TitleAbstractYear(sorted ascending)
attempts to feed amblyomma variegatum ticks on artificial membranes.feeding jars were used to feed nymphs of amblyomma variegatum on blood of goats or cattle. sterile blood was collected daily or weekly (kept at 4 degrees c or frozen until use), with addition either of heparin alone or of heparin and antibiotics/fungicide or of heparin, adenosine triphosphate and glutathione. membranes were made of a thin (0.12-0.32 mm) film of silicone mastic. blood in the jars was replaced twice a day, and reached a temperature of 39 degrees c in a waterbath before it became a ...19989668493
repeatability of the level of infestation by amblyomma variegatum ticks on creole cattle. 19989668494
seasonal variation of ticks on cattle in burkina faso.cattle of the sahel zebu peuhl breed from traditionally managed livestock herds in a representative area of north soudanese savana (with 400-900 mm of rainfall/year from may to september) located in the central land of burkina faso, were monitored over 12 months for tick and blood parasite. two species of ticks were found: amblyomma variegatum and hyalomma marginatum rufipes. h. m. rufipes was found on cattle all year round with a highest infestation rate in june characterized by means of 10 +/- ...19989668496
distribution, abundance, and seasonal activities of ticks collected from rodents and vegetation in south carolina.ixodid ticks were collected from live-trapped rodents and by flagging vegetation at sites in the piedmont, sandhills, coastal plain, and coastal zone of south carolina from may 1994 through december 1995. a total of 1,514 ticks was recovered from 237 live-trapped rodents. host-attached species included ixodes minor neumann (n = 818), dermacentor variabilis (say) (n = 346), amblyomma maculatum koch (n = 209), ixodes affinis neumann (n = 89), and ixodes scapularis say (n = 52). species of questing ...19989673934
prostaglandin e2 in the salivary glands of the female tick, amblyomma americanum (l.): calcium mobilization and exocytosis.a cholera toxin-sensitive, prostaglandin e2 (pge2) specific receptor has been identified in the plasma membrane fraction of tick salivary glands. in the present study, we report that stimulation of dispersed salivary glands of the lone star tick amblyomma americanum (l.) with 1 nm to 10 microm pge2 increased the intracellular concentration of inositol trisphosphate (ip3) in a dose-dependent manner. incubation of dispersed tissue with 1 nm to 10 microm pge2 also stimulated release of 45ca2+ from ...19989684330
investigating the epidemiology of heartwater (cowdria ruminantium infection) by means of a transmission dynamics model.a mathematical model of the transmission dynamics of cowdria ruminantium by the ixodid tick amblyomma hebraeum in the bovine host is developed and used to investigate the epidemiology of heartwater across a range of vector challenge. the processes described are supported by empirical data. the pattern of outcome measures (incidence, case-fatality and proportion of infected hosts) predicted agrees with those described anecdotally from field experience and empirical observation, and demonstrates t ...19989695100
host specificity of amblyomma cajennense (fabricius, 1787) (acari: ixodidae) with comments on the drop-off rhythm.the parasitic specificity of larval, nymph and adult amblyomma cajennense on six different host species: oryctolagus cuniculus, rattus norvegicus, gallus gallus domesticus, anas platyrhynchus, coturnix coturnix and streptopelia decorata is described. in terms of the numbers of larvae and nymphs recovered, o. cuniculus was the best host species. the modal day for drop-off of larvae and nymphs was day three for the mammal hosts, but variable in the birds. we conclude that adult a. cajennense have ...19989698869
detection of a spotted fever group rickettsia in amblyomma cajennense (acari: ixodidae) in south texas.thai tick typhus rickettsia (strain tt-118), a spotted fever group rickettsia of indeterminant pathogenicity, was isolated from a mixed pool of larval ixodes and rhipicephalus ticks collected from thailand in 1962. here we report the surprising finding of a spotted fever group rickettsia with closest sequence homology to the thai tick typhus rickettsia in amblyomma cajennense (f.) ticks from south texas. sequence analysis was performed on segments of 3 genes that differentiate rickettsial specie ...19989701930
population dynamics of immature amblyomma maculatum (acari: ixodidae) and other ectoparasites on meadowlarks and northern bobwhite quail resident to the coastal prairie of texas.a survey of ectoparasites from 219 meadowlarks conducted during 2 consecutive fall-winter periods in a coastal prairie found immature amblyomma maculatum koch to be the most abundant parasite. peak larval infestations occurred in december with 80-100% of collected birds infested and with a monthly mean of up to 34 larvae per bird. peak nymphal infestations occurred in february or march with 95-100% of birds infested and with a monthly mean of up to 11 nymphs per bird. seasonal dynamics of these ...19989701932
illustrated key to nymphs of the tick genus amblyomma (acari: ixodidae) found in the united states.a dichotomous identification key, with important characters illustrated by scanning electron micrographs, is provided for nymphs of the 9 species of the genus amblyomma occurring in the united states. species included are a. americanum (l.), a. cajennense (f.), a. dissimile koch, a. imitator kohls, a. inornatum (banks), a. longirostre (koch), a maculatum koch, a. rotundatum koch, and a. tuberculatum marx. notes on the geographical distributions, medical and veterinary importance, and nymphal sta ...19989701933
phospholipase a2 activity in salivary glands and saliva of the lone star tick (acari: ixodidae) during tick feeding.phospholipase a2 (pla2) activity levels in tick [amblyomma americanum (l.)] salivary glands and saliva were examined during tick feeding by using 14c-phosphatidylcholine as the substrate. saliva produced by stimulating female ticks to salivate with dopamine contains pla2 (ts-pla2) activity. the ts-pla2 activity level in saliva did not change significantly during tick feeding except for a decrease in the last rapid feeding phase (> 200 mg) and in replete ticks. phospholipase a2 activity was highe ...19989701935
interaction of entomopathogenic nematodes (steinernematidae) with selected species of ixodid ticks (acari: ixodidae).entomopathogenic nematodes, currently used for biological control of various insect pests, were tested for their ability to penetrate and kill replete females of several species of ticks including dermacentor variabilis (say), rhipicephalus sanguineus (latreille), amblyomma maculatum koch, and a. cajennense (f.). these species were found to be susceptible to the entomopathogenic nematodes, steinernema feltiae (filipjev) or s. riobravus (cabanillas & poinar), shown in previous studies in our labo ...19989701938
isolation of two functional retinoid x receptor subtypes from the ixodid tick, amblyomma americanum (l.).retinoid x receptors (rxr) play a central role in a variety of nuclear signaling pathways in both vertebrates and invertebrates. vertebrate rxrs are encoded by a multigene family whereas the insect rxr homologue, ultraspiracle (usp), is encoded by a single gene. to determine if acarines possess an rxr homologue similar to insect usps, we isolated cdnas encoding two distinct rxr genes, aamrxr1 and aamrxr2, from the ixodid tick, amblyomma americanum (l.). the dna binding domains share 95 and 87% i ...19989705073
