detection of cowdria ruminantium in blood and bone marrow samples from clinically normal, free-ranging zimbabwean wild ungulates.cowdria ruminantium causes severe, often fatal disease in domestic ruminants, whereas wildlife species usually are not affected. blood and bone marrow samples from healthy, free-ranging zimbabwean ungulates were taken during translocation from areas harboring amblyomma ticks and tested for the presence of c. ruminantium, using a pcr assay based on the c. ruminantium map1 gene. positive reactions were obtained in tsessebe (damaliscus lunatus), waterbuck (kobus ellipsiprymnus), and impala (aepycer ...19957494060
the detection of antibodies cross-reacting with cowdria ruminantium in the sera of domestic ruminants in regions of south africa where amblyomma hebraeum does not occur.high levels of seropositivity, in all probability attributable to ehrlichia, were recorded in the serum of domestic ruminants throughout districts in south africa where amblyomma hebraeum, the vector of the heartwater agent, does not occur. the antibodies, detected with the indirect fluorescent antibody (ifa) and the indirect elisa tests, cross-reacted with cowdria ruminantium, which was used as antigen in both tests. a combination of the ifa and elisa tests, currently employed to detect antibod ...19947501358
seasonal incidence and hemoparasite infection rates of ixodid ticks (acari: ixodidae) detached from cattle in costa determine the tick species hindering the cattle industry in costa rica and to assess infection rates of ticks with three important hemoparasite species, cattle were monitored during a period of six months (october 1992-march 1993). four farms were located in the dry pacific region of the canton of tilarán and a fifth farm on the slopes of the poás volcano in a cool tropical cloud-forest ecosystem. on each farm 3 to 5 animals of 6 to 24 months of age were selected at random. all ticks were rem ...19947501871
effects of tick infestation and tick-borne disease infections (heartwater, anaplasmosis and babesiosis) on the lactation and weight gain of mashona cattle in south-eastern zimbabwe.the effects of ticks and tick-borne disease infections on the lactation and weight gain of mashona cattle were studied at mbizi quarantine station in the south-eastern lowveld of zimbabwe. twenty-nine mashona cows were allocated to 2 balanced groups and kept in separate paddocks at a stocking rate of one animal per 8 ha. one group received regular acaricide treatment to control bont (amblyomma hebraeum) and other ticks. the other group was left untreated. the cows were artificially inseminated. ...19957502343
comparison of characteristics of life cycle in female ticks collected on n'dama and zebu cattle.characteristics of the life cycle of female ticks (amblyomma variegatum, hyalomma truncatum and boophilus geigyi) fed on n'dama and zebu cattle were studied in the laboratory from pre-oviposition period to larval development. percentage of a. variegatum eggs hatched and engorgement weight of h. truncatum were lower in ticks collected on n'dama than on zebu cattle. laboratory results confirmed field observations of species specific tick resistance in the n'dama breed.19957502345
evidence of common and genus-specific epitopes on ornithodoros spp. tick (acari: argasidae) salivary zealand white rabbits were repeatedly infested with ornithodoros turicata (duges), ornithodoros talaje (guérin-méneville), and ornithodoros coriaceus (koch) at 2-wk intervals. blood samples were taken from each animal 10 d after each infestation and the titer of anti-tick antibody was determined by enzyme-linked immunosorbent assay. subsequent cross-reactivity studies demonstrated that the antitick antisera nonspecifically bound to salivary gland extract proteins prepared from several other ...19957544412
salivary glands and saliva of amblyomma variegatum ticks: comparison of immatures and adults in relation to the pathogenesis of dermatophilosis.salivary glands from immature and adult amblyomma variegatum were compared for differences in potential components responsible for the systemic aggravation by adult ticks of the skin disease dermatophilosis. whole salivary glands from adult, nymphal and larval a. variegatum ticks were compared for structural differences by light microscopy and for protein content by gel electrophoresis. type-2 salivary gland acini from adult ticks at the second stage of feeding contained significantly greater (p ...19957571338
laboratory reared amblyomma hebraeum and amblyomma variegatum ticks differ in their susceptibility to infection with cowdria ruminantium.the susceptibility of laboratory reared zimbabwean amblyomma hebraeum and a. variegatum ticks to infection with geographically distinct cowdria ruminantium strains was investigated by feeding both species simultaneously on individual sheep infected with one of the four strains (crystal springs [zimbabwe], ball 3 [south africa], gardel [guadeloupe] and nigeria [nigeria]). a. hebraeum ticks demonstrated a high susceptibility to infection with all four c. ruminantium strains. in comparison, a. vari ...19957589273
vector situation of tick-borne diseases in the caribbean islands.the most important ticks transmitting diseases to ruminants in the caribbean islands are: amblyomma variegatum, vector of cowdriosis and associated with acute dermatophilosis; amblyomma cajennense, potential vector of cowdriosis; boophilus microplus, vector of babesiosis and anaplasmosis. at the present time, amblyomma variegatum is widespread in the lesser antilles from barbados to puerto rico. the intensity of the tick control program varies in the different islands and the tick infestation in ...19957597781
review of the molecular biology of cowdria ruminantium.cowdria ruminantium is a rickettsial agent which causes heartwater, an economically important disease of livestock in the tropics and the caribbean. significant advances have been made in the molecular biology of c. ruminantium since its reproducible propagation in vitro in bovine endothelial cells. these advances have been targeted towards the development of improved vaccines and diagnostic tests. several immunogenic proteins of c. ruminantium have been identified and monoclonal antibodies have ...19957597792
seasonal abundance of the tortoise tick amblyomma marmoreum (acari: ixodidae) on the leopard tortoise, geochelone paradalis.a survey of amblyomma marmoreum koch ticks recorded from the leopard tortoise, geochelone paradalis bell, in the national zoological gardens, pretoria, south africa, was carried out over a 19-mo period. no significant differences were found between the tick burdens on male and female tortoises. a. marmoreum showed a clear seasonal pattern of abundance. larvae were present on the tortoise host during late summer, with a peak in february and march; nymphs were abundant during winter, with a peak i ...19957608922
activity of repellents applied to skin for protection against amblyomma americanum and ixodes scapularis ticks (acari: ixodidae).twenty-nine repellents were tested on human skin for duration of activity as protectants against nymphal lone star ticks (amblyomma americanum) and against black-legged or deer ticks (ixodes scapularis say). eleven of these repellents, including deet, provided > 2 h of protection against the lone star tick. one repellent, 1-(3-cyclohexenyl-ylcarbonyl) piperidine, was effective > or = 4 h. four repellents (2 pyridines and 2 piperidines with protection lasting 2.3-3 h) showed acaricidal activity t ...19957616181
