Publications

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%), ...	1994	7815408
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 ...	1995	7790445
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 ...	1995	7742831
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 ...	1995	7722083
[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 ...	1994	7715548
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 ...	1995	7711753
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 ...	1994	7711310
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 ...	1995	7699036
borrelia burgdorferi in eastern virginia: comparison between a coastal and inland locality.	in 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 ...	1995	7677212
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, ...	1995	7676590
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 ...	1995	7675530
regulation of free arachidonic acid levels in isolated salivary glands from the lone star tick: a role for dopamine.	an 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 ...	1995	7655056
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 ( ...	1995	7652946
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 ...	1995	7650705
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 ...	1995	7650697
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 ...	1995	7641569
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 ...	1994	7638002
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 ...	1995	7629782
reproductive interactions between two australian reptile tick species.	in 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 ...	1994	7628259
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, ...	1994	7628257
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, ...	1994	7628253
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 ...	1994	7628240
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 ...	1993	7628235
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 ...	1993	7628231
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 ...	1993	7628230
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 ...	1993	7628227
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 ...	1993	7628226
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 ...	1995	7627205
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 ...	1995	7622891
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 ...	1995	7616991
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, ...	1995	7616529
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.	1995	7616517
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 ...	1995	7616181
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 ...	1995	7608922
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 ...	1995	7597792
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 ...	1995	7597781
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 ...	1995	7589273
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 ...	1995	7571338
evidence of common and genus-specific epitopes on ornithodoros spp. tick (acari: argasidae) salivary proteins.	new 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 ...	1995	7544412
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.	1995	7502345
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. ...	1995	7502343
seasonal incidence and hemoparasite infection rates of ixodid ticks (acari: ixodidae) detached from cattle in costa rica.	to 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 ...	1994	7501871
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 ...	1994	7501358
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 ...	1995	7494060
bacteriocidal qualities of ixodid tick (acarina: ixodidae) salivary cement plugs and their changes under the influence of a viral tick-borne pathogen.	the abundance of bacteriocidal compounds contained in the salivary cement plug of ixodid ticks was changed because of the reproduction of tick-borne encephalitis virus (tbev) in their bodies. the size of tbev-infected ixodes persulcatus shulze lytic zone surrounding the cement plug enlarged to that of naive ticks, whereas micrococcus lysodeikticus (cohn) lytic zones induced by the cement plugs of tbev-infected amblyomma hebraeum koch nymphs or rhipicephalus appendiculatus neumann females were re ...	1995	7473610
ectoparasites collected from bobwhite quail in the southeastern united states.	twenty-one species of ectoparasites representing 19 genera were collected from 481 bobwhite quail (colinus virginianus) from nine areas in four southeastern states. sixteen species, amblyomma americanum, haemaphysalis chordeilis, haemaphysalis leporispalustris, eutrombicula alfreddugesi alfreddugesi, neoschoengastia americana, boydaia colini, pterolichus sp., colinophilus wilsoni, megninia sp., apionacarus wilsoni, colinoptes cubanensis, menacanthus pricei, colinicola numidiana, gonoides ortygis ...	1980	7463603
