to screen nymph populations, sera from either ball 3 strain-infected sheep or kumm-strain infected mice were used. by using appropriate controls t ...19863960490
amblyomma americanum: physiochemical isolation of a protein derived from the tick salivary gland that is capable of inducing immune resistance in guinea pigs.crude salivary gland derived proteins from amblyomma americanum ticks were analyzed by physiochemical (gel filtration and ion exchange chromatography) and immunochemical guinea pig igg1 (anti-tick immunoaffinity column) techniques for the presence of antigens responsible for the induction of host immune resistance responses. gel filtration (g-75 sephadex) and ion exchange (diethyl aminoethyl cellulose) chromatography of crude salivary gland antigen yielded multiple fractions, but only one fracti ...19863720900
parasites of domestic and wild animals in south africa. xviii. the crowned guinea fowl (numida meleagris), an important host of immature ixodid ticks.the tick burdens of 10 crowned guinea fowl (numida meleagris), shot at approximately 3-monthly intervals in the mountain zebra national park, and of 21 crowned guinea fowl from the andries vosloo kudu reserve, the majority of which were shot at monthly intervals, were determined. no adult ticks were recovered from any of the guinea fowl. the birds in the mountain zebra national park harboured 4 species of ixodid ticks of which amblyomma marmoreum was the most abundant and most prevalent. three b ...19863725331
[isolation of a new orbivirus kindia (palyam group) from ticks amblyomma variegatum in the republic of guinea].a new arbovirus named "kindia" has been isolated from ticks amblyomma variegatum in guinea (west africa), district kindia. this virus is classified into palyam group of orbiviruses, due to its physico-chemical, biological and antigenic properties.19863731365
serum basophil-stimulating activity in the guinea-pig during induction of basophilic responses to ovalbumin and tick feeding.we have described functional and biochemical characteristics of a distinct t-cell dependent guinea-pig basophil-stimulating factor (bsf), measured using a sensitive 7-day bone marrow culture assay, standardized with high-activity bsf present in serum-free splenic cell-conditioned medium (cm). in the present studies, the in vivo relevance of bsf was explored during protocols of induction of peripheral blood or tissue basophil responses to ovalbumin (oa) injection or amblyomma americanum tick feed ...19863733145
physiological and biochemical changes in unfed lone star ticks, amblyomma americanum (acari: ixodidae), with increasing age. 19863735326
the effect of photoperiod on the development of amblyomma triguttatum triguttatum (acari: ixodidae). 19863735330
electrophoretically detectable protein variation in natural populations of the lone star tick, amblyomma americanum (acari: ixodidae).nine populations of amblyomma americanum (l.) were examined electrophoretically for variation of 21 enzymes. only three enzymes were not polymorphic and the average heterozygosity per individual (h) for the species was 0.085 with a range of 0.077 to 0.110, comparing well with values in other arthropods. the average nei identity value for pairwise comparisons among the nine populations was high, 0.994 +/- 0.004 (i +/- sd). these high identity values and the absence of geographic structuring of th ...19863744877
differentiation between three species of amblyomma ticks (acari: ixodidae) by analysis of cuticular hydrocarbons.cuticular lipids were extracted from three species of amblyomma ticks in hexane: dichloromethane and analysed by gas-liquid chromatography using both packed and capillary columns. unlike many of the reported insect hydrocarbons, those of the amblyomma ticks consisted mostly of branched paraffins and olefins and all three species of ticks are well differentiated on the basis of numbers and carbon-chain lengths of the hydrocarbons. amblyomma maculatum has more olefins and a. cajennense has more pa ...19863753063
metabolism of [3h]ecdysone by isolated tissues of the female ixodid tick amblyomma hebraeum (ixodoidea; ixodidae).malpighian tubules, gut, ovaries and carcasses of the adult female tick amblyomma hebraeum were incubated in vitro in the presence of 2 microm [3h]ecdysone. organs and media were separately extracted after 6, 24 and 48 h incubations and the patterns of ecdysone metabolites were analyzed by hplc. esterase-susceptible apolar metabolites similar to the ap2 already described in the soft tick ornithodoros moubata and thus presumably corresponding to the same conjugates (c-22 esters with fatty acids) ...19863758475
spotted fever group rickettsiae in the lone star tick, amblyomma americanum (acari: ixodidae). 19863772952
ectoparasitic fauna of poultry in nsukka, investigation which lasted for a period of one calendar year was mounted to determine common ectoparasitic fauna of poultry in nsukka, nigeria. this survey covered twenty commercial poultry farms located in different areas of nsukka. birds were picked and thoroughly examined visually for the presence of ectoparasites after horizontal displacement of the feathers against their anatomical direction of alignment. identification was mainly by morphological characteristics, host preference and ana ...19863793395
amblyomma arianae, n. sp. (acari: ixodidae), a parasite of alsophis portoricensis (reptilia: colubridae) in puerto rico. 19863795233