review of the ixodid tick fauna (acari: ixodidae) of vietnam.forty-eight species making up the tick fauna of vietnam (genera ixodes, ixodes, amblyomma, aponomma, haemaphysalis, dermacentor, hyalomma, nosomma, rhipicephalus, boophilus) are reviewed, including one genus and nine species that are new records for vietnam, as well as four species described by the author.19957616517
experimental transmission of ehrlichia chaffeensis (rickettsiales: ehrlichieae) among white-tailed deer by amblyomma americanum (acari: ixodidae).ehrlichia chaffeensis anderson, dawson & wilson, causative agent of human (predominantly monocytic) ehrlichiosis, was successfully transmitted experimentally by amblyomma americanum (l.) to white-tailed deer, odocoileus virginianus (zimmerman). deer were needle-exposed intravenously to e. chaffeensis in tissue-culture canine macrophage (dh82) cells, and 11 d later were exposed to laboratory-reared a. americanum larvae, nymphs, and adults for acquisition feeding. three months after this feeding, ...19957616529
ehrlichiosis in a golf-oriented retirement community.ehrlichiosis due to ehrlichia chaffeensis usually occurs sporadically or in small clusters, with an annual incidence estimated at 3 to 5 cases per 100,000 population in areas of endemic disease. the putative principal vector is the lone star tick (amblyomma americanum). we investigated an outbreak of ehrlichiosis that occurred in june 1993 among members of a golf-oriented retirement community (community a) in tennessee. the community is densely wooded and borders a wildlife-management area where ...19957616991
epidemiologic and diagnostic studies of patients with suspected early lyme disease, missouri, 1990-1993.a retrospective case-control study investigated 45 missouri outpatients with annular rashes meeting a surveillance case definition for erythema migrans and with onset in 1990-1991. risk factors included being male, living near a body of water, and hunting. twenty patients (44%) associated their rash with the bite of a tick; of these, 5 described an adult amblyomma americanum. a typical rash was described as expanding over time and measuring 8 cm in diameter at 4 days after onset. mild constituti ...19957622891
biosynthesis of salivary prostaglandins in the lone star tick, amblyomma americanum.dopamine-induced saliva from ticks fed [3h]arachidonic acid contained the radiolabelled prostaglandins e2, f2 alpha, d2, and b2, the latter probably derived from pge2 owing to the alkalinity of tick saliva. prostaglandin synthetase (pgs) activity in the salivary gland homogenate from the lone star tick, amblyomma americanum, could not be detected by standard radiometric methodologies successfully employed for tissues from many animal species, including numerous arthropods. modifications to the a ...19957627205
correlation between antibodies to cowdria ruminantium (rickettsiales) in cattle and the distribution of amblyomma vector ticks in zimbabwe.cowdriosis, caused by cowdria ruminantium, is transmitted by amblyomma ticks, which are widely distributed in zimbabwe. to assess the distribution of this disease in zimbabwe, cattle either exposed to amblyomma ticks or maintained in areas free from these ticks were tested for antibodies to cowdria. a total of 324 sera were tested using competitive elisa and the indirect fluorescent antibody test (ifat). at diptanks in amblyomma-infested areas 52% (n = 95) and 26% (n = 47) of sera were positive ...19937628226
pathogenicity of 17 isolates of entomophagous nematodes (steinernematidae and heterorhabditidae) for the ticks amblyomma variegatum (fabricius), boophilus microplus (canestrini) and boophilus annulatus (say).entomopathogenous nematodes are well known biocontrol agents of insects. they live in the superficial layer of the soil, a location where ticks accomplish their molt and where they oviposit their eggs, making them, theoretically, the preys of infective larvae of nematodes. seventeen strains of entomopathogenous nematodes: eight strains of steinernema and nine strains of heterorhabditis were placed in contact with each of the free living stages of three tick species: amblyomma variegatum, boophil ...19937628227
evaluating the economic damage threshold for bont tick (amblyomma hebraeum) control in zimbabwe.controlling ticks and tick-borne diseases by frequent applications of acaricides (e.g., dipping) is costly, and can leave treated livestock vulnerable to epizootics of tick-borne diseases should the system of applying acaricides break down. the concept of only applying acaricides on an infrequent (strategic) basis often relies on the target tick population displaying a seasonal cycle. however, as adult bont tick (amblyomma hebraeum) infestations in zimbabwe's lowveld do not have a strictly seaso ...19937628230
the effect of inflammatory and hypersensitive reactions, in response to the feeding of the tick amblyomma variegatum, on the progression of experimental dermatophilosis infections.initial infestations of amblyomma variegatum larvae and nymphs, on rabbits and sheep respectively, produced inflammatory reactions in the host's skin; repeated infestations resulted in an increase in development of delayed type hypersensitive reactions. dermatophilus congolensis cocci were applied in titrated doses to hosts at sites of inflammatory or hypersensitive reactions to ticks, and to control hosts with no exposure to ticks. we assessed the resulting infections for three weeks and found ...19937628231
the local effect of hypersensitive or inflammatory reactions to nymphal amblyomma variegatum on simultaneous infections with dermatophilus congolensis.amblyomma variegatum nymphs were applied to sites infected with dermatophilus congolensis on eight rabbits. four rabbits were previously sensitized to the feeding of nymphal a. variegatum to produce hypersensitive reactions to the tick feeding; the remaining four rabbits had no previous exposure to nymphal a. variegatum and produced inflammatory reactions to the tick feeding. the resulting dermatophilosis infections were assessed for three weeks and there was a correlation between the position o ...19937628235
pheromonal composition of two species of african amblyomma ticks: similarities, differences and possible species specific components.two species of bont ticks, amblyomma hebraeum and amblyomma variegatum, common to africa were studied to compare types and quantities of compounds known or believed to serve as components of the attraction-aggregation-attachment pheromone (aaap). a complex of attraction, aggregation and attachment stimulating pheromone components are used by these ticks to detect hosts, mates and, perhaps, minimize interspecific breeding. solvent extraction of pheromone emitting ticks followed by gas chromatogra ...19947628240
factors affecting the distributions of the ticks amblyomma hebraeum and a. variegatum in zimbabwe: implications of reduced acaricide usage.the ticks amblyomma hebraeum and a. variegatum are the main vectors of heartwater, a disease of ruminants caused by cowdria ruminantium, in the agricultural areas of zimbabwe. at present, a. hebraeum is widely distributed in the dry southern lowveld, and occurs in at least seven foci in the higher rainfall highveld. amblyomma variegatum occurs in the zambezi valley and surrounding dry lowveld areas in the northwest. the distribution of a. hebraeum has changed considerably over the past 70 years, ...19947628253