cattle ticks from the waterberg district of the transvaal.	macroscopically visible ticks were collected from the hides of 28 cattle slaughtered in pairs during a period of 14 months in the waterberg district. in order of prevalence rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, amblyomma hebraeum, hyalomma marginatum rufipes, ixodes cavipalpus, hyalomma truncatum and boophilus decoloratus were recovered. immature stages of the three commonest species constituted a major portion of the population for varying periods during the months april ...	1980	7452655
susceptibility to cholinesterase-inhibiting acaricides of organochlorine-resistant and susceptible strains of amblyomma variegatum (acari: ixodidae) and in organochlorine-susceptible strain of a. lepidum.		1980	7420364
a critical evaluation of the role played by the red-billed oxpecker buphagus erythrorhynchus in the biological control of ticks.	buphagus erythrorhynchus uses 4 feeding methods--scissoring, plucking, pecking and insect catching. during the day the birds spend 68% of their time feeding, with peaks of activity during the early morning and late afternoon. a total of 21 641 ixodid ticks were found in 53 stomachs examined, with a range of between 16 and 1 665 per stomach. boophilus and rhipicephalus were the most important genera eaten. thirty diptera, also found in the stomachs, accounted for 0,4% of the diet by mass. the foo ...	1980	7413164
experimental transmission of african swine fever virus by ornithodoros coriaceus, an argasid tick indigenous to the united states.	three ticks, indigenous to the united states, were assessed for their ability to maintain and transmit african swine fever virus (asfv). amblyomma americanum and a cajennense adults and nymphs maintained virus for 4 to 7 days after engorging on infected swine blood; however, virus was not carried through the subsequent molt of nymphs and it was not transmitted vertically to the eggs and larvae of the infected females. on refeeding of the ticks, infection was not transmitted to healthy swine. orn ...	1980	7406278
epidemiological investigation for arboviruses in jamaica, west indies.	arbovirus investigation in jamaica was undertaken between 1960 and 1975. serological studies showed that antibodies to dengue type virus and st. louis encephalitis virus (sle) were prevalent throughout the island for several years. in urban communities, the incidence of dengue antibody was higher than for sle; however, in children under 10 years of age antibody to both viruses was rarely present. in rural areas, sle was prevalent in adults and children. this virus was isolated fom culex nigripal ...	1980	7406115
regional specialization of the sperm membrane in the tick amblyomma hebraeum koch (acari: ixodidae).	the spermatozoon of amblyomma hebraeum is about 200 micrometers long and comprises: (l)a thick, club-shaped anterior part, about 20 micrometers long bearing at its apex a "tactile" hemisphere, and (2) an elongated tail-like part, about 180 micrometers long. the surface of the "tactile" hemisphere is covered by numerous bulbous expansions, attached to it by short stalks. the base of the hemisphere is surrounded by a fringe of thin motile processes; the remaining surface of the spermatozoon is cov ...	1980	7388929
the ultrastructure of somatic neuromuscular junctions in the tick amblyomma variegatum (fabr.).	peripheral nerve axons synapse with somatic muscle fibres in the tropical bont tick amblyomma variegatum. each fibre is innervated by numerous terminals; some of the axons synapse more than once. the nerve terminals on coxal muscle fibres contain agranular electron lucent vesicles 50 to 58 nm in size and have the specialised synaptic membranes characteristic of chemically transmitting nerve-muscle junctions. some of the terminals on trochanteral muscle fibres additionally contain larger vesicles ...	1980	7388905
amblyomma americanum: sequential histological analysis of adult feeding sites on guinea pigs.		1980	7371734
performance of ticks fed on rabbits inoculated with extracts derived from homogenized ticks amblyomma maculatum koch (acarina: ixodidae).		1980	7365638
amblyomma americanum: sequential histological analysis of larval and nymphal feeding sites on guinea pigs.		1980	7364007
regulation of body volume by salivation in a tick challenged with fluid loads.	injection into the hemolymph of 1.2% nacl, 11.2% sucrose, 2.3% urea (all approximately isosmotic to hemolymph), or distilled water induced salivary fluid secretion in the ixodid tick amblyomma hebraeum koch. saline gave the largest response at high doses. injection of hyperosmotic nacl into the hemolymph did not induce salivation but led to the drinking of distilled water in amounts sufficient to dilute the salt load to isosmolarity. atropine only partially inhibited salivation induced by nacl, ...	1980	7356041
evidence for a d1 dopamine receptor in the salivary glands of amblyomma americanum (l.).	adenylate cyclase from the salivary gland of the lone star tick, amblyomma americanum, is stimulated by several derivatives of phenylethylamine; dopamine, noradrenaline, adrenaline and isoproterenol. octopamine and iota-dopa had no effect on basal adenylate cyclase activity. dopamine had the highest potency and the lowest ka, 0.4 micron; followed by adrenaline and noradrenaline, 23 micron; and isoproterenol, 0.15mm. when either noradrenaline or adrenaline was added to dopamine, each at its maxim ...	1981	7346526
