Publications

description of a gland associated with the foveae dorsales in 2 species of dermacentor ticks, and its possible role in sex pheromone activity (metastigmata: ixodidae).		1975	1181432
ecological observations on dermacentor albipictus (packard) in eastern oklahoma (acarina: ixodidae).		1975	1181450
[ability of female ixodid ticks to recover from poisoning with ddt in the process of feeding].	ability of hungary females of ixodes persulcatus, haemaphysalis concinna and dermacentor silvarum to feed and lay eggs after having been exposed to different ddt doses (ld100) has been studied. the ticks heavily injuried but still mobile can feed on the host and lay eggs, i.e. to overcome the poisoning. clutches laid by these females do not differ from control ones. loss of mobility deprives the ticks of the ability to fed. an increase in ddt dose (ld100 x 100, experiment with i. persulcatus) do ...	1975	1187171
cryptoxanthin--a dominating carotenoid in the meadow tick (dermacentor pictus hermann).		1975	1192246
recent records of ticks, ixodes cookei packard and dermacentor variabilis (say) (acarina: ixodoidea) in southwestern ontario.		1975	1193021
relationships of immature dermacentor variabilis (say) (acari: ixodidae) with the white-footed mouse, peromyscus leucopus, in southwestern wisconsin.		1975	1195285
notes on the role of ticks feeding on lagomorphs and ingestion of ticks by vertebrates in the epidemiology of rocky mountain spotted fever.		1975	1195301
the effect of mean winter temperature around 0 degrees c on the population size of the american dog tick, dermacentor variabilis, say. (acarina: ixodidae).		1975	1211069
[anatomical age changes of empty imago ixodes ticks (physiological age)].		1975	1214721
[ecology of the tick, dermacentor silvarum o1].	results of the experiments have shown that the development of dermacentor silvarum from egg to imago varied from 44 to 46 days at 28 c and redundant humidity and from 50 to 52 days at 25 degrees c. the thermic threshold of larval development lies within a range of 8.6 degrees c, that of nymphs-9.7 degrees c. a sum of effective temperatures required for larval development averaged 123.5 degrees c, for nymphs-225 degrees c and for the whole ontogenesis-from 570 to 690 degrees c. in the north of th ...	1975	1221338
acquired resistance to ticks. i. passive transfer of resistance.	guinea-pigs developed resistance to larvae of the ixodid tick, dermacentor andersoni, after one infestation. resistance was characterized by guinea-pigs allowing fewer larvae to engorge (5-15%) during a second exposure than during an initial infestation (70-90%). larvae feeding on resistant hosts weighed less than larvae engorging on a host with no previous exposure to ticks. evidence is presented which indicates that this resistance can be passively transferred with viable lymph node cells, but ...	1976	1254319
contributions to the ecology of colorado tick fever virus. 2. population dynamics and host utilization of immature stages of the rocky mountain wood tick, dermacentor andersoni.		1976	1263215
[determination of natural foci of tularemia in the tuva assr].	eleven strains of tularemia causative agents were isolated in 1974 in bacteriological study of ixodes ticks dermacentor nuttalli (13088 in all) by biotests on albino mice. tularemia was confirmed retrospectively in two humans who contracted the disease from ondatra cadavers. skin allergic test with tularin was used to examine 1733 residents of seven populated localities; a positive result was obtained in 2 persons. finally, in examination of 240 sera of cattle agglutination reaction proved to b ...	1976	1266472
acquired resistance to ticks. ii. effects of cyclophosphamide on resistance.	guinea-pig developed resistance to dermacentor andersoni larvae after one infestation. cyclophosphamide administered in one dose (300 mg/kg) 48 hr prior to an initial infestation with larvae blocked the acquisition of resistance. when cyclophosphamide was given in a similar regimen to guinea-pigs which had already acquired resistance, the expressin of resistance was partially blocked. it was proposed that the blockage of the acquisition of resistance further confirmed the immunological nature of ...	1976	1270085
[a trial at using the systemic action of ivermectin for suppressing the vector capacity of ticks (ixodidae) infected with the tick-borne encephalitis virus].	adult dermacentor marginatus hatched from nymphs infected with tbe virus and poisoned with ivermectin retain their vector abilities. even small individuals with a 1.5-2 times lesser mass as against the reference mass contain the virus in the body in the same titers and the virions in salivary gland alveoli. administration of an oil solution of ivermectin into the stomach of white mice, nymph feeders, in a dose surpassing threefold the dose recommended for intramuscular injection of this agent co ...	1992	1299761
[differences in the distant transmission of the tick-borne encephalitis virus by ixodid ticks of 2 subfamilies].	simultaneous but separate feeding of ticks on nonviremic animal (guinea pig) has shown that amblyomminae ticks are practically unable to transmit distantly tick-borne encephalitis virus (tbev) to the specimens of their own subfamily and to ixodinae as well. ixodes persulcatus and i. ricinus displayed their ability as donors and recipients of tbev (adults and nymphs) not only for their own subfamily representatives but also as donors for recipients of amblyomminae subfamily (nymphs and adults of ...	1992	1299805
[plant smells---important determinants in the behavior and rate of development of ixodid disease vectors].	experiments with nymphs of ixodes persulcatus and dermacentor marginatus have shown that the rate and degree of engorgement, dropping off from the mouse, metamorphosis longevity and weight of emerging imagoes change under plant odour influence. the influence of acetone extract vapours of pepper, poplar buds, linden and aspen was tested. under the influence of the vapour, acting as an attractant for the adults, engorgement weight of their nymphs and the weight of imagoes emerging from them increa ...	1992	1364524
