the natural control of heartwater vectors.socio-economic factors and environmental considerations have increasingly encouraged the search for methods of tick control other than acaricidal treatment. biological control management regimes have, so far, not proved to be sound replacements for acaricides. the major natural control methods employed successfully at present are host resistance and pasture management. the former has been extensively studied and utilized in a one-host-tick situation, and its potential specificity for the amblyom ...19873329337
hosts and population dynamics of amblyomma variegatum (acari: ixodidae) on guadeloupe, french west indies. 19883351867
abnormal development of amblyomma variegatum (acarina: ixodidae). 19883351871
the developmental success of amblyomma hebraeum and amblyomma marmoreum on the leopard tortoise, geochelone pardalis.the success of natural infestations of various life history stages of amblyomma hebraeum and amblyomma marmoreum on the leopard tortoise, geochelone pardalis, was compared. success was measured by the time taken for ticks to detach, as well as the percentage of ticks engorging and subsequently either moulting to the next life history stage or laying viable eggs. larvae of a. hebraeum were the only developmental stage not recovered. nymphae and female a. hebraeum were less successful in moulting ...19883353093
the use of domestic chickens as laboratory hosts of the larvae of the bont tick, amblyomma hebraeum.a comparison of attachment, engorgement and moulting success of amblyomma hebraeum larvae fed on domestic chickens and himalayan giant white rabbits indicates that chickens are better hosts than the rabbits. moreover the time needed for detachment of all engorged larvae is significantly less for chickens than for the rabbits. no evidence of induced immunity was found in chickens on re-infestation with larvae of a. hebraeum.19883353104
seasonal changes in feeding on cattle and reproduction by amblyomma americanum (acari: ixodidae) under field conditions. 19883357171
ticks parasitising the indian buffalo (bubalus bubalis) and their possible role in disease transmission.a total of 13 ixodid tick species, boophilus microplus, haemaphysalis bispinosa, haemaphysalis cornupunctata, haemaphysalis himalaya, heamaphysalis montgomeryi, hyalomma anatolicum anatolicum, hyalomma dromedarii, hyalomma marginatum isaaci, hyalomma (hyalommina) brevipunctata, hyalomma (hyalommina) hussaini, nosomma monstrosum, rhipicephalus haemaphysaloides, and r. turanicus were collected off 424 buffaloes from the northwestern states of india. ten tick species, amblyomma testudinarium, b. mi ...19883369083
kinetic properties of toxic protease inhibitors isolated from tick eggs.1. egg-toxins from rhipicephalus evertsi evertsi, boophilus microplus, boophilus decoloratus and hyalomma truncatum were found to be inhibitors of trypsin and in two cases also of chymotrypsin. 2. fast tight-binding and slow-binding inhibition were observed. 3. immunological identity of the toxins were assessed with ouchterlony immunodiffusion and elisa. 4. the protease content of b. decoloratus and amblyomma hebraeum tick eggs were determined by a linked enzyme assay. 5. the predictive value of ...19883391338
evidence for regurgitation by amblyomma americanum.western blot analysis of amblyomma americanum-derived midgut extracts using tick-resistant rabbit and guinea pig antisera demonstrated several unique polypeptides ranging from 7 to 355 kda. these polypeptides were not observed in similar blots of salivary gland extracts or serum from the respective host animals. the data from this study suggest that female a. americanum ticks regurgitate gut material during feeding. such a finding explains the ability of immunization with gut-derived preparation ...19883420794
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
biochemical studies on the eggs of amblyomma hebraeum.the isolation, characterization and kinetic properties of a toxic and non-toxic anti-protease from the eggs of a. hebraeum are compared with similar data obtained for eggs of other tick species. the biochemistry of various physiological processes in tick eggs is reviewed.19873448575
rearing and infection techniques for amblyomma species to be used in heartwater transmission experiments.techniques for the rearing of amblyomma species to be used in heartwater (cowdria ruminantium) transmission experiments are discussed. these involve the breeding and maintenance of infected and non-infected strains of ticks. they include the feeding of ticks on sheep, rabbits, mice, tortoises and guinea fowl.19873448576
the use of flumethrin 1% pour-on for the control of amblyomma spp. in various southern african countries.efficacy trials with flumethrin 1% pour-on were conducted in 9 different areas in 3 southern and central african countries against amblyomma hebraeum and a. variegatum on cattle. a dose volume of 10 ml/100 kg body mass applied at bi-weekly intervals provided excellent control of both tick species on their predilection sites, irrespective of locally and seasonally high tick pressure. the trial results demonstrate clearly that this new concept of tick control can be effectively applied in commerci ...19873448582