the effect of rainfall on tick challenge at kyle recreational park, zimbabwe.the effect of rainfall pattern on tick challenge was investigated at kyle recreational park, zimbabwe, from 1991 to 1992 using drag and removal plot methods to sample environmental tick density. the abundance of adults and nymphs of the brown ear-tick rhipicephalus appendiculatus and larvae of the bont tick amblyomma hebraeum was positively correlated with monthly rainfall, whereas no relationship with rainfall was revealed for larval r. appendiculatus, adults of the red-legged tick r. evertsi, ...19947628257
reproductive interactions between two australian reptile tick south australia the two tick species amblyomma limbatum and aponomma hydrosauri share the same common reptile host species, but have allopatric distributions which abut along a narrow parapatric boundary. reproductive interference is a mechanism that has previously been suggested could contribute to maintaining the boundary. populations of each species were established in pens within the range of aponomma hydrosauri. pens held either each species alone, or the two species together. the perfor ...19947628259
an investigation into the health status and diseases of wild dogs (lycaon pictus) in the kruger national park.many factors have been cited as possible reasons for the decline in the number of wild dogs (lycaon pictus), but few studies have provided supportive data. between 1990 and 1993, the dynamics of 10 wild dog packs in the southern district of the kruger national park in south africa were monitored. casual observations of the causes of disease and mortality in the entire population were also recorded. during the same period, 46 wild dogs were immobilised, weighed, and subjected to physical examinat ...19957629782
experimental trypanosoma congolense infection on naturally occurring ticks in n'dama and gobra zebu cattle.the effects of experimental trypanosoma congolense infection in gambian n'dama and gobra zebu cattle on number of naturally-occurring adult ticks attaching were studied. an indirect fluorescent antibody test was performed to detect serological prevalence of cowdria ruminantium antibody. the intravenously imposed trypanosome infection did not result in significant (p > 0.05) differences in amblyomma variegatum and hyalomma spp. infestations between control and infected n'dama cattle. control n'da ...19947638002
host-seeking behaviour by australian ticks (acari: ixodidae) with differing host specificities.ticks generally detach from their hosts into sites where they are later exposed to host species which may or may not be suitable for infestation. the question of how four species of ixodid ticks, with differing specificities, behave towards such potential host species was examined. observations of the generalists, aponomma hydrosauri and amblyomma limbatum and the specialists, aponomma fimbriatum and aponomma concolor, showed that the generalists were attracted to a wider range of potential host ...19957641569
evaluation of ixodes scapularis, amblyomma americanum, and dermacentor variabilis (acari: ixodidae) from georgia as vectors of a florida strain of the lyme disease spirochete, borrelia burgdorferi.the ability of three common tick species from georgia to maintain and transmit the causative agent of lyme disease, borrelia burgdorferi, was compared under laboratory conditions. a b. burgdorferi cotton rat isolate (mi-6) from florida was selected as a strain from the south, and the sh2-82 isolate from new york was used as a positive control. amblyomma americanum (l.) and dermacentor variabilis (say) did not transmit the mi-6 isolate from inoculated hamsters to naive laboratory mice, and nympha ...19957650697
lower temperature limits for activity of several ixodid ticks (acari: ixodidae): effects of body size and rate of temperature change.uncoordinated activity threshold temperature, the temperature below which ticks can no longer seek a host in a coordinated manner, and the activity threshold temperature, when all activity ceases, were examined for three species of ticks found in coastal sections of new york. the mean uncoordinated activity threshold and activity threshold temperatures were determined for nymphal, female and male ixodes scapularis say, nymphal, female, and male amblyomma americanum (l.), and for female and male ...19957650705
susceptibility to different tick genera in gambian n'dama and gobra zebu cattle exposed to naturally occurring tick infestations.tick collection on one side of the body and whole tail was performed weekly over one year on 11 gambian n'dama (bos taurus) and 11 gobra zebu (bos indicus) cattle to assess breed susceptibility to naturally occurring ticks. enzyme-linked immunosorbant assay was also performed to assess the serological prevalence of anaplasma marginale antigen and babesia bigemina antibody. packed red cell volume was measured and liveweight gain was recorded. significantly higher numbers of amblyomma variegatum ( ...19957652946
regulation of free arachidonic acid levels in isolated salivary glands from the lone star tick: a role for important regulatory step for prostaglandin synthesis is the availability of the precursor, free arachidonic acid (aa). in isolated salivary glands of the lone star tick, amblyomma americanum (l.), the level of free aa appears to depend on higher phospholipase a2 (pla2) activity rather than decreased rates of re-esterification by lysophosphatide acyl transferase (lat). this conclusion is supported by experiments where inhibition of lat with merthiolate was without effect, while the calcium io ...19957655056
immunoglobulin-g binding proteins in the ixodid ticks, rhipicephalus appendiculatus, amblyomma variegatum and ixodes hexagonus.a guinea-pig immunoglobulin-g linked agarose column was used to detect the immunoglobulin-g binding proteins (igbp) in the ixodid ticks, rhipicephalus appendiculatus, amblyomma variegatum and ixodes hexagonus. igbps were found in salivary gland extract (sge) of the unfed ticks of all 3 species. the sizes of the igbps, as determined by sds-polyacrylamide gel electrophoresis, differed between species. in r. appendiculatus 2 igbp bands were detected in haemolymph collected from unfed females and ma ...19957675530
epidemiological aspects of equine babesioses in a herd of horses in brazil.epidemiological studies of babesia equi and b. caballi were undertaken in a herd of 120 pastured horses in rio de janeiro, brazil. the area where the horses were held was shown to be highly endemic for both babesia spp., i.e. the prevalence of b. equi antibodies in horses aged 6 months or older ranged from 90.6% to 100% as determined by the immunofluorescence antibody (ifa) test, and the prevalence of b. caballi antibodies as determined by western blot ranged from 59.4% to 65.5%. from the herd, ...19957676590
borrelia burgdorferi in eastern virginia: comparison between a coastal and inland virginia, borrelia burgdorferi was more prevalent in a site along the atlantic ocean, near maryland, than in an inland site near williamsburg and yorktown. at the coastal site on assateague island, b. burgdorferi was isolated from 4.2% of 475 animals sampled, including four species of small mammals. serologic tests indicated that 25-37% of the small rodents assayed had been exposed to b. burgdorferi. immunofluorescence antibody assays specific for b. burgdorferi showed spirochete infection in ...19957677212
development and evaluation of pcr assay for detection of low levels of cowdria ruminantium infection in amblyomma ticks not detected by dna probe.the sensitivities of a pcr assay and a dna probe assay were compared for the detection of cowdria ruminantium in amblyomma ticks that were fed on c. ruminantium-infected, clinically reacting, and recovered carrier animals. the pcr assay and dna probe detected infection in 86.0 and 37.0%, respectively, of 100 ticks fed on a febrile animal. in 75 ticks fed on carrier animals, pcr and the dna probe detected infection in 28.0 and 1.33% of ticks, respectively. this demonstrates that the dna probe has ...19957699036