[an assessment of the status of natural foci of crimean-congo hemorrhagic fever in the crimea].	the parasitological data and the results of the virological and serological investigations of materials, collected in nature and in the course of study of the immune structure of the population, are indicative of the circulation of chf virus in the crimea and the possibility of human infection. data on spontaneous infection of four species of ixodes ticks with chf virus have been confirmed, including the data, obtained for the first time for this region, on the participation of dermacentor margi ...	1992	1379771
changes in population density and distribution of ixodes dammini (acari: ixodidae) in wisconsin during the 1980s.	changes in the density and distribution of ixodes dammini, spielman clifford, piesman & corwin were assessed in wisconsin by examining hunter-killed deer for ticks in 1981 and 1989. deer examination sites were distributed widely across the state and included 23 sites in 1981 and 15 sites in 1989; 10 sites were visited both years. between 1981 and 1989, i. dammini became more abundant throughout its range, and i. dammini range expanded into the southwestern portion of wisconsin. i. dammini was no ...	1992	1404249
parasitic arthropods of sympatric meadow voles and white-footed mice at fort detrick, maryland.	twelve species of parasitic arthropods (one sucking louse, two fleas, one tick, and eight mites) were recovered from 51 meadow voles, microtus pennsylvanicus (ord); whereas nine species (one sucking louse, one bot, three fleas, one tick, and three mites) were collected from 48 white-footed mice, peromyscus leucopus (rafinesque), live-trapped on the grounds of fort detrick, frederick county, md., during 1990 and 1991. the most commonly collected arthropods from m. pennsylvanicus were the fur mite ...	1992	1404254
modulation of host-immune responses by ticks (acari: ixodidae): effect of salivary gland extracts on host macrophages and lymphocyte cytokine production.	ixodid tick infestation induces host acquired resistance, which involves immunoglobulin cell-mediated and complement-dependent effector pathways. ticks have developed countermeasures to modulate host antiarthropod responses. ixodid-mediated host immunomodulation results in vitro in reduced responsiveness to t-lymphocyte mitogens for cells obtained from infested hosts and impaired antibody responses to a thymic dependent antigen. salivary gland extracts from days 0-9 of engorgement from unmated, ...	1992	1404261
cotton rats and other small mammals as hosts for immature dermacentor variabilis (acari: ixodidae) in central oklahoma.	eight species of small mammals were evaluated as potential hosts for american dog ticks, dermacentor variabilis (say), in an upland, tallgrass prairie study site in central oklahoma. only hispid cotton rats, sigmodon hispidus, and deer mice, peromyscus maniculatus, were found to be important hosts for immature d. variabilis. although d. varibilis larvae and nymphs frequently infested both cotton rats and deer mice, cotton rats were the most important host species for both immature stages in the ...	1992	1404263
[the tick fauna of eastern germany].	the occurrence of several tick species in selected areas of eastern germany is described. from may 1987 till december 1989 8,472 ticks from 430 places were examined. ixodidae of the genus ixodes, dermacentor and haemaphysalis as well as argasidae of the genus argas were identified. the most common species was ixodes ricinus. furthermore, an endemic area of dermacentor reticulatus was detected in the düben-dahlen and annaburg health. two other species of ticks, which were found frequently and som ...	1992	1416225
tick infection rates with borrelia: ixodes ricinus versus haemaphysalis concinna and dermacentor reticulatus in two locations in eastern germany.	unfed nymphal ixodes ricinus, haemaphysalis concinna, and adult dermacentor reticulatus were collected in two locations of saxony in july and september 1991 by flagging. in july, the abundance of nymphal i. ricinus was about 2-3 times higher than that of nymphal h. concinna, a time of the year when nymphs of both species are reported to have a seasonal peak of activity. no d. reticulatus were flagged concurrently. in september, host-seeking activity of nymphal i. ricinus was again quite high as ...	1992	1463902
[human babesiosis. study of vectors].	babesiosis in an entity transmitted by tick bite presented in our medium producing high morbidity and mortality in immunodepressed patients.	1992	1489774
tick (acari: ixodidae) attachment cement and salivary gland cells contain similar immunoreactive polypeptides.	a specific antiserum (12c) raised to a 90-kda immunogenic component of salivary glands of the tick rhipicephalus appendiculatus recognized similar 90-kda polypeptides from salivary glands of the american dog tick, dermacentor variabilis, and the lone star tick, amblyomma americanum, as well as 70-kda polypeptides in the cement of d. variabilis, a. americanum, and r. sanguineus (brown dog tick). the reduction in size of the polypeptide for these ticks suggests that it is modified in some way duri ...	1992	1495047
effects of temperature and humidity on ovipositional biology and egg development of the tropical horse tick, dermacentor (anocentor) nitens.	the ovipositional biology and egg development of the tropical horse tick, dermacentor (anocentor) nitens (neumann), was observed at four temperatures (20, 25, 30, and 35 degrees c) and relative humidities (40, 61, 75, and 91% rh). relative humidity had little effect on length of preoviposition and oviposition periods. with increased rearing temperatures, there was a decrease in both preoviposition and oviposition periods. oviposition rate increased with temperature and was not affected by relati ...	1992	1495053