[amblyomma astrion dönitz, 1909 (ixodidae), a new experimental vector of heartwater disease].		1981	7342212
neurons sensitive to 2,6-dichlorophenol on the tarsi of the tick amblyomma americanum (acari: ixodidae).		1981	7328604
resistance and cross-resistance of guinea pigs to dermacentor andersoni stiles, d. variabilis (say), amblyomma americanum (linnaeus), and ixodes scapularis say.	the ability of guinea pigs to acquire resistance to dermacentor andersoni and amblyomma americanum was determined by repeatedly infesting separate sets of guinea pigs with tick larvae. resistance was measured in terms of reduced numbers successfully engorging and reduced weight of those ticks that engorged. an 83% reduction in numbers of larvae engorging and a 64.5% reduction in the weight of engorged larvae were seen between the first and second infestations with d. andersoni. guinea pigs exhib ...	1981	7328454
human 'seed tick' infestation. amblyomma americanum larvae.		1981	7316562
an investigation into the toxic principle in eggs of the tick amblyomma hebraeum.	a purification procedure involving iso-electric focusing by means of which a toxic principle may be obtained in a pure form from crude egg extracts of amblyomma hebraeum is described. the molecular mass of the toxin is approximately 10 000 according to sedimentation equilibrium sedimentation, sodium dodecyl sulphate (sds) gradient gel electrophoresis and calculations from the amino acid composition. non-competitive proteinase inhibitory activity was found to be associated with the toxin. histopa ...	1981	7312303
cutaneous basophil responses and immune resistance of guinea pigs to ticks: passive transfer with peritoneal exudate cells or serum.	resistance to infestation by larval amblyomma americanum or rhipicephalus sanguineus ticks was transferred to naive guinea pigs with peritoneal exudate cells (pec) or serum from donors immunized by prior infestation with homologous tick larvae. in the a. americanum system, pec transfer induced 87% tick rejection, which was similar to the level of resistance in actively sensitized hosts. in the r. sanguineus system, pec conferred resistance (39% rejection) that was weaker than in actively sensiti ...	1981	7299125
suitability of birds and mammals as hosts for immature stages of the lone star tick, amblyomma americanum (acari: ixodidae).		1981	7288841
some effects of 60co irradiation on cowdria ruminantium in its tick host amblyomma hebraeum koch (acarina: ixodidae).	an attempt was made to attenuate cowdria ruminantium by irradiation of the nymphal stage of its tick host, amblyomma hebraeum. the irradiated nymphs were homogenized and serial dilutions of the resultant suspension were injected intravenously into heartwater-susceptible sheep. no attenuation could be demonstrated but the results indicate that progressively more micro-organisms will be destroyed the higher the irradiation dosage applied, and that dosages between 20 and 30 kilorad apparently prove ...	1981	7279384
response of hypersensitized guinea pigs to the feeding of amblyomma americanum ticks.	guinea pigs acquired resistance to the feeding of immature amblyomma americanum ticks after a single infestation. the initial larval and nymphal feedings resulted in cumulative mortalities of 27.2 and 28.9%, respectively. the second and third larval infestations yielded cumulative mortalities of 50.5 and 52.4%, compared to 18.9 and 24.4% cumulative mortality from controls. second and third nymphal feedings resulted in 75.7 and 73.4%, and ticks from controls exhibited 36.6 and 34.7% cumulative mo ...	1981	7267146
success of tick feeding on calves immunized with amblyomma americanum (acari: ixodidae) extract.		1981	7265136
the effects of the tick amblyomma hebraeum (acari: ixodidae) on blood composition and weight of rabbits.		1980	7218269
arbovirus isolations from ixodid ticks infesting livestock, kano plain, kenya.	in a study conducted on the kano plain, kenya, virus isolation attempts were made on ixodid ticks collected, over a 14-month period, from livestock held in family enclosures (bomas) before releasing the animals for daily foraging. 8735 amblyomma variegatum (fabricius) were tested, 98.6% of which were taken from cattle, yielding 36 strains of dugbe (dug), four strains of nairobi sheep disease (nsd), three strains of bhanja (bha), one strain of thogoto (tho) and five strains of virus which could n ...	1980	7210125
alveolar structure of salivary glands of the lone star tick, amblyomma americanum (l.): unfed females.	alveoli in the salivary glands of unfed amblyomma americanum (l.) females (postnymphal ticks that had not yet taken a bloodmeal as an adult) were studied. as in other species of female ixodid ticks, the salivary glands consisted of three alveoli, one agranular and two granular. the agranular alveoli were directly attached to the anterior portion of the main salivary duct, consisted of approximately 13 to 14 cells, and were without valves. six peripheral cells had tortuous, plasma membrane infold ...	1982	7200514