ticks and control methods.ticks are the most important ectoparasites of livestock in tropical and sub-tropical areas, and are responsible for severe economic losses both through the direct effects of blood sucking and indirectly as vectors of pathogens and toxins. feeding by large numbers of ticks causes reduction in live weight gain and anaemia among domestic animals, while tick bites also reduce the quality of hides. however, the major losses caused by ticks are due to the ability to transmit protozoan, rickettsial and ...19947711310
origin of arachidonic acid in the salivary glands of the lone star tick, amblyomma, americanum.the contribution of synthesis and dietary sequestration to the high arachidonate content of the lone star tick, amblyomma americanum, salivary glands was investigated by assessing the salivary metabolites of various radiolabeled fatty acid substrates administered to partially fed females. a portion of each of the fatty acids studied was incorporated into the fatty acid moiety of the phospholipid fraction. [14c]acetate was metabolized only into myristic, palmitic, palmitoleic, steric, and oleic a ...19957711753
[changes in the bactericidal activity of the cementing fraction in ixodid tick saliva under the influence of the presence of the tick-borne encephalitis virus].it is demonstrated that the abundance of bactericidal compounds in the salivary cement plug of ixodid ticks is changing under the influence of virulent tick-borne encephalitis virus (tbev) reproduction in their bodies. tbev infected ixodes persulcatus cement plug-forming lytic zone size enlarged in comparison with the naive tick one whereas micrococcus lysodeikticus lytic zones induced by the cement plug of tbev infected amblyomma hebraeum nymphs or rhipicephalus appendiculatus females reduced c ...19947715548
physiological responses of beef cattle to gulf coast tick (acari: ixodidae) infestations.nine yearling crossbred beef steers, bos taurus l., were used to examine physiological responses to gulf coast tick, amblyomma maculatum koch, infestation. steers were stanchioned indoors in individual environmentally controlled rooms. on day 0, each animal received 0, 25, or 75 pairs of ticks. physiological variables measured daily were feed intake, heart rates, rectal temperatures, and respiration rates. blood samples were collected from each animal on days 7, 21, and 42 for serum constituent ...19957722083
uptake, incorporation and redistribution of arachidonic acid in isolated salivary glands of the lone star tick.the ability of isolated salivary glands from the lone star tick, amblyomma americanum, to take up, incorporate and redistribute [3h]arachidonic acid was examined. uptake of arachidonic acid was concentration dependent--a single salivary gland incorporated up to approximately 2.8 micrograms arachidonic acid in 60 min. over 90% of the [3h]arachidonate entering the glands was esterified and found only in the phospholipid (approximately 80%) and triglyceride (approximately 10%). essentially no radio ...19957742831
detection of rickettsia japonica in haemaphysalis longicornis ticks by restriction fragment length polymorphism of pcr product.pcr was applied to the detection of rickettsia japonica, the causative agent of oriental spotted fever (osf), in ticks collected at two sites of the muroto area on shikoku island, a major area in japan where osf is endemic. primer pair rr190.70p and rr190.602n of the r. rickettsii 190-kda antigen gene sequence of regnery and others (r.l. regnery, c.l. spruill, and b.d. plikaytis, j. bacteriol. 173:1576-1589, 1991) primed the dna extracted from haemaphysalis longicornis ticks but not those extrac ...19957790445
ectoparasites of opossums and raccoons in southeastern georgia.twelve species of ectoparasites (four fleas, three ticks, three chiggers, one macronyssid mite, and one atopomelid mite) were recovered from 42 opossums, didelphis virginiana kerr, live-trapped from september 1992 through april 1994 in southeastern georgia. the fleas, ctenocephalides felis (bouché) (prevalence = 19%) and polygenis gwyni (c. fox) (36%); the ticks, dermacentor variabilis (say) (40%) and ixodes scapularis say (19%); and the macronyssid mite, ornithonyssus wernecki (fonseca) (21%), ...19947815408
notes on the biology of amblyomma dissimile koch, 1844 (acari:ixodida) on bufo marinus (linnaeus, 1758) from brazil.amblyomma dissimile is a common ectoparasite of cold blooded animals and is an accidental ectoparasite of some wild mammals. details of the biology of specimens from the state of amapá were studied in the laboratory in a humidity chamber at an average environmental temperature of 19.5 degrees c, using bufo marinus as host for the time in brazil. we also report the first record of this species in the state of minas gerais.19947823816
seasonal variation of ticks (ixodidae) in bos taurus x bos indicus cattle under rotational grazing in forested and deforested habitats in northwestern argentina.the seasonal occurrence of ticks infesting cattle was monitored in a bos taurus x bos indicus commercial herd fed on a combination of native grasses and annual pastures in northwestern argentina. the number of female ticks (boophilus and amblyomma) and the proportion of cattle infested with larvae and nymphs of amblyomma ticks were recorded from a sample of 15 cows in 24 visits at intervals of 21-50 days from 5 december 1986 to 24 november 1988. the cattle were maintained on native grasses in fo ...19947839563
rearing amblyomma variegatum ticks in the laboratory: a simple technique to enhance attachment. 19947841497
ecdysteroid titre and metabolism and cuticle deposition during embryogenesis of the ixodid tick amblyomma hebraeum (koch).three embryonic cuticles are formed before larval cuticle deposition during embryonic development of amblyomma hebraeum. the quantity of radioimmunoassay-positive material varied between 50 and 200 pg ecdysone equivalents per mg, but no significant peaks were detected. maternally incorporated [3h]-20-hydroxyecdysone and [3h]-ecdysone contained in freshly laid eggs appear to be conjugated to c-22 fatty acid esters and 3 alpha epimers of those esters, and, thus, appear doubly inactivated. in addit ...19957858939
seasonal prevalence of ticks and their association with dermatophilosis in cattle on the accra plains of ghana.the seasonal abundance of adult ticks on cattle and their association with dermatophilosis were investigated in five herds on the coastal plains of ghana over a 26-month period. four genera, amblyomma, boophilus, rhipicephalus and hyalomma were identified, a. variegatum being the predominant species occurring throughout the year with two peaks of infestation, one in april-may and the other in november. a significant positive correlation was revealed between a. variegatum and dermatophilosis in f ...19947863064
using cuticular hydrocarbon composition to elucidate phylogenies in tick populations (acari: ixodidae).cuticular hydrocarbon composition is used to explain hypothetical phylogenies among sympatric and allopatric populations of amblyomma cajennense, a. variegatum and ixodes ricinus tick species. the method proposed here uses a parsimony analysis of endemicity by disjunct biochemical data (paedb) based in the pattern of cuticular hydrocarbons. the advantage of our approach is that information contained in fragments that are not conserved in all the individuals of a populations need not be discarded ...19947863854