tick sweep: modification of the tick drag-flag method for sampling nymphs of the deer tick (acari: ixodidae).	we describe a version of the standard tick drag-flag modified for use in close-growing and tangled vegetation, as well as under ornamental shrubbery and fallen branches. two major features of the sweep are: (1) it allows the user to remain upright with the flag parallel to the ground, thus sampling effectively beneath low and fallen branches and around shrubs, as well as capturing host-seeking ticks in advance of the operator; and (2) the use of a flannel rubberized-laminate fabric (crib sheet) ...	1992	1495058
isolation of borrelia burgdorferi (spirochaetales: spirochaetaceae) from ixodes scapularis and dermacentor albipictus ticks (acari: ixodidae) in oklahoma.	borrelia burgdorferi was isolated from ixodes scapularis say and dermacentor albipictus packard that were removed as partially fed adults from white-tailed deer, odocoileus virginianus zimmermann, in oklahoma. isolation in media was accomplished only after homogenates of pooled field-collected ticks were inoculated into laboratory-reared peromyscus leucopus and reisolated from the urinary bladder into bsk ii media. both isolates were confirmed by western blot analysis and reactivity with monoclo ...	1992	1495072
persistence of anaplasma marginale (rickettsiales: anaplasmataceae) in male dermacentor andersoni (acari: ixodidae) transferred successively from infected to susceptible calves.	the persistence of anaplasma marginale theiler in male dermacentor andersoni stiles ticks exposed to the organism as adults was studied as the ticks were successively transferred to five susceptible calves. all calves fed upon by these ticks rapidly developed clinical anaplasmosis; incubation periods of infection ranged from 19 to 26 d and did not change significantly with successive feedings. development of a. marginale in tick midgut and salivary glands was followed daily during tick feeding ( ...	1992	1495076
attempted transmission of borrelia burgdorferi (spirochaetales: spirochaetaceae) (jdi strain) by ixodes scapularis (acari: ixodidae), dermacentor variabilis, and amblyomma americanum.	laboratory-reared ixodes scapularis say, amblyomma americanum (l.), and dermacentor variabilis (say) were fed on new zealand white rabbits experimentally infected with borrelia burgdorferi (jdi strain). at repletion, spirochetes could be detected by dark-field microscopy only in i. scapularis. acquisition rates were 18 and 21%. when previously exposed nymphs of each species were fed on susceptible rabbits, i. scapularis was the only tick of the three species that transmitted b. burgdorferi. when ...	1992	1495078
borrelia sp. in ticks recovered from white-tailed deer in alabama.	six hundred sixty-five hunter-killed white-tailed deer (odocoileus virginianus) from 18 counties in alabama (usa) were examined for ticks. most of the collections were made at state-operated wildlife management areas. four species of ticks (n = 4,527) were recovered: the lone star tick amblyomma americanum (n = 482); the gulf coast tick a. maculatum (n = 11); the winter tick dermacentor albipictus (n = 1,242); and the black-legged tick ixodes scapularis (n = 2,792). fifty-six percent of the tick ...	1992	1512879
ectoparasites of the blackbuck antelope (antilope cervicapra).	fifty-two free-ranging blackbuck antelope (antilope cervicapra) from texas were examined for ectoparasites. two species of sucking lice (anoplura), one species of chewing louse (mallophaga), one species of louse fly (diptera), and three species of ticks (acari) were found. this is the first report of the anoplurans linognathus cervicaprae and l. pithodes from the western hemisphere. the southern deer ked (lipoptena mazamae), the winter tick (dermacentor albipictus), and the rabbit tick (haemaphy ...	1992	1512888
detection of rickettsia rickettsii in saliva, hemolymph and triturated tissues of infected dermacentor andersoni ticks by polymerase chain reaction.	the technique of polymerase chain reaction (pcr) is potentially superior to existing methods for detecting rickettsial infections in ticks. for this reason, we developed assays for identifying rickettsial infections in ticks by pcr. our assays amplified a 500 bp fragment from the gene encoding the romp b protein of rickettsia rickettsii. the selected primers amplified fragments of the predicted size from all spotted fever group rickettsiae (r. rickettsii, r. parkeri, r. conorii, r. sibirica) tes ...	1992	1528203
diversity of tick species biting humans in an emerging area for lyme disease.	although most tick bites in humans in areas of the northeastern united states in which lyme disease is highly endemic are due to ixodes dammini, no study documents the frequency of i. dammini bites in low-prevalence or emerging areas for lyme disease. data on the proportion of tick bites in humans that are due to i. dammini in a region may have implications for public health policy and clinical management.	1992	1536337
susceptibility of two rocky mountain bighorn sheep to experimental infection with anaplasma ovis.	in north america, the role of wild ruminants in the epidemiology of anaplasmosis has not been clearly defined. such information is particularly meager in regard to bighorn sheep. we report the susceptibility of two rocky mountain bighorn sheep (ovis canadensis canadensis) to experimental infection with a well characterized field isolate of anaplasma ovis obtained from domestic sheep in idaho. both bighorn sheep developed infection resulting in severe clinical disease, with relatively high parasi ...	1992	1548791
distribution, density, and lyme disease spirochete infection in ixodes dammini (acari: ixodidae) on white-tailed deer in maryland.	a statewide survey of ticks parasitizing white-tailed deer was carried out in maryland during november 1989 to assess the status of the deer tick, ixodes dammini spielman, clifford, piesman & corwin, the major vector of lyme disease in the northeastern united states. ticks were collected from deer carcasses brought in by hunters at 23 check stations (one per county). a total of 3,437 i. dammini were collected from 538 of 1,281 deer (42%), together with 2,013 dermacentor albipictus (packard) and ...	1992	1552529