a study of the justification for intensive tick control in kenyan rangelands.sixty male weaner cattle at the national range research station, kiboko, kenya were placed in four groups of 15 animals under four different tick control regimens for 16 months. the treatment groups were: spraying with acaricide weekly, spraying every three weeks, spraying whenever group mean tick infestations reached more than 200 per animal (once only in the course of the study) and a control unsprayed group. the cattle were weighed monthly. there were no significant differences between the li ...19863798681
isolation of cowdria ruminantium by means of percoll density gradient centrifugation and detection by an enzyme-linked immunosorbent assay.the isolation of cowdria ruminantium by means of percoll density gradient centrifugation permits the recovery of partially purified viable populations of the organism possessing distinctly different densities. these conclusions are based upon results of analyses of density fractions by intravenous inoculation into sheep, protein determination, electron microscopy and enzyme-linked immunosorbent assay. morphological differences were observed in the density fractions obtained from infected brain t ...19863014417
the effect of avermectins on feeding, salivary fluid secretion, and fecundity in some ixodid ticks.we tested the effects of the potent acaricides, avermectin b1a (avm) and 22,23-dihydroavermectin b1 (ivermectin; ivm) when injected directly into partially fed and fully engorged female ticks. when injected into small ticks (amblyomma hebraeum koch), neither drug (up to 100 micrograms/kg b.w.) inhibited subsequent engorgement nor affected oviposition latency, weight of total egg mass laid nor viability of laid eggs. at higher concentrations (1000 and 5000 micrograms/kg b.w.), avm and ivm were ma ...19863451859
ecology and phenology of ticks in zambia: seasonal dynamics on cattle.a study of the seasonality and infestation rates of ticks was carried out in 11 cattle herds in different ecological habitats in zambia between 1980 and 1982. wherever possible supplementary data were obtained from opportunistic collections from cattle and other hosts. analysis of over 1000 tick collections from cattle indicated that infestation rates of the most important species, amblyomma variegatum and rhipicephalus appendiculatus vary in different ecological habitats: (i) in western provinc ...19863451861
field tests of the response of female amblyomma variegatum (acari:ixodidae) to the synthetic aggregation-attachment pheromone and its components.fifty percent of an amblyomma variegatum female population were able to find upwind-positioned targets containing the synthetic aggregation-attachment pheromone of this species or the pheromone component o-nitrophenol alone. the ticks were not attracted to the other components of the pheromone: methyl-salicylate and pelargonic acid. the mean time required for the ticks to reach a target at 1 m from the starting point was 3 min and 20 s.19863451866
a comparison of the tick burdens of wild animals in a nature reserve and on an adjacent farm where tick control is practised.acaricidal treatment of cattle, sheep and goats on a farm in valley bushveld in the grahamstown district resulted in a reduction in the numbers of certain tick species on kudu (tragelaphus strepsiceros), scrub hares (lepus saxatilis) and crowned guinea fowl (numida meleagris) on the same farm. the tick species most severely affected was amblyomma hebraeum, while haemaphysalis silacea, hyalomma marginatum rufipes and rhipicephalus appendiculatus were affected to a lesser extent. rhipicephalus gla ...19863572954
comparison of rates of infection by the lyme disease spirochete in selected populations of ixodes dammini and amblyomma americanum (acari: ixodidae).at a major endemic focus in new jersey, 50% of 290 adult ixodes dammini collected in the fall of 1984 were infected with the lyme disease spirochete (borrelia burgdorferi), which was statistically higher than the rate found in the 202 adult ticks (39.6%) examined during the spring. neither sex nor site of collection within the focus significantly affected the infection rate. the observed infection rates were similar to those reported in endemic areas of new york and connecticut. borrelia burgdor ...19863577494
theileria orientalis occurs in central outbreak of bovine theileriosis in burundi was investigated and the occurrence of theileria orientalis in central africa was confirmed for the first time. its identity was established on morphological and serological grounds. the parasite was associated with clinical signs and further complicates the disease picture of bovine theileriosis in africa. amblyomma variegatum is suspected as being the local vector.19863517994
spirochetes in ticks and antibodies to borrelia burgdorferi in white-tailed deer from connecticut, new york state, and north carolina.ticks were screened for spirochetes and serum samples from white-tailed deer (odocoileus virginianus) were assayed for antibodies to borrelia burgdorferi during 1983-1984. using fluorescein isothiocyanate-labeled rabbit antibodies produced to b. burgdorferi, the etiologic agent of lyme disease, spirochetes were detected in ixodes dammini (10.5% of 1,193) and dermacentor albipictus (0.6% of 157) adults from connecticut, i. dammini nymphs (49.1% of 108) and adults (64.7% of 99) from armonk, new yo ...19863520030