cytosystematics of five north american amblyomma (acarina: ixodidae) species.the karyotypes of 5 species of amblyomma ticks found in north america were examined for the presence and location of constitutive heterochromatin (c-bands). all specimens examined had 20 autosomes and an xx:xo sex-determining system, with the x being the largest element in the karyotype. except as noted in text, the autosomes of all species were acrocentric and heterochromatin was restricted to the centromeric region. the third largest autosome in 4 of the 5 species displayed a consistent band o ...19957876973
lymphocyte proliferative responses and the occurrence of dermatophilosis in cattle naturally infested with amblyomma variegatum.the proliferative response of lymphocytes from tick-infested zebu type, n'dama and friesian cattle and acaricide-treated zebu types and friesians in concanavalin a (con a) stimulated cultures was monitored regularly for periods ranging from 11 to 27 months. the numbers of ticks on the animals and the presence of dermatophilosis were also noted. the friesian cattle carried most and the n'dama fewest amblyomma variegatum ticks. the tick-infested friesians all developed severe clinical dermatophilo ...19947879382
helminth and arthropod parasites of indigenous goats in the northern transvaal.helminth and arthropod parasites of 60 female indigenous goats of three age groups on a farm in the northern transvaal were collected, identified and counted. anoplocephalid tapeworms were present in the two younger groups of goats, while larvae of taenia hydatigena were recovered from all three groups. eight species and two genera of nematodes were found in the youngest goats, five species and three genera in the middle group and six species and two genera in the oldest goats. strongyloides pap ...19947898893
patterns of cuticular hydrocarbon variation and genetic similarity between natural populations of amblyomma cajennense (acari: ixodidae).gas chromatography has been used to analyze the variation in cuticular hydrocarbon patterns between several populations of amblyomma cajennense. 88 compounds were detected and these could be divided into 17 groups of hydrocarbons. heterozygosis in the populations ranges from 0% to 25.84%. isomers for pentacosane, heptacosane and nonatriacontane are the most variable, with 13, 10 and 11 variants, respectively. nei's genetic identity and genetic distance show that populations may be considered as ...19937903139
identification of rickettsiae from ticks collected in the central african republic using the polymerase chain reaction.spotted fever rickettsiosis have been identified on the african continent since their historical description in 1909. however, only rickettsia conorii and r. africae have been described in africa, and the current techniques for the detection of rickettsiae in ticks are difficult to apply in large field studies. we report here a preliminary study using genomic amplification by the polymerase chain reaction followed by restriction fragment length polymorphism (pcr-rflp) analysis directly on 310 cr ...19947908504
a new pathogenic spotted fever group rickettsia from africa.a spotted fever group (sfg) rickettsia was isolated in zimbabwe from a patient with tick-bite, fever, headache and regional lymphadenopathy. a further six isolates were obtained from amblyomma hebraeum ticks collected in zimbabwe. these human and tick isolates were indistinguishable from each other, and from an ethiopian sfg rickettsia, by microimmunofluorescence (mif), sodium dodecyl sulphate-polyacrylamide gel electrophoresis (sds-page), western blotting and polymerase chain reaction followed ...19947911846
isotopes as host blood markers to measure blood intake by feeding ticks (acari: ixodidae).we have modified an experimental technique in which two different isotopes (cr51 and i125) were used simultaneously as blood markers for determining the amount of blood removed by feeding ticks. this method enables us to measure separately and directly the volumes of red blood cells and plasma in ticks and to calculate the ratio between the two parameters (concentrating ability). the concentration of red blood cells in nymphs of amblyomma hebraeum kock and rhipicephalus appendiculatus neumann an ...19947932595
cuticular hydrocarbon composition, phenotypic variability, and geographic relationships in allopatric populations of amblyomma variegatum (acari: ixodidae) from africa and the caribbean.gas chromatography of cuticular hydrocarbons is used to determine the degree of genetic similarity and heterozygosity among 20 populations of amblyomma variegatum (f.) collected from africa and the caribbean. twenty-one compounds were detected in at least 90% of the specimens studied; another 57 hydrocarbons were detected in a variable number of specimens, ranging from 50 to 90% of all ticks extracted. visual inspection of chromatograms revealed prominent differences in the relative abundance of ...19947932599
integrated management strategies for amblyomma americanum (acari: ixodidae) on pastured beef on tick control and knowledge of the damage caused to beef cattle by tick feeding were incorporated into a computerized dynamic life table model (lstsim) for amblyomma americanum (l.). simulations were made to determine economically feasible, 5-yr integrated pest management (ipm) strategies for a. americanum in forage areas utilized by bos taurus, bos indicus, and crossbred cattle (b. taurus x b. indicus). the effects of host resistance, pasture rotation, habitat conversion, topical acarici ...19947932604
evidence supporting the presence of borrelia burgdorferi in missouri.although lyme disease is commonly seen in the southcentral united states, the epidemiology of the disease is poorly defined there. the purpose of this study was to document the presence of borrelia burgdorferi in ticks collected in southeastern missouri and around the city of st. louis. spirochetes were detected and identified as b. burgdorferi by immunofluorescent antibody (ifa) tests using the monoclonal antibody h5332 in 1.9% of amblyomma americanum and 2.0% of dermacentor variabilis ticks co ...19947943575
parasites of domestic and wild animals in south africa. xxxii. ixodid ticks on scrub hares in the transvaal.a total of 264 scrub hares (lepus saxatilis) were examined for ixodid ticks at various localities in the kruger national park, eastern transvaal lowveld. thirteen tick species were recovered from these hares. the seasonal abundances of the immature stages of amblyomma hebraeum, amblyomma marmoreum, hyalomma truncatum, rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, rhipicephalus simus and rhipicephalus zambeziensis and all stages of a rhipicephalus sp. (near r. pravus) were determin ...19937970571
isolation and preliminary characterisation of a previously unidentified theileria parasite of cattle in kenya.a theileria parasite was isolated from cattle on a ranch in kenya where it caused mild theileriosis in approximately one third of the cattle exposed to natural tick challenge. the parasite was isolated by inoculation of blood into two experimental cattle. blood from one of these cattle was used to infect two splenectomised cattle which developed high piroplasm parasitaemias and severe anaemia. a blood stabilate was prepared from one of the splenectomised cattle and produced high parasitaemias in ...19947973080