quantitative studies on the proteins, free fatty acids and glycogen contents of eggs of amblyomma variegatum (fabr) and boophilus decoloratus (koch) (ticks, ixodoidea: ixodidae).		1981	7197866
parasites of domestic and wild animals in south africa. xv. the seasonal prevalence of ectoparasites on impala and cattle in the northern transvaal.	the prevalence of ectoparasites on a total of 36 impala (aepyceros melampus) slaughtered monthly from february 1975 to february 1976 and a total of 24 cattle slaughtered monthly from march 1976 to march 1977 in the nylsvley provincial nature reserve was determined. six species of ixodid ticks were collected from the impala and these, in order of abundance, were: rhipicephalus evertsi evertsi, rhipicephalus appe. diculatus, amblyomma hebraeum, boophilus decoloratus, ixodes cavipalpus and hyalomma ...	1982	7177586
comparative ultrastructure of the spermatids and spermatozoa of the tick hyalomma dromedarii and amblyomma hebraeum (acari: ixodidae).		1982	7153570
antibody- and cell-mediated immune resistance by guinea pigs to adult amblyomma americanum ticks.	naive and actively and passively sensitized guinea pigs were infested with adult amblyomma americanum ticks. naive hosts allowed for 75-81% tick yield, 518-581 mg mean tick weight and an average tick feeding period of 12-13 days. actively sensitized and challenged hosts, however, allowed only 47% tick yield (38.9% rejection), replete individuals were significantly reduced in weight (66.1% weight decrease) and required slightly longer time to feed (14 days). passively sensitized hosts were given ...	1982	7149113
heartwater (cowdria ruminantium infection) on são tomé.	the supernatant obtained after centrifugation of an emulsion of engorged female amblyomma astrion ticks, collected from cattle on the west african island of são tomé, was injected intravenously into a goat, which contracted heartwater. this confirmation of the existence of the disease on the island makes strict control measures necessary if present efforts at improving livestock production by imported exotic cattle are to be successful.	1982	7147672
immune serum transfer of cutaneous basophil-associated resistance to ticks: mediation by 7sigg1 antibodies.	guinea pigs acquired resistance to amblyomma americanum larval ticks after one infestation, resulting in 46% tick rejection when challenged. intravenous transfer of immune serum from twice-infested hosts to naive animals conferred a significant level of immunity resulting in 18 to 30% tick rejection. the minimum effective dose of serum was 3 ml per recipient, and heating the serum at 56 degrees c for 4 hr had no effect on serum activity. fractionation of whole immune serum by gel filtration chro ...	1982	7142697
regulation of feeding and ovipositional success of amblyomma americanum ticks.		1982	7128750
growth in lone star ticks, amblyomma americanum (acari: ixodidae), feeding on cattle: a laboratory study.		1982	7120307
[experimental transmission of the yellow fever virus by the tick amblyomma variegatum (f.) (author's transl)].	experimental transmission of the yellow fever virus by the tick amblyomma variegatum (f.) (the tropical bont tick) is demonstrated for the first time. the tick transmitted the virus from one monkey to another. trans-stasial passage from nymph to adult stage was also demonstrated. the possible role of amblyomma variegatum as a vector and a potential reservoir of yellow fever is discussed.	1982	7105284
relationship between ticks and zebu cattle in southern uganda.	tick populations were observed on zebu (bos indicus) cattle over a period of 2 years at entebbe, uganda where the climate was thought to be highly favourable for the free-living stages of ticks. collections of all instars of ticks were made from the body surfaces of the cattle at intervals of between 1 and 5 weeks. the species recorded in order of decreasing abundance were rhipicephalus appendiculatus, amblyomma variegatum, boophilus decoloratus, rhipicephalus evertsi evertsi, rhipicephalus simu ...	1982	7101465
ablation of immunity to amblyomma americanum by anti-basophil serum: cooperation between basophils and eosinophils in expression of immunity to ectoparasites (ticks) in guinea pigs.	basophils infiltrate the skin and other tissues as part of t lymphocyte and/or antibody-mediated immune responses to certain protein antigens, viruses, tumors, and parasites. although basophils may comprise a significant fraction of leukocytes in these reactions, their precise role has been poorly understood. guinea pigs expressing acquired immunity to the tick amblyomma americanum develop basophil- and eosinophil-rich cutaneous inflammatory responses at tick feeding sites, and tick rejection is ...	1982	7086142