demonstration of a carrier state for cowdria ruminantium in wild ruminants from africa.four wild african ruminants, eland (taurotragus oryx), giraffe (giraffa camelopardalis), kudu (tragephalus strepsiceros strepsiceros), and blue wildebeest (connochaetes taurinus), were experimentally infected with the rickettsia cowdria ruminantium, the tickborne agent causing heartwater in domestic ruminants. the infections were established, and c. ruminantium was transmitted to naive small ruminants by the vector amblyomma hebraeum when transmission attempts were made at days 128 (eland and wi ...19989706566
the travels of a lone star tick.a lone-star tick, amblyomma americanum, was found as a pedunculated lesion on the back of the arm of an 84 year old man in northern ireland. this was acquired on a visit to the usa. the tick is found mainly in texas and the ozark mountains of missouri, with scattered foci in other parts of southern usa. it is the vector of rocky mountain spotted fever. as worldwide travel becomes increasingly common, exotic parasites make occasional appearances in northern europe.19989708212
outbreak of rickettsia africae infections in participants of an adventure race in south africa.african tick-bite fever, caused by rickettsia africae and transmitted by amblyomma ticks, is an emerging rickettsiosis in southern africa. because of increased tourism to this area, several cases in tourists have been reported recently. we report 13 cases of r. africae infection diagnosed in france that occurred in competitors returning from an adventure race in south africa and compare our data with previously reported findings. most of our patients presented with fever, headache, multiple inoc ...19989709882
antibody to a cdna-derived calreticulin protein from amblyomma americanum as a biomarker of tick exposure in humans.the antibody responses of human and animal hosts were studied to determine the utility of antibody against recombinant tick calreticulin (rtc), a cdna-derived protein isolated from salivary glands of amblyomma americanum l., as a biologic marker of tick exposure. rabbits fed upon by either a. americanum or dermacentor variabilis say developed significant anti-rtc antibody responses, as measured by both elisa and immunoblot assay. in contrast, gerbils exposed to aedes aegypti did not develop anti ...19989715947
physician-diagnosed erythema migrans and erythema migrans-like rashes following lone star tick differentiate cases of physician-diagnosed erythema migrans and erythema migrans-like rashes associated with lone star tick (amblyomma americanum) bites.19989722725
a review of heartwater and the threat of introduction of cowdria ruminantium and amblyomma spp. ticks to the american mainland.heartwater, caused by the rickettsial agent cowdria ruminantium, is one of the most devastating livestock diseases in sub-saharan africa. in addition to domestic cattle, sheep, and goats, a variety of nondomestic species can acquire subclinical and clinical infections. recent epidemiologic findings that demonstrate a long-term host carrier state in domestic and wild ruminants, intrastadial transmission by the tick vectors (amblyomma spp.), vertical transmission of the agent from cows to their ca ...19989732023
immunization of rabbits with amblyomma hebraeum nymphal homogenates and implications for the host amplification system.immunochemical mechanisms involved in tick rejection by a host are not well documented. the role of serum globulins, and that played by the amplification system's humoral products (thrombin from the coagulation, plasmin from the fibrinolytic, and kallikrein from the kinin systems) in tick-resistant animal hosts have not yet been demonstrated. it is known, however, that factors c1, c3 and c5 of the complement system play a role in tick rejection, and that factors c3a and c5a are anaphylatoxins ca ...19989741053
ixodid tick infestations of wild birds and mammals on a game ranch in central province, zambia.ticks were collected at irregular intervals from december 1995 to november 1996 from wildlife on mtendere game ranch in the chisamba district of central province, zambia. total collections were made from two species of ground-nesting birds and 20 species of small and large mammals. thirteen species/subspecies of ixodid ticks were recovered. rhipicephalus appendiculatus was the most abundant, followed by boophilus decoloratus and rhipicephalus evertsi evertsi. small numbers of immature ticks of o ...19989741055
establishment of the tortoise tick amblyomma marmoreum (acari: ixodidae) on a reptile-breeding facility in florida.the tortoise tick amblyomma marmoreum koch was found to be established on a reptile facility in central florida. over a 5-mo period, 443 ticks were collected from tortoises, dogs, and vegetation. collections from hosts were primarily from 3 species of exotic tortoises, including leopard tortoises, aldabra tortoises, and yellow-footed tortoises. the total numbers of ticks present, the presence of all life stages, and the slow development of this species indicate that this is not a recent infestat ...19989775582
kinetics and cross-species comparisons of host antibody responses to lone star ticks and american dog ticks (acari: ixodidae).understanding of the animal antibody response to tick salivary gland proteins is necessary to identify candidate antibodies that may have use as species- and feeding-duration-specific biomarkers of tick exposure in humans. the kinetics of the humoral immune response of rabbits to challenge feeding by 2 tick species [amblyomma americanum (l.) and dermacentor variabilis (say)] was characterized by both enzyme-linked immunosorbent assay and immunoblot. western blot analysis revealed that rabbits pr ...19989775620
geographic distribution of ticks (acari: ixodidae) in michigan, with emphasis on ixodes scapularis and borrelia burgdorferi.a 12-yr (1985-1996) passive survey in michigan based upon tick submissions from citizens yielded 4,755 ticks of 21 species, 16 of which were probably indigenous in the state. three species of dermacentor [most common, d. variabilis say and d. albipictus (packard)]; 2 species of amblyomma [most common, a. americanum (l.)]; and 12 species of ixodes (most common, i. cookei packard and i. scapularis say), as well as haemaphysalis leporispalustris (packard), rhipicephalus sanguineus latreille, and th ...19989775623
ehrlichia chaffeensis in missouri ticks.a nested polymerase chain reaction specific for ehrlichia chaffeensis was used to attempt to amplify dna from extracts of 100 individual ticks collected from 13 counties in central missouri. seventeen of 59 amblyomma americanum and six of 41 dermacentor variabilis ticks exhibited the characteristic 389-basepair product. this supports the hypothesis that these tick species may be vectors of human monocytic ehrlichiosis.19989790445
natural coinfection of a white-tailed deer (odocoileus virginianus) population with three ehrlichia spp.the ticks amblyomma americanum and ixodes scapularis, strongly implicated vectors of ehrlichia chaffeensis and the human granulocytic ehrlichiosis (hge) agent, respectively, commonly are found on white-tailed deer (odocoileus virginianus). as deer can be infected with e. chaffeensis, the hge agent, and another ehrlichia-like organism, a deer population parasitized by both tick species in coastal georgia was tested for evidence of ehrlichia spp. infection using serologic, molecular, and culture t ...19989794627