[ticks and hemoparasitoses of livestock in senegal. vi. the soudano-sahelian zone].the authors report the results of a study on ticks and hemoparasitoses among cattle, sheep and goats in the sudano-sahelian zone. during a period of 15 months, ticks were systematically removed from 40 cattle, 40 sheep and 40 goats in order to assess the population dynamics and determine more accurately the preferential sites of settlement of the different species. the following species were collected in ruminants: hyalomma truncatum, h. marginatum rufipes, rhipicephalus evertsi evertsi, rh. gui ...19947991897
[crimean-congo hemorrhagic fever in senegal. latest data on the ecology of the cchf virus].the authors finalize the knowledge on the ecology of the cchf virus in senegal, west africa. they specify two new major data for the understanding of the viral ecology in west africa. the recognition of a bird species, common and widely distributed in senegal (tockus erythrorhynchus, coraciiformes, bucerotidae), that replicates the virus and infects the immature stages of its current parasite hyalomma marginatum rufipes in more than 90% of the cases, explains why the minimum infection rate of th ...19948003897
control of tsetse flies in uganda by dipping cattle in deltamethrin.the effect of treating cattle with deltamethrin to control tsetse flies and ticks was investigated on 2 ranches 8 km apart in central uganda where there is a high risk of trypanosomosis. this area had a moderate challenge of glossina pallidipes. the cattle had very low challenge of rhipicephalus appendiculatus, amblyomma variegatum, boophilus decolaratus and rhipicephalus evertsi evertsi, due to regular treatment with dioxathion. on one ranch a dip was charged with deltamethrin to treat cattle r ...19948009646
effect of acaricide control of amblyomma variegatum ticks on bovine dermatophilosis on nevis.a sentinel group of 8 bos taurus cattle was compared with similar cattle in a herd of 90 of which 21 were pastured with the sentinels. the sentinel group was not treated with acaricide whilst the rest of the cattle were treated weekly with the organophosphate acaricide ethion. weekly counts of adult ticks and rankings of dermatophilosis were made on the sentinel herd. the remaining cattle were observed for the presence of ticks and dermatophilosis prior to the weekly treatment with acaricide. al ...19948009647
influence of environmental factors on oviposition and egg development in amblyomma limbatum and aponomma hydrosauri (acari: ixodidae).this study examined the influence of temperature and light on the length of the pre-oviposition period of engorged females of two australian ixodid ticks, amblyomma limbatum and aponomma hydrosauri. the hatching success and development time of eggs of both species were also compared at different temperatures and relative humidities. darkness was found to have no effect on the duration of the pre-oviposition time or reproductive output of females of either species. in contrast, the preoviposition ...19948021110
effect of acaricide treatment of cattle on amblyomma variegatum (acari: ixodidae) infestation of mongooses (carnivora: viverridae: herpestes auropunctatus) in guadeloupe, french west indies.the effect of acaricide treatment of cattle on the infestation of the small indian mongoose (herpestes auropunctatus hodgson) by amblyomma variegatum (f.) was determined during a field evaluation of selected acaricides in guadeloupe, french west indies. from april 1990 to april 1991, cattle at one site were treated every 14 d with pour-on formulations of deltamethrin, flumethrin, or permethrin; and cattle at a second site were treated as per a local standard treatment using a spray formulation o ...19948057326
ticks (acari: ixodidae) collected from small and medium-sized kansas species of hard-bodied ticks were collected from 20 species of small and medium-sized mammals in kansas; amblyomma americanum l., dermacentor variabilis (say), haemaphysalis leporispalustris (packard), ixodes cookei packard, i. kingi bishopp, i. sculptus neumann, and i. texanus banks. dermacentor variabilis was found statewide, a. americanum only in the eastern one-third of the state, and the ixodes spp. and h. leporispalustris were widely scattered. the most common tick found was d. varia ...19948057327
ticks (acarina: ixodidae) of reptiles from central, lusaka and southern provinces of zambia.during the period 1988-1991, reptiles (23 snakes, 36 tortoises, 25 chameleons and 2 monitor lizards) from central, lusaka and southern provinces of zambia were caught and checked for ticks. only 2 snakes, respectively one python sebae (gmelin, 1789) and one bitis arietans (merrem, 1820), 8 tortoises, respectively seven geochelone pardalis (bell, 1828) and one kinixys belliana (gray, 1831) were found infested with a small number of ticks: nymphs and adults of aponomma latum (koch, 1844) and ambly ...19938065818
genome size and organization in the ixodid tick amblyomma americanum (l.).we used dna reassociation kinetics to determine genome size and organization in the ixodid tick amblyomma americanum. we calculated the genome size of a. americanum to be approximately 1.08 pg or 1.04 x 10(9) base pairs and to consist of 35.8% unique dna, 4.2% foldback sequences, 17.9% highly repetitive sequences, and 42.1% moderately repetitive sequences. comparison of the reassociation kinetics of long and short fragments revealed repetitive sequences to be distributed in a pattern of long per ...19948069417
[ticks and hemoparasitoses in livestock in senegal. v. the northern guinea area].the authors report the results of a study on ticks and hemoparasitoses among cattle, sheep and goats in the north-guinean zone. during a period of 15 months, ticks were systematically removed from 40 cattle, 40 sheep and 40 goats in order to assess the population dynamics and to determine more accurately the preferential sites of settlement of the following different species collected from these animals: amblyomma variegatum, boophilus geigyi, hyalomma truncatum, h. marginatum rufipes, rhipiceph ...19938073170
cross-reactivity between hard tick antigens.1. the present study was carried out to determine the target cells and tissues for anti-tick immunoglobulins using an indirect immunohistochemical technique. 2. sections in triplicate prepared from unfed ticks rhipicephalus appendiculatus, r. evertsi and amblyomma variegatum were used to assess the cross-reactivity of serum from guinea pigs naturally infested with these tick species or immunized against them. 3. the sections showed slight (+) to strong ( +) labelling of several structures in the ...19948081294
host resistance to ticks (acari: ixodidae) in different breeds of cattle at bako, ethiopia.european cattle breeds are being introduced into ethiopia in an effort to improve the productivity of indigenous breeds. the ethiopian cattle breeds horro and boran were compared for tick burdens with their crosses with friesian, jersey and simmental. horro animals had the lowest tick burdens and the horro x friesian the highest. adaptation to their environment and long-term natural selection for tick resistance in horro cattle is the most likely explanation. repeatability of tick burdens in all ...19938109054
the significance of recent highlights in heartwater research.many of the objectives identified earlier, with regard to research on cowdriosis, have been achieved during the past decade. some contributions such as the development of cowdria specific dna probes and the attenuation of the organisms are still in the experimental stage but others, such as in vitro cultivation, are already well established practices in many laboratories. serological techniques are now more widely used since other methods and other sources of antigen became available. however, p ...19938134619