amblyomma variegatum and acute bovine dermatophilosus. 198615462727
demonstration of colonies of cowdria ruminantium in midgut epithelial cells of amblyomma variegatum.the development of colonies of cowdria ruminantium was studied in midgut epithelial cells of adult amblyomma variegatum that had become infected by feeding as nymphs on cattle with experimentally induced heart-water disease. colonies were not observed in gut tissues obtained from nymphs during the feeding period, but were present in midgut epithelial cells of ticks obtained at 15 days after they were replete through molting to the adult stage. colonies were small (1 to 10 micron) initially, but ...19873551699
a seed tick infestation of the conjunctiva: amblyomma americanum larva.ticks commonly infest humans but rarely bite the eyes. they are vectors of disease; therefore, rapid and complete removal is important. their attachment can be so secure that removal is difficult or hazardous. we excised a larval form of amblyomma americanum from a woodsman's conjunctiva.19873566026
effects of gamma radiation on spermatogenesis and fertility of male amblyomma americanum (acari: ixodidae).amblyomma americanum males were treated with 0.5, 1, 2, 3, 4, 8, and 16 krad of gamma radiation. testes of ticks treated with 2, 3, 4, 8, and 16 krad were smaller than those of ticks irradiated at lower levels and controls. no recognizable alteration in timing of spermatogenesis was noted among the different radiation groups, but severe breakdown and depletion of germinal cells was noted at 4, 8, and 16 krad. percent hatch of larvae from crosses of irradiated males and untreated females decrease ...19873585625
computer simulation of population dynamics of the lone star tick, amblyomma americanum (acari: ixodidae). 19873585931
effects of season and area on ectoparasites of white-tailed deer (odocoileus virginianus) in mississippi.nine species of ectoparasites (4 acari, 2 mallophaga, 1 anoplura, 1 diptera, and 1 siphonaptera) were recovered from 126 white-tailed deer collected in northern, central, and southern mississippi. intensity and prevalence of adults of ixodes scapularis and larvae, nymphs, and adults of amblyomma americanum varied significantly over collection periods, but not between host sexes. lipoptena mazamae occurred on deer from only one study area. although individual deer were heavily parasitized by tric ...19873586204
ultrastructural features of cowdria ruminantium in midgut epithelial cells and salivary glands of nymphal amblyomma hebraeum.colonies of cowdria ruminantium were studied in midgut epithelial cells and salivary gland acini of nymphal amblyomma hebraeum that were infected experimentally as larvae. colonies were found in both tissues and studied with light and electron microscopy. colonies observed within gut cells frequently contained 2 types of the organism: electron-dense and reticulated forms. the morphology of colonies from salivary glands, as seen with light microscopy, varied from compact, densely-staining, small ...19873587934
the development of amblyomma americanum and dermacentor variabilis (acari: ixodidae) fed on rabbits immunized with tick hemolymph.the possibility of interfering with the normal function of tick hemolymph using antihemolymph antibodies taken in with the bloodmeal, was investigated. cell free hemolymph from replete amblyomma americanum and dermacentor variabilis ticks was used to immunize rabbits. immunized rabbits developed high antihemolymph antibody titers (ca. 10(5)) and had no ill side effects. rabbits were simultaneously infested with larvae, nymphs, and adult ticks. the biological performance of ticks fed on immunized ...19873588587
tick infestations on livestock in the yemen arab republic and their potential as vectors of livestock diseases.a survey of ticks on cattle, camels, sheep, goats and donkeys in four different geographical locations of the yemen arab republic (yar) was carried out to provide more information on the possible risk of tick-borne diseases to imported exotic cattle included in the yar's plans for livestock development. the most abundant ticks were hyalomma spp. particularly on camels. ticks found on cattle included hyalomma spp., amblyomma variegatum, boophilus annulatus and rhipicephalus spp. in general with t ...19873603710
protection of cattle against heartwater in botswana: comparative efficacy of different methods against natural and blood-derived challenges.five groups of tswana-cross castrated male cattle between 20 and 30 months of age (a total of 158 animals) were transported from a ranch in a heartwater-free area of south botswana to a feedlot near gaborone in the east of botswana where heartwater is endemic. on arrival, one group was vaccinated intravenously with the onderstepoort sheep blood heartwater vaccine, one group was vaccinated intravenously with the new onderstepoort tick-derived heartwater vaccine and a third group was vaccinated su ...19873604029
computer simulation of area-wide management strategies for the lone star tick, amblyomma americanum (acari: ixodidae). 19873669024