the distribution of heartwater in the highveld of zimbabwe, 1980-1997.heartwater, the tick-borne disease caused by the rickettsia cowdria ruminantium has historically been confined to the southern and western lowvelds of zimbabwe. since 1986, however, cases of heartwater have been diagnosed with increasing frequency in the central and eastern regions of the previously heartwater-free highveld plateau. during the same period, collections of the two major tick vectors of heartwater in zimbabwe, amblyomma hebraeum and amblyomma variegatum, were made for the first tim ...19989809322
parasites of domestic and wild animals in south africa. xxxv. ixodid ticks and bot fly larvae in the bontebok national park.ixodid ticks were collected during february of each year from 1983-1992 from bontebok and grey rhebok in the bontebok national park, western cape province. when available other mammals as well as ground-nesting birds and leopard tortoises were examined. eleven tick species were recovered. rhipicephalus nitens followed by rhipicephalus glabroscutatum and an ixodes sp. (near i. pilosus) were the most abundant, while amblyomma marmoreum infested the widest host range. the larvae of three bot files ...19989809325
comment on "a possible explanation of the apparent breed-related resistance in cattle to bont tick (amblyomma hebraeum) infestations" by m.i. meltzer, veterinary parasitology 67 (1996) 275-279. 19989823067
a molecular and serologic survey of ehrlichia canis, e. chaffeensis, and e. ewingii in dogs and ticks from oklahoma.polymerase chain reaction and southern hybridization were used to survey for the presence of ehrlichia canis, ehrlichia chaffeensis, and ehrlichia ewingii in blood samples of 65 dogs that harbored ticks from northcentral and northeastern oklahoma. dog blood samples were also examined for antibodies against e. canis and e. chaffeensis, using an immunofluorescent antibody test. ten of 65 dogs (15.4%) examined were positive for ehrlichia spp. by pcr. four (6.2%) were positive for e. ewingii, 2 (3.1 ...19989831955
encephalitozoon-like microsporidia in the ticks amblyomma cajennense and anocentor nitens (acari: ixodidae).a encephalitozoon-like microsporidia was found in epithelial cells of the midgut and the salivary glands of amblyomma cajennense (f.) and anocentor nitens (neumann) that had fed on rabbits. ultrastructural studies demonstrated that all stages of the life cycle of the parasite occur in parasitophorous vacuoles and contain only 1 nucleus. the sporonts detach from the limiting membrane of the vacuole and divide by binary fission to produce the sporoblasts, each presenting a thickened electron-dense ...19989835698
experimental transmission of hepatozoon americanum vincent-johnson et al., 1997 to dogs by the gulf coast tick, amblyomma maculatum koch.experimental transmission of hepatozoon americanum to dogs was attempted with four ixodid ticks, viz., rhipicephalus sanguineus, amblyomma americanum, amblyomma maculatum and dermacentor variabilis. ticks that dogs ingested included some that were laboratory-reared and experimentally fed as nymphs on a dog with naturally occurring hepatozoonosis; other ticks were collected as replete or partially engorged larvae, nymphs and adults from dogs that had hepatozoonosis and natural infestations of tic ...19989877066
dna binding properties of the ecdysteroid receptor in the salivary gland of the female ixodid tick, amblyomma hebraeum.salivary gland degeneration in the female tick, amblyomma hebraeum koch (acari: ixodidae) is controlled by an ecdysteroid hormone. in an earlier study (mao, h., mcblain, w.a., kaufman, w.r., 1995. some properties of the ecdysteroid receptor in the salivary gland of the ixodid tick, amblyomma hebraeum. gen. comp. endocrinol. 99, 340-348), we demonstrated that a protein component of a salivary gland extract binds to ponasterone a (pon a) with high affinity (kd-1 nm), suggesting a tick ecdysteroid ...19989887511
[two cases of spotted fever group rickettsiosis contracted in southern parts of africa].a 40-year-old japanese male stayed in zimbabwe and developed a fever above 38 degrees c during which he noted a typical eschar in the lumbar region and also regional inguinal lymphadenopathy. although not conspicuous, erythematous eruptions accompanied by itching were observed on the face, trunk and lower extremities. after returning to japan and visiting our hospital, he was suspected of rickettsiosis and put on minocycline which gradually led to the improvement of the symptoms. immunofluoresce ...19989916419
population genetic structure of a three-host tick, amblyomma dissimile, in eastern venezuela.patterns of genetic variation for the tick amblyomma dissimile were analyzed from a total of 200 ticks collected on 12 toads (bufo marinus), 14 snakes (boa constrictor), and 8 lizards (iguana iguana) at 11 localities. the analyses were performed on electrophoretic data from 8 isozyme loci. mean heterozygosity per locus was 6% (+/-3.1) per population. differences in allelic frequencies among ticks from different individual hosts were the major source of genetic variability in this study. host spe ...19989920303
distributions of the vectors of heartwater, amblyomma hebraeum and amblyomma variegatum (acari: ixodidae), in zimbabwe.the tick vectors of heartwater (cowdria ruminantium infection) in zimbabwe, amblyomma hebraeum and amblyomma variegatum, historically were believed to be confined to the low-lying regions of the south and north-west of the country. however, country-wide surveys performed in 1975-1980 and 1988-1991 demonstrated that both species were also established in western parts of the highveld plateau and had started to encroach on the predominantly heartwater-free central and eastern highveld regions. to d ...199810030008
human ehrlichioses: newly recognized infections transmitted by ticks.human ehrlichioses are tick-borne infections caused by bacteria in the genus ehrlichia. human monocytic ehrlichiosis is caused by ehrlichia chaffeensis and human granulocytic ehrlichiosis is caused by an agent similar to ehrlichia equi. e. chaffeensis infects mononuclear phagocytes and is transmitted by lone star ticks (amblyomma americanum) found in the south central and eastern united states. the agent of human granulocytic ehrlichiosis infects mostly neutrophils, it transmitted by ixodes spec ...19989509259
ecdysteroid regulation of salivary gland degeneration in the ixodid tick, amblyomma hebraeum: a reconciliation of in vivo and in vitro observations.salivary gland degeneration in the female tick amblyomma hebraeum koch is triggered by an ecdysteroid (es) hormone. under both in vivo and in vitro conditions, degeneration requires 4 days for completion. in partially fed females that have fed beyond a "critical weight," the commitment period for salivary gland degeneration occurs between 24 and 48 h after removal from the host. although tissue degeneration begins within 24 h postengorgement, es titer as measured by radioimmunoassay (ria) does n ...19989473365
first isolation and cultivation of borrelia burgdorferi sensu lato from missouri.five borrelia burgdorferi sensu lato isolates from missouri are described. this represents the first report and characterization of such isolates from that state. the isolates were obtained from either ixodes dentatus or amblyomma americanum ticks that had been feeding on cottontail rabbits (sylvilagus floridanus) from a farm in bollinger county, mo., where a human case of lyme disease had been reported. all isolates were screened immunologically by indirect immunofluorescence by using monoclona ...19989431909