the relationship between cowdria and ehrlichia: change in the behaviour of ehrlichial agents passaged through amblyomma hebraeum.following an earlier report that an ehrlichia-like agent isolated from an adult hyalomma truncatum female became more pathogenic and elicited a disease in sheep indistinguishable from heartwater after having been passaged through amblyomma hebraeum, a similar phenomenon is herewith recorded. an ehrlichial agent demonstrated in the blood smear of a serologically positive, naturally infected lamb, changed in behaviour and assumed the characteristics of cowdria after passage through a. hebraeum. cr ...19938134623
seroconversion to cowdria ruminantium of malawi zebu calves, reared under different tick control strategies.the seroconversion by indirect elisa to cowdria ruminantium over the first year of life of sixty-six malawi zebu calves born into groups which were dipped 17 times per year was compared to seroconversion of 32 calves born into non-dipped groups. amblyomma variegatum tick counts and clinical disease in each group of cattle were monitored throughout the study period. no cases of heartwater were seen in either group of calves over the first 22 months of life. only one case of heartwater was observe ...19938134628
cowdria ruminantium identified in amblyomma gemma using a dna probe pcs20.amblyomma gemma ticks were collected from wild animals on a 20,000 acre game ranch in a heartwater endemic area in kenya, close to nairobi. a. variegatum is the main vector of heartwater in kenya. e.a. lewis, 1947, in a one sentence report has implicated a. gemma to be a vector of heartwater without giving any details. adult a. gemma were collected from giraffe giraffa camelopardalis, hartebeest alcephalus busephalus, eland taurotragus oryx and ostrich struthio camelus during cropping exercises. ...19938134629
development and transmission of cowdria ruminantium by amblyomma males transferred from infected to susceptible sheep.male amblyomma sp. were tested as vectors of cowdria ruminantium, causative agent of heartwater disease. the males were allowed to feed on sheep experimentally infected with c. ruminantium and then were transferred to susceptible sheep to test for transmission of the rickettsia. the experiments were done in two trials. in the first trial, a. hebraeum were exposed to the palm river stock of c. ruminantium, while in the second trial the kiswani stock of cowdria was tested with a. variegatum. ticks ...19938134630
cowdriosis in senegal: some epidemiological aspects.the results of a study on the abundance of amblyomma variegatum in different ecological zones and of cowdria ruminantium infection rates in nymphal and adult ticks of the north guinean zones are given. joint research is also conducted on the evaluation of seroprevalence. in this study, it appears that the vector is most important in the north guinean zone, followed by the south sudan and the coastal niayes zones. elsewhere, the tick populations are not significant or absent. the infection rate i ...19938134635
the tick vectors of cowdriosis in angola.amongst the amblyomma species presently known to be capable of transmitting cowdria ruminantium six have been recorded in angola. a. pomposum is the most important and widely distributed. of secondary importance are a. variegatum, which prevails in cabinda and moxico provinces, and a. astrion which occurs in the littoral and transition strips and on camabatela plateau. a. sparsum and a. tholloni which are specific parasites of wild hosts are considered accidental vectors. a. hebraeum was introdu ...19938134639
cellular responses in experimental chronic and acute dermatophilosis infections of sheep.the cellular infiltrate into the dermis in dermatophilosis lesions is composed of a range of cell types. the aim of this study was to establish if the composition of the cellular infiltrate in chronic lesions was different from that in healing lesions. experimental dermatophilus congolensis infections of sheep were used to study the sequential changes in cell types during the course of chronic and acute infections. infestations of adult amblyomma variegatum ticks were used to produce chronic les ...19938134642
an attempt to correlate cattle breed origins and diseases associated with or transmitted by the tick amblyomma variegatum in the french west using biological data and historical research, we have tried to explain the difference between resistance and susceptibility to the diseases transmitted (cowdriosis) or associated (dermatophilosis) with the tick amblyomma variegatum, in two cattle breeds of the french west indies: the creole crossbred cattle of guadeloupe and the brahman zebu cattle of martinique. have been studied the polymorphisms of 5 independent genetic systems (erythrocytic haemoglobin, serum albumin and transferrin, the ...19938134643
an attempt to identify genetic markers of resistance or susceptibility to dermatophilosis in the zebu brahman population of martinique.dermatophilosis is a disease associated with the tick amblyomma variegatum, and a genetic predisposition to the manifestation of symptoms has been demonstrated. indeed, the creole cattle of guadeloupe constitute a population which is highly resistant to this disease, whereas the brahman zebu cattle of martinique seem very susceptible. however, in this brahman population there is a gradient regarding the severity of symptoms depending on individuals. in several herds of these pure zebu brahman, k ...19938134644
the epidemiology and control of camel dermatophilosis.camel dermatophilosis was only recently described. it appears however that it is more widespread than originally thought. in kenya it has generally been found in the main semi-arid camel rearing areas of samburu and laikipia districts although it has not yet been found in the arid areas of turkana district. in an investigation of ticks on 200 camels, no amblyomma variegatum ticks were found although many other ticks were present. a. variegatum is suspected to transmit dermatophilosis in many dom ...19938134647
the systemic effect of adult and immature amblyomma variegatum ticks on the pathogenesis of dermatophilosis.the systemic effect of adult and nymphal amblyomma variegatum on the pathogenesis of experimental infections of dermatophilus congolensis was investigated. three groups of four sheep were used with all 12 sheep being infected with identical titrated doses of d. congolensis one group of sheep was simultaneously infested with adult a. variegatum the second with nymphal a. variegatum and the third group were the controls, with no exposure to ticks. assessment of the resulting infections indicate th ...19938134648
the effect of tick control on the prevalence of dermatophilosis on indigenous cattle in ghana.the effectiveness of three tick control regimes on the occurrence of amblyomma variegatum and dermatophilosis on cattle on the coastal plains of ghana were compared. animals at one kraal were sprayed with amitraz at predilection feeding sites of ticks every second week using a high concentration minimum volume technique. animals at two other kraals were treated with a deltamethrin based pour-on acaricide; at one kraal it was applied once every month while at the other kraal it was used at strate ...19938134649