metabolism of ecdysteroids in the female tick amblyomma hebraeum (ixodoidea, ixodidae): accumulation of free ecdysone and 20-hydroxyecdysone in the eggs.[3h]-20-hydroxyecdysone ([3h]-20e) injected into amblyomma hebraeum females 7 days before the beginning of oviposition, viz. at the beginning of vitellogenesis, was converted to 3 polar peaks of unknown nature called 1, 2 and 3, and to apolar conjugates ap1, ap2 and ap3. ap2 have the same retention times as the esters of 20e with long chain fatty acids described in ornithodoros moubata (diehl et al. 1985). however, principally unmetabolized 20e was incorporated into the ovaries, and 16% of the i ...19873693624
a comparison of live and destructive sampling methods of determining the size of a parasitic tick populations.the accuracy of a general and a specific method of collecting and counting ixodid ticks on live hosts was compared with that of a destructive technique which can only be applied to dead animals. destructive sampling provided considerably more accurate results than either of the live sampling methods when applied to domestic goats (capra hircus) and a duiker (sylvicapra grimmia). the smaller the life stage and the tick species the less likely it is that it will be recovered by either of the live ...19873453335
[trial of flumethrine for amblyomma variegatum tick control on a cattle ranch in guadeloupe]. 19873453502
[oviposition and longevity of amblyomma variegatum fabricius, 1794 (ixodoidea : ixodidae) ticks in the people's republic of the congo]. 19873453516
foot abscess in goats in relation to the seasonal abundance of adult amblyomma hebraeum and adult rhipicephalus glabroscutatum (acari: ixodidae).the seasonal prevalence of foot abscess affecting angora and boer goats in valley bushveld in the eastern cape province of south africa was significantly related to the seasonal abundance of adult amblyomma hebraeum and adult rhipicephalus glabroscutatum. angora goats harboured more ticks than boer goats and also had a greater number of abscessed feet. larger numbers of ticks and abscesses were recorded on hind feet than on fore feet. there was no significant correlation between rainfall and the ...19873508202
distinctive staining of colonies of cowdria ruminantium in midguts of amblyomma hebraeum.mallory's phloxine-methylene blue stain was used to differentiate colonies of cowdria ruminantium in midgut epithelial cells of nymphal amblyomma hebraeum that had been infected as larvae. gut tissues were collected from nymphs that had fed on a susceptible sheep and were fixed in formol-saline on the day of repletion. paraffin sections, 3-4 micron thick, were then stained and this rendered colonies and cell nuclei densely blue against a uniformly pink background of tick tissues. colonies were e ...19872452397
morphology and development of cowdria ruminantium in amblyomma ticks.the morphology and development of cowdria ruminantium have been studied in amblyomma hebraeum and a. variegatum. colonies of c. ruminantium have so far been demonstrated microscopically in gut, salivary gland cells, haemocytes and malphighian tubules of infected amblyomma ticks. colonies in gut cells were seen in both unfed and feeding ticks but colonies in salivary gland acini were observed only in nymphs that had fed for 4 days. although the predominant type seen in both tick stages was the re ...19873448559
cowdria ruminantium: stability and preservation of the organism.blood collected in either sodium heparin or disodium edetate vacutainers from febrile goats infected with 4 isolates of cowdria ruminantium and cryopreserved with 10% dimethyl sulphoxide at -70 degrees c and -196 degrees c was an effective stabilate to initiate heartwater infections in goats. a homogenized pool of whole amblyomma variegatum ticks in snyder's buffer, maintained at -196 degrees c, was used to infect a goat with c. ruminantium. liver and spleen collected from swiss mice infected wi ...19873448560
epidemiology of heartwater in guadeloupe and in the present, heartwater in the caribbean is known with certainty only on guadeloupe, marie galante and antigua; the first 2 islands are widely infected. the most important factors responsible for particular aspects of heartwater in guadeloupe are: cowdria ruminantium of high virulence. a very resistant cattle population (creole), not normally clinically affected. a fairly susceptible goat population (creole) (22% goats born in endemic areas die after experimental inoculation) which, fortunately, ...19873448572
problems with the interpretation of epidemiological data in heartwater: a study on 23 an epidemiological study undertaken on 23 farms where heartwater occurs endemically, it was found that on an overall average, antibodies to cowdria ruminantium were detected in 64.3% of the cattle, 6 adult amblyomma hebraeum ticks were counted per animal and 7.0% of ticks were infected with the heartwater agent. it was found that the seropositivity of the animals was determined largely by the tick loads to which they were subjected and that the influence of the tick c. ruminantium infection r ...19873448573
the reservoir status of goats recovered from heartwater.experiments were conducted with creole goats and amblyomma variegatum ticks in guadeloupe to investigate whether it is possible to transmit cowdria ruminantium to susceptible hosts with nymphs fed in the larval stage on recovered goats. of 88 batches of larvae fed after the return of the goats' temperature to normal, or after challenge or immunosuppression, only the 9 batches of larvae fed during the febrile reaction, 2 batches applied 2 and 3 days respectively after recovery, and a single batch ...19873448574
Displaying items 201 - 300 of 1744