[partly automated in vitro feeding of adult amblyomma hebraeum]a reduction in the use of laboratory animals, such as rabbits and bovines, in the pharmaceutical industry and other institutions for breeding medically and economically important species of obligatory bloodsucking hard ticks (acari: ixodidae) is highly desirable. we report the successful feeding of males and females of the tropical tick amblyomma hebraeum in a partly automated, thus essentially maintenance-free in vitro system. the feeding data (body mass 1.85 degrees; egg conversion factor 0.37 ...199811178507
ticks of south carolina (acari: ixodoidea).county and host records are reported for 19 species of ticks from south carolina: amblyomma americanum, amblyomma maculatum, amblyomma tuberculatum, aponomma latum, boophilus annulatus, boophilus microplus, dermacentor albipictus, dermacentor variablis, haemaphysalis leporispalustris, ixodes affinis, ixodes brunneus, ixodes cookei, ixodes marxi, ixodes minor, ixodes scapularis, ixodes texanus, ixodes woodi, rhipicephalus sanguineus, and ornithodoros capensis. ixodes woodi is recorded from south ...199910672552
molecular individuality: polymorphism of salivary gland proteins in three species of ixodid tick.pooled tissue samples are frequently used in biochemical studies involving parasites in order to ensure that there is sufficient material for experimentation. a pooled sample is considered to represent the overall phenotypic characteristics of the investigated population. however, this will not be the case if there is a significant degree of molecular polymorphism among individuals in the sampled population. here we demonstrate marked differences in the protein profile of salivary glands among i ...199910737731
[isolation of rickettsia in vero cell culture].the diagnosis of spotted fever is based on characteristic signs and symptoms but requires laboratorial confirmation because of the possible differential diagnosis from other diseases like leptospirosis, enterovirus, meningococcemia and typhoid fever. laboratorial confirmation may be done by detection of specific antibodies which is possible only 5-10 days after the onset of the symptoms or by the isolation of rickettsiae from blood and/or skin biopsy and from ticks collected in the patient or in ...199910881078
report on ticks collected in the southeast and mid-west regions of brazil: analyzing the potential transmission of tick-borne pathogens to man.specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the southeast and mid-west regions of brazil. nine species of amblyommidae were identified: anocentor nitens, amblyomma cajennense, amblyomma ovale, amblyomma fulvum, amblyomma striatum, amblyomma rotundatum, boophilus microplus, boophilus annulatus, and rhipicephalus sanguineus. the potential of these tick species as transmitters of pathogens to man was analyzed. a flaviviridade flavivirus ...199910881097
profile of the ecdysteroid hormone and its receptor in the salivary gland of the adult female tick, amblyomma hebraeum.we examined the hemolymph ecdysteroid titer (by radioimmunoassay) and profile of the ecdysteroid receptor (ecr/usp; by [3h]ponasterone a binding, gel mobility shift assay, western blot) in the salivary gland of the ixodid tick, amblyomma hebraeum koch (acari: ixodidae) throughout the tick feeding period and first 6 days post-engorgement. throughout the slow phase of feeding, the hemolymph ecdysteroid titer was approximately 18 pg/microliter. the titer peaked at approximately 52 pg/microliter dur ...199910070743
molecular cloning of camp-dependent protein kinase catalytic subunit isoforms from the lone star tick, amblyomma americanum (l.).the salivary glands of ixodid ticks are central to tick feeding and to survival during off-host periods. they produce and secrete a number of molecules critical to maintaining the complex host-vector interface and to maintaining osmotic balance. we have previously shown that a cyclic amp-dependent protein kinase (capk) is involved in the mechanism of salivary gland secretion. we have now cloned cdnas encoding three isoforms of the catalytic subunit (capk-c) of the capk from amblyomma americanum, ...199910070744
naturally occurring hepatozoonosis in coyotes from oklahoma.nine of 16 free-ranging coyotes (canis latrans) from central oklahoma (usa) had naturally acquired infections of hepatozoon americanum. infections were confirmed by recognition of tissue stages closely resembling h. americanum in skeletal and cardiac muscle. at the time coyotes were collected they were infested with a variety of ticks, including adult gulf coast ticks (amblyomma maculatum). we propose that the high prevalence of h. americanum in this small sample of free-ranging coyotes and the ...199910073352
novel ehrlichia organism (rickettsiales: ehrlichieae) in white-tailed deer associated with lone star tick (acari: ixodidae) parasitism.polymerase chain reaction (pcr) evidence of a novel ehrlichia organism was found recently in wild white-tailed deer, odocoileus virginianus zimmermann, and lone star ticks, amblyomma americanum l., from the southeastern united states. to evaluate whether lone star tick parasitism was associated with the presence of this novel ehrlichia organism in deer, 2 retrospective studies were conducted using specific nested pcr to test archived deer serum samples. the 1st study of 150 serum samples collect ...199910083757
phylogeny of the hard ticks (ixodidae) inferred from 18s rrna indicates that the genus aponomma is paraphyletic.we examined the phylogeny of ticks (acari:parasitiformes:ixodida) and their closest known mite relatives (acari:parasitiformes:mesostigmata and holothyrida) using 18s rrna sequences. in our analyses, we included sequences from 36 taxa. sequences for 13 hard ticks (family ixodidae), 5 soft ticks (family argasidae), and 2 mesostigmatid mites were obtained from the genbank database and we generated sequences for 15 hard ticks and 1 holothyrid mite. ten of these tick species were endemic to australi ...199910191073
molecular cloning and characterization of the ehrlichia chaffeensis variable-length pcr target: an antigen-expressing gene that exhibits interstrain variation.a clone expressing an immunoreactive protein with an apparent molecular mass of 44 kda was selected from an ehrlichia chaffeensis arkansas genomic library by probing with anti-e. chaffeensis hyperimmune mouse ascitic fluid. nucleotide sequencing revealed an open reading frame (orf) capable of encoding a 198-amino-acid polypeptide. the orf contained four imperfect, direct, tandem 90-bp repeats. the nucleotide and deduced amino acid sequences did not show close homologies to entries in the molecul ...199910203503
[experimental transmission of crimean-congo hemorrhagic fever virus: role of 3 vector species in the maintenance and transmission cycles in senegal].in this article, we published the role of three species of ticks amblyomma variegatum (fabricius, 1974), hyalomma marginatum rufipes (koch, 1844) and hyalomma truncatum (koch, 1844) in the maintenance and transmission of the cchf virus. the imagos of these species were infected by intracoelomic route. vertical transmission (transtasial and transovarial) and horizontal transmission for different stases were studied by isolation on newborn mice, polymerase chain reaction, indirect immunofluorescen ...199910229934