development of anaplasma ovis (rickettsiales: anaplasmataceae) in male dermacentor andersoni (acari: ixodidae) transferred from infected to susceptible sheep.	the development of anaplasma ovis was studied in dermacentor andersoni males transferred from infected to susceptible sheep. laboratory-reared male d. andersoni were allowed to feed for 6 d on a sheep with ascending a. ovis parasitemia. the ticks were removed and held at room temperature in a humidity chamber for 6 d, after which they were allowed to feed on five susceptible sheep for 1, 3, 5, 7, or 9 d. gut and salivary glands were collected from ticks during the 21-d experiment and examined wi ...	1992	1552534
[q fever endemic in the palatinate].	in 1989 investigations revealed a small scale outbreak of q fever in the area of vorderpfalz several kilometers west of the city of ludwigshafen/rhein. in 16 cases the diagnosis of q fever has been serologically confirmed by complement fixation test (cf), the estimated number of unknown cases, however, may be considerable. a flock of sheep was determined as the source of infection. due to the prevalence of the tick species dermacentor marginatus, one of the main vectors of the infection, the are ...	1992	1579564
development of anaplasma marginale in male dermacentor andersoni transferred from parasitemic to susceptible cattle.	the development and transmission of anaplasma marginale was studied in dermacentor andersoni males. laboratory-reared male d andersoni were allowed to feed for 7 days on a calf with ascending a marginale parasitemia. the ticks were then held in a humidity chamber for 7 days before being placed on 2 susceptible calves. anaplasmosis developed in the calves after incubation periods of 24 and 26 days. gut and salivary glands were collected from ticks on each day of the 23-day experiment and examined ...	1992	1586018
a redescription of schizogony of cytauxzoon felis in the domestic cat.	cytauxzoon felis is a protozoan parasite that is transmitted by dermacentor variabilis ticks and causes a uniformly fatal disease in domestic cats. in order to study schizogony and merozoite formation, d. variabilis nymphs were allowed to feed on domestic cats experimentally infected with c. felis, after which the molted adult ticks were fed on susceptible cats. lung and liver tissues were collected from the cats during clinical cytauxzoonosis and were fixed for light and transmission electron m ...	1992	1626865
recent advances in the biology of anaplasma spp. in dermacentor andersoni ticks.		1992	1626880
preliminary attempts to infect bovine erythrocytes in vitro with a tick-derived stage of anaplasma marginale.		1992	1626895
toxic effect of endocytobionts from dermacentor reticulatus ticks in three tick species after in vivo application.	the endocytobionts from ovaries of partially engorged female dermacentor reticulatus ticks, inoculated introcoelomally into females of three tick species, d. reticulatus, ixodes ricinus and haemaphysalis inermis, caused considerable morphological alterations in the examined cells and tissues of the synganglion, fat body, tracheal complex and ovary of these recipients.	1992	1638925
the role of the fat body, midgut and ovary in vitellogenin production and vitellogenesis in the female tick, dermacentor variabilis.	polyclonal antibodies directed against d. variabilis vitellin were utilized for immunocytochemistry at the ultrastructural level. we localized vitellogenin (vg) in rough endoplasmic reticulum cisternae, secretory granules and secreted products of fat body trophocytes and midgut vitellogenic cells from feeding and ovipositing females. vg was localized in the oocyte golgi bodies and in the yolk bodies of both feeding and ovipositing females. uptake of exogenous vg was indicated by the presence of ...	1992	1639570
ivermectin is not an agonist at a gaba receptor in tick salivary glands.	the avermectins, broad-spectrum anti-parasitic agents which are effective against ticks, act principally by stimulating gamma-aminobutyric acid (gaba) receptors directly or indirectly. gaba is known to potentiate dopamine-induced fluid secretion in the salivary glands of female ixodid ticks. we thus tested whether 10 microm ivermectin would have an effect similar to gaba in the isolated salivary gland preparation of dermacentor andersoni. ivermectin was not an agonist at this gaba receptor.	1991	1660804
mixed rickettsia-virus infection in dermacentor reticulatus imago.	electron microscopic examination revealed replication and accumulation of rickettsia sibirica in the fat body of experimentally infected dermacentor reticulatus ticks. rickettsia are released from the fat body cells by budding being surrounded with cytoplasm and plasmalemma of the host cell. eukaryotic cell structures have been detected consisting of lamella layers whirled around the intact rickettsiae. in addition to rickettsia, microorganisms morphologically resembling francisella tularensis a ...	1991	1681715
coxiella and rickettsiella: comparison of ultrastructure with special reference to their envelope.	ultrastructure of rickettsiella phytoseiuli (r.p.) multiplying in female ticks dermacentor reticulatus was compared with that of coxiella burnetii (c.b.) in the same ticks and in mice. c.b. in ticks and mice were always represented by 2 main cell types: small dense round or rod-like cells (dc) and larger bacteria-like cells (bc). dc were surrounded with a characteristic five-layered 20 nm thick envelope. under the envelope dc had a stack of parallel intracytoplasmic membranes with a periodicity ...	1991	1687641