ventilation in the adults of amblyomma hebraeum and a. marmoreum (acarina, ixodidae), vectors of heartwater in southern africa.the objective of this study was to establish the major features of respiratory gas exchange in unfed adults of the ticks amblyomma hebraeum and a. marmoreum, both vectors of heartwater in southern africa. carbon dioxide emission of ticks was measured at 25 degrees c using flow-through respirometry in order to determine standard metabolic rate (smr) and the temporal pattern of gaseous emission. for both species, smr was extremely low and approximately 100 fold less than that predicted for an inse ...19938134650
variability of cattle infestation by amblyomma variegatum and its possible utilisation for tick control.a great variability of the individual infestation by amblyomma variegatum adults was observed on naturally infested gudali zebus. some of the animals (called "attractive for a. variegatum") had a tick burden 10 to 16 times higher than that of the least parasitized cattle of the herd (called "non-attractive"). ranking of the animals based on a. variegatum infestation was correlated for successive tick counts. experiments were designed to determine if the "non-attractive" cattle remained lightly i ...19938134651
acaricides for eradication of the tick amblyomma variegatum in the caribbean.the success of an eradication campaign against the tropical bont tick in the caribbean imposes the use of active acaricide compounds, if possible with residual activity, easy to apply and requiring few or no accessible water supplies and expensive application equipment. tests of in vitro susceptibility of tick strains from puerto rico and guadeloupe as well as observations of the impact of the current tick control campaigns conducted in some caribbean islands, seem to indicate that there is no p ...19938134652
eradication of a new focus of amblyomma variegatum in puerto may 1992 an infestation with the tropical bont tick appeared in a small dairy heifer replacement herd in camuy, puerto rico, a completely new site located near puerto rico's northwest coast. this finding occurred after some three years of no infestation in either puerto rico or the u.s. virgin islands and is not suspected of being associated with any previous infestations. the methods used to eradicate this tick include spray treatment at a two-week interval of all domestic livestock, with am ...19938134653
progress towards a program for the eradication of amblyomma variegatum from the caribbean.amblyomma variegatum (fabricius), the tropical bont tick, is now widely distributed in the caribbean. eighteen islands countries are now or were recently infested with the tick. to stop the spread of this tick to other non-infested islands and to the mainland areas of south, central and north america, a regional eradication program has been proposed and endorsed by the respective governments on each of the amblyomma variegatum infested islands, including the french government and caricom member ...19938134654
identification of vertebrate volatiles stimulating olfactory receptors on tarsus i of the tick amblyomma variegatum fabricius (ixodidae). i. receptors within the haller's organ capsule.gas chromatography-coupled electrophysiological recordings (gc-el) from olfactory sensilla within the capsule of haller's organ of the tick amblyomma variegatum indicate the presence of a number of stimulants in rabbit and bovine odours, and in steer skin wash. some of these stimulants were fully identified by gas chromatography-mass spectrometry analysis and by matching electrophysiological activity of synthetic analogues as: 1) hexanal, 2-heptenal, nonanal, furfural, benzaldehyde, and 2-hydrox ...19948151519
[the acquisition of resistance by laboratory mice to amblyomma hebraeum (ixodidae) larvae].repeated feedings of larval amblyomma hebraeum ticks on laboratory mice results in strong decrease of engorged tick yield (from 65-73% after primary feeding to 11% after secondary feeding). laboratory mice differ essentially in this respect from rabbits and sheep which are unable to acquire the resistance (see norval, 1978) to larvae of this tick.19938152843
aponomma (bothriocroton) glebopalma, n. subgen., n. sp., and amblyomma glauerti n. sp. (acari: ixodida: ixodidae), parasites of monitor lizards (varanidae) in australia.aponomma (bothriocroton) glebopalma, n. subgen., n. sp., and amblyomma glauerti, n. sp. (acari: ixodidae), are described from the monitor lizards varanus glebopalma mitchell and varanus glauerti mertens in western australia and the northern territory, australia. the new subgenus is erected to accomodate a. (bothriocroton) glebopalma, a new species with a deeply pitted and pilose scutum in both the adult and immature stages, unlike all other described species of aponomma. this new species is foun ...19948158616
respiratory gas exchange in the tick amblyomma hebraeum (acari: ixodidae).respiratory gas exchange was studied in unfed adult amblyomma hebraeum koch. carbon dioxide emission was measured at 25 degrees c using flow-through respirometry to determine standard metabolic rate and the temporal pattern of gaseous emission. the standard co2 production rate (svco2) of inactive ticks was 0.0135 +/- 0.0085 ml g-1 h-1, and the standard o2 consumption rate (svo2) was 0.0158 +/- 0.0097 ml g-1 h-1. ventilation was discontinuous and was characterized by periodic bursts of co2 emissi ...19948158626
wildlife as hosts for ticks (acari) in antigua, west indies.a survey was conducted to determine the status of wild mammals and birds as hosts for amblyomma variegatum (f.) and other tick species in antigua. surveys of wild mammals and birds were conducted periodically from september 1988 through may 1991. wild mammals surveyed included the small indian mongoose (herpestes auropunctatus hodgson), norway rat (rattus norvegicus berkenhout), and house mouse (mus musculus l.), but only mongooses were surveyed intensively. larvae and nymphs of a. variegatum, l ...19948158630
seasonal and annual abundance of amblyomma americanum (acari: ixodidae) in central georgia.seasonal and annual changes in the abundance of amblyomma americanum (l.) larvae, nymphs, and adults were monitored over a 5-yr period in the piedmont physiographic region of georgia. tick abundance was monitored with cloth drags (all life stages) and co2-baited cloth panels (nymphs and adults) monthly during march through september from 1987 through 1991. larvae appeared in substantial numbers in july and were most numerous in august and september. small numbers of unfed larvae apparently overw ...19948158632
influence of annual and biennial prescribed burning during march on the abundance of amblyomma americanum (acari: ixodidae) in central georgia.a 5-yr study to evaluate the influence of annual and biennial prescribed burning in march on the abundance of amblyomma americanum (l.) was conducted on oconee wildlife management area in the piedmont physiographic region of georgia. tick abundance on plots embedded in larger burned and unburned areas were monitored with cloth drags and co2-baited cloth panels monthly during march through september from 1987 through 1991. annual and biennial prescribed burning from 1988 to 1991 significantly red ...19948158633
epidemiological studies on dermatophilosis in the caribbean.dermatophilosis is one of the most important diseases of domestic ruminants in the caribbean islands where the clinical disease has been shown to be associated with the presence of the tick amblyomma variegatum. seroepidemiological studies were conducted to clarify the epidemiology of the disease in the region with a particular attention paid to the role of a. variegatum. a bank of 1300 cattle sera from the lesser antilles was screened by elisa for the presence of antibodies to dermatophilus con ...19938161379
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