responses of three species of adult ticks (acari: ixodidae) to chemicals in the coats of principal and minor laboratory bioassays, host-seeking adult blacklegged ticks, ixodes scapularis say, lone star ticks, amblyomma americanum (l.), and american dog ticks, dermacentor variabilis (say), were exposed to substances from the pelage of dogs and white-tailed deer, odocoileus virginianus (zimmermann). male a. americanum exhibited an arrestant response to all samples of deer tarsal gland substances tested, whereas female a. americanum, female i. scapularis, and male and female d. variabilis responded to ...199910337091
attachment sites of four tick species (acari: ixodidae) parasitizing humans in georgia and south carolina.from june 1995 through january 1998, 677 tick specimens were submitted by 521 humans from 14 states. analysis was limited to specimens originating in georgia and south carolina, representing 87.3% of total submissions. attachment sites were specified in 367 specimens (62.3%). the american dog tick, dermacentor variabilis (say), a vector of the agent of rocky mountain spotted fever, favored the head and neck in 59% of attached specimens. the lone star tick, amblyomma americanum (l.), a strongly i ...199910337108
palp-splaying behavior and a specific mouthpart site associated with active water vapor uptake in amblyomma americanum (acari: ixodidae).ticks actively absorb water vapor from unsaturated air via their mouthparts. a wax technique was used to cover select areas of the mouthparts of the lone star tick, amblyomma americanum (l.), to examine whether a specific site is involved in uptake. covering dorsal, ventral, and distal regions failed to inhibit uptake, whereas wax applied to the proximal region, specifically the hypostome-cheliceral junction, blocked water absorption. a novel occurrence of a palp-splaying behavior was observed d ...199910337109
population dynamics of ticks on indigenous cattle in a pastoral dry to semi-arid rangeland zone of uganda.studies on seasonality and population dynamics of ticks on indigenous cattle and their crosses (calves) were carried out in buruli ranching scheme, nabiswera, luwero district of uganda on three treatment groups of animals: group 1 (twice a week dipping), group 2 (once a month dipping) and group 3 (no tick control). during this study, four major species of ticks of economic importance were recorded in decreasing order of abundance: rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, ambl ...199910353189
evaluation of 16s, map1 and pcs20 probes for detection of cowdria and ehrlichia species.a panel of 16s ribosomal rna gene probes has been developed for the study of the epidemiology of heartwater; five of these detect different cowdria genotypes, one detects five distinct genotypes; one detects any group iii ehrlichia species other than cowdria and one detects any group ii ehrlichia species. these probes have been used on pcr-amplified rickettsial 16s rrna genes from over 200 amblyomma hebraeum ticks. control ticks were laboratory-reared and either uninfected or fed on sheep experi ...199910355799
the life cycle of amblyomma neumanni ribaga, 1902 (acari: ixodidae) in the laboratory.a colony of amblyomma neumanni was started with engorged females collected from cattle in the province of salta (24 degrees 51's, 65 degrees 33'w), argentina. the larvae and nymphs were fed on rabbits and the adults on calves. the non-parasitic stages were maintained in darkness at 27 +/- 1 degrees c and 83-86% rh. the life cycle (pre-feeding period not tested) had a mean duration of 205.7 days. the mean time (days) for the different phases of the cycle were as follows: feeding of females 8.8, p ...199910356766
immune responses to dermatophilus congolensis infections.complex mechanisms underly the establishment of dermatophilosis, an exudative and proliferative skin disease of ruminants. this multicomponent system involves the bacterium dermatophilus congolensis, transmission by various routes including flies, host genetic factors and immunosuppression by amblyomma variegatum ticks. here, nick ambrose and colleagues summarize recent evidence for an association between a. variegatum and severe chronic dermatophilosis in cattle. breed-based differences in resi ...199910377534
canine hepatozoonosis: comparison of lesions and parasites in skeletal muscle of dogs experimentally or naturally infected with hepatozoon americanum.we report previously undescribed, early lesions in skeletal muscle of dogs experimentally infected with hepatozoon americanum by ingestion of laboratory-reared, infected amblyomma maculatum. the earliest muscle lesion was recognized at the first interval of examination 3 weeks following exposure. the lesion consisted of a large, modified host cell whose cytoplasm frequently contained a demonstrable parasite. in skeletal muscle, the cell was consistently located between muscle fibers or in loose ...199910384901
susceptibility and carrier status of impala, sable, and tsessebe for cowdria ruminantium infection (heartwater).three species of wild african ruminants, impala (aepyceros melampus), sable (hippotragus equinus), and tsessebe (damaliscus lunatus), were experimentally inoculated with in vitro culture-derived cowdria ruminantium organisms, the tick-borne causative agent of heartwater in domestic ruminants, to determine their susceptibility to infection. no clinical disease was observed in any of the ruminants. however, c. ruminantium was detected in the sable by the transmission of heartwater to susceptible s ...199910386439
tick-borne rickettiosis in guadeloupe, the french west indies: isolation of rickettsia africae from amblyomma variegatum ticks and serosurvey in humans, cattle, and goats.twenty-seven rickettsiae were isolated and/or detected from 100 amblyomma variegatum ticks collected on guadeloupe in the french west indies. in this study, the polymerase chain reaction procedure appeared to be more sensitive in detecting rickettsiae in ticks than the shell-vial technique. sequencing a portion of the outer membrane protein a-encoding gene showed that these rickettsiae appeared to be identical to rickettsia africae, a member of the spotted fever group rickettsiae recently descri ...199910403315
wild birds as hosts of amblyomma cajennense (fabricius, 1787) (acari: ixodidae).we evaluated the prevalence, mean intensity and relative density of ticks in 467 wild birds of 67 species (12 families) from forest and cerrado habitats at two protected areas of minas gerais, between march and september 1997. ticks collected (n=177) were identified as larvae and nymphs of amblyomma cajennense and four other species of amblyomma. we report for the first time 28 bird species as hosts of the immature stages of a. cajennense, demonstrating the lack of host specificity of the larvae ...199910419381
seroepidemiologic studies on babesia equi and babesia caballi infections in brazil.horses from six stud farms representing the most frequent types of horse breeding in brazil were tested for babesia antibodies by the ifa test. the farms are located at the tropic of capricorn at an altitude of 472-715 m where temperatures below 0 degrees c may occur. horses of conventional stud farms were infested with dermacentor nitens, amblyomma cajennense, and boophilus microplus. infestation with bo. microplus was associated with direct or indirect contact of horses with cattle, and was no ...199910447188