salivary gland antigens of ixodes dammini are glycoproteins that have interspecies cross-reactivity.	serum from rabbits and rats exposed to ixodes dammini adults and larvae, respectively, contain antibodies to a large number of antigens in salivary gland homogenates from adult ticks that cross react with the antigens of a closely related species, ixodes scapularis, and significantly with dermacentor variabilis antigens. the salivary gland antigens of i. dammini are glycoproteins composed of both n- and o-linked carbohydrate chains. the antigenic determinants reside in both the polypeptide and c ...	1991	1723426
rickettsiae and borrelia burgdorferi in ixodid ticks.	nymphs and adults of hard-bodied ticks were collected in connecticut and tested by direct and indirect immunofluorescence staining methods for rickettsiae and borrelia burgdorferi. of the 609 ixodes dammini ticks examined, 59 (9.7%) harbored rickettsialike microorganisms in hemocytes (blood cells). these bacteria reacted with fluorescein-conjugated antiserum to ehrlichia canis, the etiologic agent of with fluorescein-conjugated antiserum to ehrlichia canis, the etiologic agent of canine ehrlichi ...	1991	1757551
tick infestations of white-tailed deer in alabama.	four species of ticks were collected from 537 white-tailed deer (odocoileus virginianus), examined during the hunting seasons (november to january) of 1988-89 and 1989-90 at selected locations in alabama (usa). ixodes scapularis was the most common tick recovered (2,060 specimens) and infested 54% of the deer. dermacentor albipictus was the second most frequent tick (1,253 specimens) and infested 15% of the deer. amblyomma americanum was the third most frequent tick (315 specimens) and infested ...	1991	1758026
[an evaluation of the status of natural foci of crimean-congo hemorrhagic fever in the crimea].	parasitological data, the results of virological and serological investigations of materials, collected in nature and during the study of the immune structure of the population and indicative of the circulation of cchf, virus in the crimea and the possibility of human infection, are presented. the data on the spontaneous cchf virus infection of 4 tick species belonging to the genus ixodes have been confirmed, and evidence on the participation of dermacentor marginatus in this process obtained fo ...	1991	1759520
ectoparasites of commensal rodents in sulawesi utara, indonesia, with notes on species of medical importance.	ectoparasite records are presented for four species of commensal murid rodents (rattus rattus palelae miller & hollister, r. argentiventer (robinson & kloss), r. exulans (peale) and mus musculus castaneus waterhouse) in sulawesi utara, with particular reference to the potential for these arthropods to bite and transmit pathogens to humans. the flea, xenopsylla cheopis (rothschild), was most common on r.r. palelae and is capable of transmitting plague and other pathogens to humans although no cur ...	1991	1768888
rectal infusion and aspiration of material through the guts of ixodid ticks (acari: ixodidae).	a technique for inoculating and removing substances via the anus of vector ticks was devised to define features of vector competence precisely. calibrated inocula (greater than 5 nanoliter) containing aqueous dye and polystyrene beads as well as infectious agents were infused into the rectal sacs of ticks using glass microcapillary pipettes placed within the expanded anal orifice. the guts of preadult and adult ticks, ixodes dammini spielman, clifford, piesman & corwin, dermacentor variabilis (s ...	1991	1770516
[the development of methods for the absolute count of the population of ixodid pasture ticks in open landscapes. 3. the count of hungry dermacentor nuttalli olen., 1919 larvae and nymphs in the steppe regions of the transbaikal area].	methods for absolute registration of the number of hungry larvae and nymphs directly in the places of their natural habitation have been elaborated. specific features of the activation of these phases in transbaikal conditions have been studied. peaks of their seasonal activity can be observed in july. it has been shown that the results of single (during seasonal peak in their number) capture of larvae and nymphs from all animal holes over a 100 m2 area can be used for characterization of densit ...	1991	1770885
[the correlation variability of the morphometric traits in 4 species of ixodid tick species (ixodidae)].	correlation analysis of 10 characters was run in three species of dermacentor, d. nuttalli, d. ushakovae, d. niveus, and in ixodes persulcatus, separately for each phase and sex. correlation coefficients are very low in larvae of all species. in male nymphs correlation coefficients are on the same level in all species while the correlation coefficient level in female nymphs reflects the degree of independence of the development of characters. this defines the degree of manifestation of sexual di ...	1991	1792099
[a trial of cultivating rickettsiella phytoseiuli on the sm imv-72 medium used for growing phytopathogenic mycoplasmas].	the work presents data on growing rickettsiella phytoseiuli in the sm imv-72 medium which is used for cultivation of phytopathogenic mycoplasmas. rickettsiella was observed till the 66th day in the primary cultures and till the 16th day after the first passage. binary division of the cells has been found only in the primary cultures; a complex cycle of the rickettsiella development ceased at the stage of formation of the crystal-forming cells. attempts to passivate rickettsiella were failure.	1991	1819757
endocytobionts in dermacentor reticulatus ticks (ixodidae): an electron microscope study.	endocytobionts (ecbs) were detected in the ovaries of dermacentor reticulatus. their developmental cycle is directly related to the developmental stages of tick oocytes. two basic forms of ecbs occur in tick cells, i.e. dense forms, occurring singly or in aggregates situated free in the cytoplasm of host cells, and the light forms which are larger, pleomorphic and always situated inside vacuoles of host cells. the light forms occur together with dense forms in all oocytes. the dense forms occur ...	1991	1860417