amblyomma ticks found on cattle in the northwest of argentina. preliminary report.	the phytogeographical and seasonal distributions of three species of amblyomma ticks found on cattle are presented. the material studied was collected during a four-year survey in the northwest of argentina. amblyomma neumanni shows predilection for the chaqueno serrano district although it was also found in ecotones (phytogeographical transition zones) of the adjacent western chaqueno district and the province of las yungas. amblyomma cajennense was found in the western chaqueno and chaqueno se ...	1982	7081892
blood eosinophil and basophil responses in guinea pigs parasitized by amblyomma americanum ticks.	guinea pigs sensitized to tick feeding by a previous infestation express immune resistance when challenged. this state is associated with large accumulations of eosinophils, and especially of basophils, at cutaneous sites of tick feeding. the present study shows that primary and secondary tick feeding stimulate blood eosinophilia and basophilia that reflect the infiltration of these cells in the skin. primary feeding of amblyomma americanum larvae resulted in a mean tick yield of 81%, mean tick ...	1982	7081550
protein changes in the salivary glands of the female lone star tick, amblyomma americanum, during feeding.		1982	7077436
tick paralysis in brazil.	from july to december 1977 and from june to november 1978 the toxic effects of amblyomma cajennense were studied in cattle sheep and goats. locomotor disturbances commencing as hind-limb paralysis ascended to the upper nervous centres causing paralysis. this was observed in natural infections and confirmed experimentally. tick paralysis is reported for the first time in brazil, manifesting itself in a different form to that usually attributed clinically to the disease. also for the first time re ...	1983	6868132
metazoan parasites of the eastern cottontail rabbit in western kentucky.	forty-five eastern cottontail rabbits (sylvilagus floridanus allen), collected over a 15 mo period from two areas of western kentucky, were examined for disease conditions, helminth and arthropod parasites. a single lymphosarcoma, two cutaneous papillomas and the following parasites were identified: hasstilesia tricolor, taenia pisiformis, cittotaenia variabilis, raillietina stilesiella, obeliscoides cuniculi, trichuris leporis, longistriata noviberiae, trichostrongylus calcaratus, dermatoxys ve ...	1983	6842731
epidemiology and transmission of theileria sp of cattle in australia.	theileria sp occurs in cattle in australia where boophilus microplus is not present. two species of ixodid ticks namely haemaphysalis longicornis and h. bancrofti have been implicated as natural vectors. experimental transmission was obtained with these two species but attempts to transmit the infection with b. microplus, ixodes holocyclus and amblyomma triguttatum were not successful. although calves born in the enzootic area may become infected before one-month-old most show evidence of infect ...	1982	6818938
causal agents of bovine theileriosis in southern africa.	one pathogenic and 4 mild bovine theileria strains from southern africa, all transmitted by rhipicephalus appendiculatus, were compared amongst themselves as well as to bovine and buffalo strains of the t. parva complex from eastern and southern africa and to bovine strains of t. taurotragi from tanzania considered to be derived from eland antelope. criteria used were parasitological, clinical, serological and cross-immunity characters. the mild strains are similar to bovine t. taurotragi. serol ...	1982	6812250
experimental transmission of cowdria ruminantium by the gulf coast tick amblyomma maculatum: danger of introducing heartwater and benign african theileriasis onto the american mainland.	the tick amblyomma maculatum proved to be an experimental vector of cowdria ruminantium, the cause of heartwater of ruminants. transstadial transmission from larva to nymph and from larva through nymph to adult was successful; however, an experiment on transovarial transmission gave negative results. neither a americanum nor a cajennense transmitted the infection. there is a potential danger of the disease gaining access to the american mainland from the caribbean where it is known to occur and ...	1982	6808870
antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern connecticut.	blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (sfg) rickettsiae during 1978-1980 in southern connecticut. of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against rickettsia montana (n = 34), r rickettsii (n = 31), r rhipicephali (n = 19), or the unclassified 369-c rickettsia (n = 90). end points greater than or equal to 1:8,192 to r rickettsii and to r r ...	1982	6803626
observations on the transmission of theileria mutans in south africa.	four isolates of theileria mutans obtained from geographically distant parts of south africa by subinoculation of infected blood were found to be readily transmitted by the bont tick amblyomma hebraeum. all attempts to transmit these isolates with rhipicephalus appendiculatus were unsuccessful. possible explanations for differences between these results and those reported by earlier workers in this country are discussed.	1981	6792579