theileria sp. infections associated with bovine fatalities in the united states confirmed by small-subunit rrna gene analyses of blood and tick samples.theileria sp.-specific small subunit (ssu) rrna gene amplification confirmed the presence of the organism in cattle and in amblyomma americanum and dermacentor variabilis ticks collected from a cattle herd in missouri. blood from the index animal had type a and type d theileria ssu rrna genes. the type d gene was also found in blood from two cohort cattle and tick tissues. the type a ssu rrna gene was previously reported from bovine theileria isolates from texas and north carolina; the type d ge ...199910449501
evidence of rickettsial spotted fever and ehrlichial infections in a subtropical territory of jujuy, argentina.between november 1993 and march 1994, a cluster 6 pediatric patients with acute febrile illnesses associated with rashes was identified in jujuy province, argentina. immunohistochemical staining of tissues confirmed spotted fever group rickettsial infection in a patient with fatal disease, and testing of serum of a patient convalescing from the illness by using an indirect immunofluorescence assay (ifa) demonstrated antibodies reactive with spotted fever group rickettsiae. a serosurvey was condu ...199910463693
comparison of methods for introducing and producing artificial infection of ixodid ticks (acari: ixodidae) with ehrlichia chaffeensis.only 29.5 +/- 8.91% of engorged amblyomma americanum (l.) nymphs that we inoculated with ehrlichia chaffeensis molted successfully to adults compared with 75.8 +/- 7.46% of engorged nymphs that were not inoculated. however, 65.4 +/- 6.02% of unfed nymphs of this species were exposed for 2 h to e. chaffeensis suspension introduced to them through glass capillaries gained weight. these nymphs were placed on rabbits, and approximately 50% of them completed their feeding and molted successfully to a ...199910467766
squalene: a naturally abundant mammalian skin secretion and long distance tick-attractant (acari: ixodidae).squalene is a naturally occurring lipid on mammalian skin and is an attractant to the lone star tick, amblyomma americanum (l.). in this study, we compared squalene to the standard tick-attractants, benzaldehyde, isobutyric acid, methyl salicylate, nonanoic acid, and o-nitrophenol identified as active ingredients of tick aggregation-attachment pheromones and determined its effectiveness in field and laboratory settings at varying distances. squalene was detected from 1/4 m greater than the stand ...199910467784
toxicity of neem seed oil (azadiracta indica) against the larvae of amblyomma variegatum a three-host tick in cattle.the in vitro toxicity of neem seed oil (azadiracta indica, family: meliaceae, 'dogon yaro' in hausa -language) was tested against the larvae of a three-host tick, amblyomma variegatum (family: ixodidae or hard tick) parasitic to cattle commonly found in nigeria. undiluted neem oil (100% concentration) was found to kill all (100% mortality) the larvae after 48 h. the toxicity was concentration and time dependent.199910479769
transmission of the blood parasite hemolivia mariae between its lizard and tick hosts.the haemogregarine hemolivia mariae is found in the erythrocytes of a natural population of the lizard tiliqua rugosa. it infects two tick species, amblyomma limbatum and aponomma hydrosauri, which parasitise lizards. in laboratory experiments, engorged amb. limbatum nymphs from infected lizards transmitted the haemogregarine to uninfected lizards significantly more often than engorged ap. hydrosauri nymphs. dissections of larvae and nymphs of both species fed on the same infected hosts showed t ...199910494815
serologic study of the prevalence of rickettsiosis in yucatán: evidence for a prevalent spotted fever group rickettsiosis.because of the discovery of a spotted fever group rickettsiosis with signs and symptoms similar to dengue fever in yucatan, mexico, immunofluorescence assay (ifa) serology was performed on sera from 390 persons selected from a representative geographic distribution of rural yucatan to detect antibodies reactive with rickettsia rickettsii, r. akari, a thai strain (tt-118) that is most closely related to a rickettsia identified in amblyomma cajennense ticks in southern texas, and r. typhi. the ifa ...199910497980
cowdria ruminantium infection in ticks in the kruger national amblyomma hebraeum ticks, the principle vector of heartwater (cowdriosis) of domestic ruminants in southern africa, were collected in pheromone traps placed in kruger national park, an exclusively wildlife sanctuary in south africa. these ticks transmitted cowdria ruminantium, the rickettsial agent causing heartwater, to a susceptible goat, resulting in acute, fatal disease. c ruminantium was isolated in bovine endothelial cell culture from the plasma of this animal during the febrile stag ...199910515616
[african rickettsia infections].epidemiology: african rickettsiasis is transmitted by rickettsia africae, a cattle tick. amblyomma spp. is an emerging rickettsiasis in sub-sehalian afric described in 1992. seroepidemiology studies conducted in africa show that it is probably the most widespread rickettsiasis in the sorld. in addition, the development of tourist activities in southern african countries has led to an increase in the number of reported cases in subjects returning from endemic areas. a high serprevalence of anti r ...199910518970
ticks and antibodies to borrelia burgdorferi from mammals at cape hatteras, nc and assateague island, md and va.results of a survey for ixodid ticks and/or serum antibodies to borrelia burgdorferi from 14 species of small to large mammals from eastern coastal areas of the united states are presented. most samples were obtained from july 1987 through june 1989 (excluding december-march) at 3 locales: assateague is. national seashore, worcester co., md., and accomack co., va. (approximately 38 degrees 05' n 75 degrees 10' w), and cape hatteras national seashore, dare co., nc (approximately 35 degrees 30' n ...199910534951
prevalence of cowdria ruminantium infection in amblyomma hebraeum ticks from heartwater-endemic areas of zimbabwe.analysis of the transmission dynamics of cowdria ruminantium, the tick-borne rickettsial agent of heartwater in ruminants, requires accurate measures of infection in vector populations. to obtain these, amblomnia hebraeum ticks were collected at two heartwater-endemic locations in the lowveld and highveld regions of zimbabwe and assessed for c. ruminantium infection with specific polymerase chain reaction (pcr) and dna probe detection assays. at the lowveld site, 11.2% (50/446) of adult ticks an ...199910579452
ticks feeding on humans: a review of records on human-biting ixodoidea with special reference to pathogen this article, literature records of argasid and ixodid ticks feeding on humans worldwide are provided in view of increased awareness of risks associated with tick bites. ticks can cause paralyses, toxicoses, allergic reactions and are vectors of a broad range of viral, rickettsial, bacterial and protozoan pathogens. approximately 12 argasid species (argas and ornithodos) are frequently found attached to humans who intrude into tick-infested caves and burrows. over 20 ixodid tick species are o ...199910581710