role of genital sex pheromones in amblyomma americanum and a. maculatum (acari: ixodidae).	amblyomma americanum and a. maculatum were studied to determine if genital sex pheromones were present, as reported in dermacentor species. chemical analysis of methanol extracts of the anterior reproductive tracts (source of the genital sex pheromone) of a. americanum and a. maculatum confirmed the presence of the same fatty acids that act as components of the genital sex pheromone in dermacentor variabilis and d. andersoni. in both amblyomma species, removal of the anterior reproductive-tract ...	1991	1860418
[the ultrastructure of the interaction of rickettsia sibirica and r. slovaca with the cells of ixodid ticks].	the ultrastructural aspects of the interaction of r. sibirica and r. slovaca with cells of mites of the species dermacentor reticulatus, d. marginatus and ixodes ricinus after their parenteral infection, as well as in the organs of d. marginatus infected naturally in the environment, have been studied. both rickettsial species have similar morphology in different organs of the vector. these rickettsiae not only multiply, their populations are also partly destroyed in phagolysosomes. the natural ...	1991	1867038
tick resistance in mast cell-deficient mice: histological studies.	mast cell-deficient w/wv mice and their mast cell-sufficient +/+ genetic controls were allowed to undergo three successive infestations with dermacentor variabilis larvae. histological examination of the skin of infected mice revealed large dermal accumulations of eosinophils and smaller numbers of neutrophils. the numbers of both eosinophils and neutrophils increased significantly in w/wv and +/+ mice during secondary and tertiary infestations. mast cell numbers were also found to increase in t ...	1991	1869363
venezuelan equine encephalomyelitis virus infection in and transmission by the tick amblyomma cajennense (arachnida: ixodidae).	to assess a possible role of ticks as the maintenance host for epizootic strains of venezuelan equine encephalomyelitis (vee) virus, laboratory experiments were conducted to determine if ticks could become infected, maintain, and transmit the virus. larval and nymphal amblyomma cajennense (f.) and larval dermacentor nitens neumann ticks were exposed to epizootic vee virus (trinidad donkey strain) by allowing them to feed on viremic guinea pigs (strain 13). in a. cajennense, transstadial transmis ...	1991	1875367
ectoparasites of a population of urban gray squirrels in northern florida.	ectoparasites infesting a population of urban gray squirrels (sciurus carolinensis gmelin) in northern florida were collected monthly during 1974. eleven species were identified: one flea (orchopeas howardi (baker], three suckling lice (enderleinellus longiceps kellogg & ferris, hoplopleura sciuricola ferris, and neohaematopinus sciuri jancke), one tick (dermacentor variabilis say), two mesostigmatid (gamasid) mites (androlaelaps casalis (berlese) and a. fahrenholzi (berlese], and four chiggers ...	1991	1875375
effect of ivermectin on the volume of blood ingested by two species of ticks (acari: ixodidae) feeding on cattle.	females of the lone star tick, amblyomma americanum (l.), and the american dog tick, dermacentor variabilis (say), were fed on ivermectin (ivomec)-treated and untreated bovines to determine the effect of the acaricide on volume of blood ingested and to compare the weight differences between the treatment and control groups at various time intervals after attachment. adult females from each genus were collected from bos tarus hosts and subjected to hematin assays on three collection dates to esti ...	1991	1875376
a review of the ixodid ticks (acari, ixodidae) occurring in southern africa.	eighty-three species of ixodid ticks, as well as several entities that have yet to be described, occur in the republic of south africa plus the 4 independent states lying within its borders (bophuthatswana, venda, transkei and ciskei) and in namibia, botswana, lesotho and swaziland. they belong to the following genera: amblyomma (8 spp.); aponomma (3 spp.); boophilus (2 spp.); cosmiomma (1 sp.); dermacentor (1 sp.); haemaphysalis (10 spp.); hyalomma (2 spp., one of them with 2 subspp.); ixodes ( ...	1991	1881661
extensive examination of different tick species for infestation with coxiella burnetii in slovakia.	between 1987-1989 almost 7000 adult ixodes ricinus, dermacentor reticulatus, dermacentor marginatus, haemaphysalis concinna, haemaphysalis punctata and haemaphysalis inermis ticks collected in all 38 districts of slovakia were screened for the presence of coxiella burnettii. the proportion of ticks containing c. burnetii as indicated by the haemocyte test was less than 3%. attempts to recover c. burnetii by inoculation of yolk sacs of embryonated hen eggs from pools of 1-6 specimens of haemocyte ...	1991	1884784
epidemiology of canine babesiosis in relation to the activity of dermacentor reticulatus in southern jura (france).	dates of onset of canine babesiosis within a hyperendemic focus in france (rhone valley, south of jura and north of the alps) were compared to the seasonal population level of the adult stage of dermacentor reticulatus over a 12-month period (december 1982-november 1983). cases of babesiosis occurred in spring and fall when adult d. reticulatus were active. the fluctuations of the vector tick population and the onsets of canine babesiosis were also correlated with climatic changes: no tick activ ...	1991	1893798
ectoparasites from elk (cervus elaphus nelsoni) from wyoming.	hides of nine elk, collected during the winter of 1986-1987 from the national elk refuge, wyoming (usa) were examined for ectoparasites. parasites recovered were mites, psoroptes sp. (five elk); lice, solenopotes ferrisi and bovicola (bovicola) longicornis (seven elk); and winter ticks, dermacentor albipictus (nine elk). three elk with severe scabies had an estimated 0.6 x 10(6), 3.8 x 10(6) and 6.5 x 10(6) mites, respectively. densities of mites were much higher in skin regions with severe derm ...	1991	1920665