the effect of dipping on parasitic and free-living populations of amblyomma hebraeum on a farm and on an adjacent nature reserve.domestic stock on a farm 30 km north of grahamstown were treated with an acaricide at regular intervals over a period of several years. this resulted in a marked reduction in all stages of development of amblyomma hebraeum on kudu (tragelaphus strepsiceros), scrub hares (lepus saxatilis) and helmeted guinea fowl (numida meleagris) which were on the farm compared with the burdens of similar animals in an adjacent nature reserve. the populations of free-living larvae of a. hebraeum on this farm an ...19873448583
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 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
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
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
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
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
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
amblyomma calcaratum (acari: ixodidae), a central and south american tick, found in kentucky, usa. 19873820233
amblyomma variegatum (acari: ixodidae): population dynamics and hosts used during an eradication program in puerto rico. 19873820244
tick infestation in soldiers who were bivouacked in the perth region.we report observations on infestations with the tick, amblyomma triguttatum, in soldiers who were bivouacked in two areas near perth; 34% of 175 persons were infested with varying stages of the ectoparasite. most persons were infested with only one tick but some troops had multiple infestations. local skin reactions to tick-bites were frequent; they usually developed 24-48 h after removal of the tick and may indicate delayed hypersensitivity reactions. a small number of persons developed seconda ...19873821621
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
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: 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
a search for the epidemic typhus agent in ethiopian ticks.the presence of antibodies to rickettsia prowazeki in domestic animals from several parts of africa, and the isolation of this rickettsia from the blood of goats and sheep and from ticks off cattle or camels in ethiopia, led to the hypothesis that r. prowazeki in nature may occur in an extrahuman cycle involving ticks and domestic animals. this study attempted to recover r. prowazeki from 2 624 ticks (4 genera, 10 species) collected in central and southern ethiopia. the ticks were examined by th ...19734204491
[detection of amblyomma gemma dön. (ixodidae) in the crimea]. 19724271864
ultrastructure of haller's organ in the tick amblyomma americanum (l.). 19724334800
resistance of purebred brahman, hereford, and brahman times hereford crossbred cattle to the lone star tick, amblyomma americanum (acarina: ixodidae). 19744455918
some experiments on the transmission of theileria mutans (theiler, 1906) and theileria parva (theiler, 1904) by the ticks amblyomma variegatum (fabricius, 1794) and rhipicephalus appendiculatus neumann, 1901, in uganda. 19744607395
permeability of tarsal sensilla in the tick amblyomma americanum l. (acarina, ixodidae). 19724647364
the ecology of amblyomma cajennense a parasite of man and animals in trinidad. 19734777424
the effect of immersion in water on the immature stages of the ixodid ticks-rhipicephalus appendiculatus neumann 1901 and amblyomma variegatum fabricius 1794. 19734787718
fine structure of the central nervous system of dermacentor variabilis (say), amblyomma americanum (l.), and argas arboreus kaiser, hoogstraal, and kohls (ixodoidea). 19744852052
[amblyomma variegatum of african or antillean origin and rickettsia of the dermacentroxenus genus]. 19694933938
mate-seeking by female amblyomma maculatum (acarina: ixodidae) on a bovine. 19714938838
redescription of amblyomma fulvum neumann 1899 (acarina: ixodidae), a parasite of the giant anaconda in northern south america. 19725036198
a method of collecting nymphal and adult lone star ticks, amblyomma americanum (l.) (acarina: ixodidae), from woodlots. 19725036200
fine structural analysis of palpal receptors in the tick amblyomma americanum(l.). 19725042252
2,6-dichlorophenol, sex pheromone of the lone star tick.the compound 2,6-dichlorophenol was identified from female lone star ticks, amblyomma americanum, and is believed to be a sex pheromone of this arthropod. the natural occurrence of a chlorinated organic compound in a land animal is new. the presence of similar compounds of exogenous origin is common in animals, but efforts to implicate an outside source for the halogenated phenol have failed.19725054146
bionomics of the gopher tortoise tick, amblyomma tuberculatum marx. 19725057497
[notes on the ticks of sicily, with descriptions of hyalomma detritum and amblyomma variegatum]. 19715147924
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