infection rates of amblyomma americanum (acari: ixodidae) by ehrlichia chaffeensis (rickettsiales: ehrlichieae) and prevalence of e. chaffeensis-reactive antibodies in white-tailed deer in southern indiana, monitor the percentage and stability of ehrlichia chaffeensis-infected ticks in southern indiana over time, pools of amblyomma americanum (l.) ticks were screened for infection in southern indiana for a 2nd time. nested polymerase chain reaction (with 6% dmso included only in the 2nd reaction) was performed on 920 ticks in pools of 5 individuals from 9 sites (5 sites previously examined and 4 new ones) in 6 counties. the average minimum infection rate for all sites for 1997 was 1.6%, lower th ...199910593071
parasites in cross-bred pigs in the upper east region of ghana.a cross-sectional study was carried out in the upper east region (uer) of ghana in order to estimate the prevalence of parasitic infections in local cross-bred pigs. out of 60 villages with a human population of 200-1000 inhabitants, 10 villages were randomly selected for the study. the number of pigs varied from 50 to 200 pigs per village. in total 259 faecal samples from growers were collected and examined. ninety-one percent of the animals excreted parasite eggs. among these the prevalence of ...199910628701
parasites of domestic and wild animals in south africa. xxxvii. ixodid ticks on cattle on kikuyu grass pastures and in valley bushveld in the eastern cape province.individual calves, exposed to infestation for 14 d on dry-land kikuyu grass pastures on the coast near alexandria, were slaughtered at approximately monthly intervals over a period of 2 years and examined for ticks. although seven species were recovered total tick burdens were for the most part low. changing the acaricide with which other cattle on the farm, but not the survey calves, were treated from an organophosphate-based compound to a synthetic pyrethroid resulted in a marked sustained red ...199910631707
the occurrence of theileria and cowdria parasites in african buffalo (syncerus caffer) and their associated amblyomma hebraeum ticks.the polymerase chain reaction and oligonucleotide probing were used to detect theileria and cowdria species in dna extracted from blood and ticks recovered from 24 african buffalo during a gamecapture operation in the kruger national park, south africa. species-specific probing indicated that all but one of the buffalo were carrying at least one theileria species. indirect fluorescent antibody (ifa) serology indicated that all animals had been exposed to theileria parva infection but only 33% we ...199910631711
sporogonic development of hepatozoon americanum (apicomplexa) in its definitive host, amblyomma maculatum (acarina).light microscopic observations of the sporogonic development of hepatozoon americanum are described in its acarine host, amblyomma maculatum. laboratory-reared nymphal ticks were fed on 2 dogs infected with h. americanum. nymphal ticks were sampled daily, starting 3 days after being placed on a parasitemic dog, until 18 days after infestation (pi), and then every 3 or 4 days until replete nymphs molted. ticks were examined as unstained wet mounts and hematoxylin-eosin-stained paraffin sections. ...199910647032
responses of the tropical bont tick, amblyomma variegatum (fabricius), to its aggregation-attachment pheromone presented in an air stream on a servosphere.male amblyomma variegatum ticks feeding on a host release a mixture of o-nitrophenol and methyl salicylate which serves to attract conspecifics. the behavioural responses of a. variegatum on a servosphere to these volatiles presented in an air stream are detailed here. in still air, ticks walked on all eight legs, but with long halts. in contrast, the air stream caused continuous walking and induced a reaching response where the forelegs actively sampled the air. such reaching increased the angu ...200010659046
ultrastructure studies on post-oocyst development of the lizard hemogregarine hemolivia mariae in the tick amblyomma limbatum.the ultrastructural features of the development of hemolivia mariae, a blood parasite of the australian lizard, tiliqua rugosa, from sporokinetes to sporozoites in their vector tick amblyomma limbatum are described. sporokinetes, released from oocysts, re-establish themselves in tick-gut epithelial cells within a parasitophorous vacuole, the wall of which becomes evaginating and anastomosing and is underlined extensively by endoplasmic reticulum. the sporozoites forming within the encysting spor ...200010894472
range expansion of the tick amblyomma triguttatum triguttatum, an australian vector of q fever.the tick amblyomma triguttatum triguttatum has previously been reported from western australia, queensland and new south wales. a viable population of this species, including all developmental stages, has now been discovered on the southern end of yorke peninsula, south australia. species determination was carried out morphologically and using 18s and 16s rrna. the data for 16s rrna are the first published for this species. amblyomma t. triguttatum is significant through its involvement in the n ...200010899523
a review of the ticks (acari, ixodida) of brazil, their hosts and geographic distribution - 1. the state of rio grande do sul, southern brazil.a review of the ticks (acari, ixodida) of the state of rio grande do sul, southern brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. the ticks: argas miniatus (poultry), ixodes loricatus (opossums), amblyomma aureolatum (dogs), a. calcaratum (anteaters), a. cooperi (capybaras), a. nodosum (anteaters), a. tigrinum (dogs) (neotropical) and rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, afrotropical) were ...200010904399
the '4-poster' passive topical treatment device to apply acaricide for controlling ticks (acari: ixodidae) feeding on white-tailed deer.a '4-poster' device that attracts white-tailed deer to a bait source, and as they feed, allows a self-application of a pesticide to the head, ears, and neck to control ticks was designed, constructed, and tested. the device consists of a central bin containing bait to attract deer and two feeding and application stations. these stations each have one bait port and two vertical pesticide-impregnated applicator rollers. this design allows unrestricted vertical retraction of the head to minimize in ...200010916301
distribution of ehrlichia chaffeensis (rickettsiales: rickettsiaeceae) in amblyomma americanum in southern indiana and prevalence of e. chaffeensis--reactive antibodies in white-tailed deer in indiana and ohio in continue monitoring the prevalence and distribution of ehrlichia chaffeensis (rickettsiales: rickettsiaeceae) in southern indiana, a total of 498 amblyomma americanum (l.) ticks (262 adults and 292 nymphs) was collected from five southern indiana counties during may and june 1998. ticks were pooled and examined for the presence of e. chaffeensis using nested polymerase chain reaction and primers specific for the 16s rrna gene of e. chaffeensis. the average minimum infection rate for adult tic ...200010916302
new host and distribution record of amblyomma javanense (acari: ixodidae) in thailand.amblyomma javanense (supino) was collected from a malayan pangolin (manis javanica desmarest) and a wild boar (sus scrofa l.) from tak province on the western boundary of thailand along the myanmar (burma) border. to date, this tick species has not been recorded from this area and from a wild boar.200010916309