[the effect of the physiological age of dermacentor marginatus (ixodidae) ticks on their infection with and the infiltration of the tick-borne encephalitis virus into the saliva].	the decisive effect of physiological age of ticks on the infection of their saliva was revealed by means of parenteral infection of d. marginatus females with tick-borne encephalitis virus. the virus was not found in the saliva of young individuals of instar ii. maximum number of cases of saliva infection was recorded in mature ticks of instar iii (50%). it was established that the infection of saliva did not depend on the amount of virus in the tick's body. less susceptibility to the virus of y ...	1991	1923570
etiologic agent of lyme disease, borrelia burgdorferi, detected in ticks (acari: ixodidae) collected at a focus in alabama.	the study was conducted at sites of known transmission of borrelia burgdorferi in east central alabama. the objectives were to determine species of ticks present at these sites, their host associations, and species of ticks and small mammals naturally infected with b. burgdorferi. a total of 451 hosts were examined for ticks, including cotton mice, peromyscus gossypinus (le conte); cotton rats, sigmodon hispidus say & ord; southern short-tailed shrews, blarina carolinensis (bachman); house mice, ...	1991	1941933
borrelia burgdorferi in ticks (acari: ixodidae) from coastal virginia.	ixodid ticks removed from hosts and from vegetation during march-november 1987 at sites in coastal virginia and north carolina were examined for borrelia burgdorferi. b. burgdorferi was evident in nine (22%) ixodes cookei packard removed from rice rats (oryzomys palustris), a white-footed mouse (peromyscus leucopus), and raccoons (procyon lotor); four (6%) amblyomma americanum (l.) removed from raccoons; and two (3%) dermacentor variabilis (say) removed from a raccoon and a rice rat. b. burgdorf ...	1991	1941936
lyme disease in california: interrelationship of ixodid ticks (acari), rodents, and borrelia burgdorferi.	the association of immature ixodid ticks, several species of rodents, and the lyme disease spirochete, borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner, was studied in two habitats in northern california in spring and summer 1985 and year-round in 1986. a total of 428 rodents were collected from ecotonal chaparral and a woodland-grass-rock outcrop; the former habitat yielded six species, the latter three species. the deer mouse, peromyscus maniculatus (wagner), and the piñon mou ...	1991	1941942
horizontal movement of adult ixodes dammini (acari: ixodidae) attracted to co2-baited traps.	the ability of male and female deer ticks, ixodes dammini spielman, clifford, piesman, & corwin, to move horizontally was evaluated by performing a mark-recapture study. in each of two experiments, 120 ticks were marked with fluorescent powder and released at predetermined distances from a co2-baited trap. the mean recruitment distance was 1.8 m after 6 d of trap operation. this distance is appreciably lower than those calculated from previous studies of several other species of ixodid ticks, in ...	1991	1941943
apparent incompetence of dermacentor variabilis (acari: ixodidae) and fleas (insecta: siphonaptera) as vectors of borrelia burgdorferi in an ixodes dammini endemic area of ontario, canada.	from april to october 1990, white-footed mice, peromyscus leucopus (rafinesque), were examined for ectoparasites on long point, ontario, the only endemic area for ixodes dammini clifford, spielman, piesman & corwin and borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner known in canada. larval and nymphal i. dammini and dermacentor variabilis (packard), and adult fleas orchopeas leucopus (baker), epitedia wenmanni (rothschild), and ctenophthalamus pseudagrytes baker were common on ...	1991	1941949
dermacentor albipictus (acari, ixodidae) on captive reindeer and free-ranging woodland caribou.	infestations of winter ticks (dermacentor albipictus) on two captive reindeer (rangifer tarandus tarandus) are reported and may be associated with increased grooming and alopecia. over 400,000 ticks were recovered from one reindeer. few ticks (less than 25 ticks/animal) were found on three free-ranging woodland caribou (rangifer tarandus caribou).	1990	1974936
longitudinal study of natural foci of central european encephalitis virus in west slovakia.	a total of 2922 small terrestrial mammals of 12 species were collected in six localities of west slovakia between 1981 and 1986. when examined for the prevalence of neutralizing antibodies (na) to central european encephalitis (cee) virus we found that 14.6% had antibody. nearly all (97%) of the 426 animals with antibody were clethrionomys glareolus, the most abundant species (52.6% of mammals collected, 15.1% of those with antibody). apodemus flavicollis (22.5% of mammals collected, 18.1% of th ...	1990	1983180
ehrlichiosis in children.	tick-borne rickettsiae of the genus ehrlichia have recently been recognized as a cause of human illness in the united states. in the years 1986-1988, 10 cases of ehrlichiosis were diagnosed in children in oklahoma. fever and headache were universal: myalgias, nausea, vomiting, and anorexia were also common. rash was observed in six patients but was a prominent finding in only one. leukopenia, lymphopenia, and thrombocytopenia were common laboratory abnormalities. six patients were treated with t ...	1991	1987531
factors v and vii anticoagulant activities in the salivary glands of feeding dermacentor andersoni ticks.	the salivary glands of dermacentor andersoni ticks possess anticoagulant activities that can alter the clotting time of rabbit whole blood. salivary gland extracts from female ticks inhibit both the intrinsic and extrinsic coagulation systems, and maximal activities against both pathways occur when the ticks attain about 250 mg feeding weight. these anticoagulants are directed against both coagulation factors v and vii, but they do not affect factors ii or x. despite this salivary anticoagulant ...	1991	1992089