mammalian wildlife diseases as hazards to man and livestock in an area of the llanos orientales of colombia.	development of the llanos orientales of colombia, and access to underdeveloped areas in the llanos, may create disease hazards to man and domestic animals or introduce exotic pathogens, creating reservoirs of infection for domestic animals and acting as limiting factors on the native wild species. a survey of wild animals common to the llanos revealed a number of parasites indigenous to the area. a total total of 59 mammalian species, representing eight orders were examined. haematozoa were repr ...	1981	6788961
development of theileria mutans (theiler, 1906) in the gut and the haemolymph of the tick amblyomma variegatum (fabricius, 1794).	the development of theileria mutans in the gut and haemolymph of its tick vector, amblyomma variegatum, was studied by giemsa-stained smears after the nymphal tick had completed engorgement on parasitaemic calves. sexual stages occurred in the gut between five and seven days after repletion. the zygotes were observed in the gut from day 29 and the kinetes from day 30, i.e. three and four days after the nymphs moulted to adults. from day 34 kinetes were observed in the haemolymph. the development ...	1980	6771935
[seasonal dynamics in the development of boophilus microplus and amblyomma cajennense in camagüey, cuba].	studies were carried out on the occurrence of the ixodic ticks in farm animals in the province of camagüey, cuba. most spread proved to be the boophilus microplus and amblyomma cajennense species. as many as three waves of parasitic activity were seen with b. microplus: at the end of the winter season, in the months of may and june, and in the autumn (october and november). only one wave was there with the activity of a. cajennense, covering the period of march-september.	1984	6740935
isolation and transmission of cowdria ruminantium (causal agent of heartwater disease) in blue nile province, sudan.	heartwater was diagnosed in sheep at the umm banein livestock research station, blue nile province, sudan. cowdria ruminantium was isolated from sheep by subinoculation of blood into a goat. adult amblyomma lepidum ticks fed as nymphs on this goat transmitted heartwater to a friesian (bos taurus) calf. brain stabilates from this calf, either snap-frozen into liquid nitrogen or frozen slowly in a deepfreezer at -70 degrees c, with dmso as cryoprotectant, were infective to cattle when inoculated s ...	1984	6740919
ixodid ticks on feral swine in florida.	more than 99% of the 645 feral swine (sus scrofa l.) in southern florida harbored ixodid ticks. dermacentor variabilis (american dog tick) was present on 99.6% of the swine and comprised 82.5% of the ticks collected. amblyomma maculatum (gulf coast tick) occurred on 85.9% of the hosts and 17.4% of the collections were of this species. amblyomma americanum (lone star tick) and ixodes scapularis (black-legged tick) were found infrequently and together constituted less than 0.1% of the ticks. pigs ...	1984	6737605
susceptibility of ticks to acaricides in zambia.	the susceptibility of some zambian ticks to dieldrin, dioxathion, dimethoate and chlorfenvinphos was determined on two- to three-week-old larvae of amblyomma variegatum, boophilus decoloratus, b. microplus, rhipicephalus appendiculatus, r. e. evertsi and a member of the r. pravus group. some strains of b. decoloratus and r. appendiculatus were resistant to dieldrin, dioxathion and dimethoate and some r. e. evertsi were resistant to dieldrin and dioxathion. a single strain of an r. pravus group t ...	1984	6730000
development of ixodid ticks under natural conditions in nigeria.	the developmental periods of five tick species were recorded from egg to adult stages under natural conditions. the ticks were amblyomma variegatum, boophilus decoloratus, b. geigyi, hyalomma rufipes and h. truncatum and the natural condition was a grazing field on which "open" site and "shade" were recognised. the investigation took place between april 1980 and march 1981. the hatching patterns of larvae, attachment, engorgement, larvo-nymphal and nympho-adult moulting periods and the survival ...	1984	6729999
studies on ticks of veterinary importance in nigeria. viii. differences observed in the biology of ticks which fed on different domestic animal hosts.	ticks of the species amblyomma variegatum (fabr.), boophilus decoloratus (koch), boophilus geigyi aeschl. et morel, and hyalomma rufipes koch were detached from cattle, sheep and horses and the influence of these various hosts on the biology of ticks was investigated. no a. variegatum was found in horses. the parameters studied were preoviposition and oviposition periods, ovipositional capacity, eclosion period, hatching patterns, egg sizes and temperature effect. although the preoviposition and ...	1984	6714846