a state-by-state survey of ticks recorded from humans in the united states.based on tick specimens accessioned into the u.s. national tick collection, the species of ticks recorded as ectoparasites of humans are documented and compared for 49 u.s. states. a total of 44 tick species was recorded as parasites of humans, consisting of 11 species of soft ticks (argasidae) and 33 species of hard ticks (ixodidae). four of the hard tick species are not native to the u.s. and were removed from travelers returning from foreign destinations. therefore, we record 40 of the 84 spe ...200010925803
ultrastructure of hemolivia mariae gamonts in the blood of the lizard tiliqua rugosa and their development to oocyst stage in the tick amblyomma limbatum.the ultrastructural features of the development of hemolivia mariae from intra-erythrocytic gamonts in their host, the australian lizard tiliqua rugosa, to oocysts containing sporokinetes in their vector, the tick amblyomma limbatum, are described. mature intra-erythrocytic gamonts, as well as gamonts ingested by the tick were encased in a thick (30 nm) capsule with distinct suture sites at each of the two apices. in the only image of a presumed syzygy, both partners were still encased. further ...200010935907
attempted transmission of ehrlichia chaffeensis among white-tailed deer by amblyomma maculatum.a deer was needle-exposed intravenously to ehrlichia chaffeensis (rickettsiales: ehrlichieae) in canine macrophage (dh82) cells and 7 days later was infested with laboratory-reared amblyomma maculatum (koch) (acari:ixodidae) nymphs for acquisition feeding. after molting, the adult ticks were allowed to feed on a naive deer. the organism was reisolated from the needle-exposed deer by cell culture and e. chaffeensis dna was detected in the deer's blood by pcr. similar isolation/recovery techniques ...200010941753
prevalence and intensity of the blood parasite hemolivia mariae in a field population of the skink tiliqua rugosa.the impacts of virulent parasites on humans or domestic animals are well documented. less is known of the impact of parasites in natural host-parasite associations. a population of the australian sleepy lizard tiliqua rugosa is infected with the blood microparasite hemolivia mariae, which is transmitted by the ectoparasitic tick amblyomma limbatum. in most infected lizards a very small proportion, usually < 1%, of red blood cells are infected. a study of the prevalence of the microparasite in th ...200010952265
introduction of potential heartwater vectors and other exotic ticks into florida on imported reptiles.following the discovery of establishment of the african tortoise tick amblyomma marmoreum in florida, the present study was undertaken to determine the extent of introduction of exotic ticks into florida on imported reptiles. exotic ticks were identified on 29 (91%) of 32 reptile premises in 18 counties of florida. the ticks, found on a variety of imported tortoises, snakes, and monitor lizards, belonged to 4 amblyomma species (a. marmoreum, amblyomma nuttalli, amblyomma sabanerae, and amblyomma ...200010958443
prevalence of ehrlichia ewingii in amblyomma americanum in north carolina. 200010979750
influence of temperature and relative humidity on the moulting success of amblyomma limbatum and aponomma hydrosauri (acari: ixodidae) larvae and nymphs.this study compared the duration of the moulting periods of engorged larvae and nymphs of the ixodid ticks, amblyomma limbatum and aponomma hydrosauri, at different temperature/relative humidity regimes, and examined the relationships between the engorged weight of ticks and their weights after moulting. the results showed that for each species, there was a significant relationship between the weights of unfed nymphs and engorged larvae, and the weights of unfed adults and engorged nymphs. the w ...200010980285
prostaglandin e(2)-stimulated secretion of protein in the salivary glands of the lone star tick via a phosphoinositide signaling pathway.previous studies identified a prostaglandin e(2) (pge(2)) receptor in the salivary glands of partially fed female lone star ticks, amblyomma americanum (l.). in the present studies, protein secretion from dispersed salivary gland acini was shown to be specific for pge(2), as compared with pgf(2alpha) or the thromboxane analog u-46619, in accordance with their respective binding affinities for the pge(2) receptor. furthermore, the selective pge(2) ep1 receptor agonist, 17-phenyl trinor pge(2), wa ...200010989297
population dynamics of the free-living stages of amblyomma cajennense (fabricius, 1787) (acari: ixodidae) on pastures of pedro leopoldo, minas gerais state, brazil.a study on the population behavior of amblyomma cajennense larvae, nymphs and adult free-living stages was carried out in pedro leopoldo county, minas gerais state, brazil, from july 1995 to july 1997. larvae were collected from pasture from april to october using the technique of drag sampling with flannelette. the maximal larval population was observed during autumn (may) representing, respectively, 48 and 82% of the total numbers recovered during the first and the second years of the experime ...200010996741
ticks and tick-borne disease systems in space and from space.analyses within geographical information systems (giss) indicate that small- and large-scale ranges of hard tick species (ixodidae) are determined more by climate and vegetation than by host-related factors. spatial distributions of ticks may therefore be analysed by statistical methods that seek correlations between known tick presence/absence and ground- or remotely-sensed (rs) environmental factors. in this way, local habitats of amblyomma variegatum in the caribbean and ixodes ricinus in eur ...200010997208
feasibility of controlling ixodes scapularis ticks (acari: ixodidae), the vector of lyme disease, by parasitoid augmentation.a theoretical analysis of the feasibility of controlling tick populations (ixodidae) by the release of reared ixodiphagus parasitoids in tick ecosystems yielded promising results. the analysis suggested that if reasonable progress could be made in mass-rearing the parasitoids, it would be possible to control the blacklegged tick, ixodes scapularis (say), the vector of lyme disease, by this biological control procedure. lyme disease has become the most important vector-borne disease in the united ...200011004774
production of pheromones by artificially fed males of the tick amblyomma maculatum (acari: ixodidae).aggregation-attachment pheromones are produced only by male ticks of the genus amblyomma that have imbibed blood for at least 8 d from their mammalian hosts. this report demonstrates that production and release of aggregation-attachment pheromones by amblyomma maculatum (koch) males can be induced in vitro by using nonblood media, artificially introduced through capillary tubes, into the male ticks. the presence of these pheromones is demonstrated by using both biological observations on bovine ...200011004791
ticks (acari: ixodidae) associated with rural dogs in uruará, eastern amazon, brazil.a survey of 124 dogs for ticks was conducted from august to november 1998 in 68 small farms of uruará municipality in eastern amazon-brazil. we collected 55 ticks from 18 dogs (14.5%). amblyomma oblongoguttatum koch, amblyomma ovale koch, and amblyomma cajennense (f.) were found on nine, six, and one dog, respectively. fourteen small farms (20.5%) had at least one dog with ticks.200011004794
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