parasitic and phoretic arthropods of sylvatic and commensal white-footed mice (peromyscus leucopus) in central tennessee, with notes on lyme disease.	sixteen species of parasitic or phoretic arthropods were collected from 56 white-footed mice, peromyscus leucopus, live-trapped in central tennessee from april through november 1987. arthropod infestation was compared for mice taken from sylvatic (woodland) versus commensal (household) habitats. three species were recorded from hosts in both habitats: the sucking louse hoplopleura hesperomydis, the flea epitedia wenmanni, and the laelapid mite androlaelaps casalis. twelve of the 13 remaining art ...	1991	2010854
nonspecific activation of complement factor 5 by isolated dermacentor andersoni salivary antigens.	salivary gland extracts from feeding dermacentor andersoni ticks contain an activity that activated both rabbit and human complement to produce inflammatory cell chemotactic activity. purified salivary antigens (sga), isolated from the glands of female ticks with anti-saliva immunoglobulins from tick-resistant rabbits, also induced chemotactin generation. it has been demonstrated previously that the intradermal injection of such sga into normal animals induces nonspecific inflammatory reactions ...	1991	2010863
ixodid and argasid ticks. keys to their identification.	ticks of the ixodidae family are important ectoparasites of humans and animals. of the 80 or so species found in the united states, about 20 are of veterinary importance. ticks are second only to mosquitoes as carriers of human pathogens. the ixodid (or hard) ticks are the most common and are represented by the genera ixodes, haemaphysalis, boophilus, rhipicephalus, amblyomma, and dermacentor. accurate identification of the species of ixodid ticks within an area is a prerequisite to control and ...	1991	2014622
rocky mountain spotted fever.	rocky mountain spotted fever is an endemic tickborne disease found throughout the united states and other regions of the world. exposure may result in a spectrum of disease from subclinical infection to severe or fatal multiorgan collapse. the disease is maintained in nature in ixodid tick vectors and their hosts. the most important ticks in the united states are dermacentor variabilis and dermacentor andersoni. small mammals are the natural reservoirs in the wild. dogs become infected when a ti ...	1991	2014623
tick information sheet. the american dog tick. dermacentor variabilis.		1991	2014624
tick information sheet. the rocky mountain wood tick. dermacentor andersoni.		1991	2014625
serodiagnostic antibody responses to psoroptes sp. infestations in bighorn sheep.	the antibody responses of bighorn sheep (ovis canadensis) infected with psoroptes sp. mites were investigated by enzyme linked immunosorbent assay on western blots of p. cuniculi antigens. serum from 20 psoroptes sp.-infested bighorn sheep (o. canadensis mexicana, o. canadensis nelsoni, o. canadensis canadensis) from new mexico, nevada, california, and idaho reacted strongly with mite antigens ranging from 12 to 34 kd. serum from 35 psoroptes sp.-free bighorn sheep of unknown tick infestation st ...	1991	2023305
differential effects of photoperiod on development and reproduction in "montane" and "prairie" strains of the rocky mountain wood tick (acari: ixodidae).	progeny of dermacentor andersoni stiles adults collected from one "montane" and two "prairie" sites in southern alberta, canada, were exposed to combinations of 9:15, 11:13 and 13:11 (l:d) daily photoperiods during various stages of their life cycle. time required for developmental and reproductive events was recorded. significant differences in mean molting times of fed larvae were observed, yet the differences were small, and mean times were not attributed to photoperiodic regime. fed nymphal ...	1991	2033610
notes on dermacentor ticks: redescription of d. marginatus with the synonymies of d. niveus and d. daghestanicus (acari: ixodidae).	dermacentor marginatus (sulzer 1776), a distinctive tick of the palearctic faunal region is redescribed from 941 specimens collected throughout its geographical range. the species display a very high intraspecific morphological variation, especially at the level of palpal dorsal spur, size of cornua, spiracular plate, scutal pattern, and female genital aperture, features commonly used in the determination of several species in the subgenus serdjukovia santos dias. however, the relative proportio ...	1991	2033615
determination of vitellogenin titer in the hemolymph of dermacentor variabilis (acarina: ixodidae) using an indirect enzyme-linked immunosorbent assay.	using polyclonal antibodies against dermacentor variabilis (say) egg vitellin, we developed an indirect, competitive enzyme-linked immunosorbent assay (elisa). vitellogenin in the hemolymph of females was quantitatively monitored through feeding (slow feeding and rapid engorgement feeding periods) and postfeeding (preoviposition and oviposition) until death. vitellogenin concentrations in hemolymph ranged from 1 microgram/ml on the first day of feeding to a maximum of 430 micrograms/ml on the th ...	1991	2033618
parasitic and phoretic arthropods of the elephant-eared and the santa cruz kangaroo rats.	the parasitic and phoretic arthropods of the elephant-eared kangaroo rat (dipodomys elephantinus) and santa cruz kangaroo rat (d. venustus) are reported; most of these represent new host records. thirteen of 14 (93%) of d. elephantinus and 11 of 12 (92%) of d. venustus had 11 and nine arthropod species, respectively. larval and nymphal stages of the tick dermacentor occidentalis were the most prevalent parasite (77%) on d. elephantinus whereas the mesostigmatid mite androlaelaps fahrenholzi was ...	1991	2067062
[the possible role of the salivary gland substrate in ixodid ticks as an adjuvant enhancing arbovirus transmission].	using a model: salivary glands of dermacentor ticks--tick-borne encephalitis virus--guinea pig--d. marginatus ticks, it became possible to confirm the data of jones et al. (1989) on the role of a substrate of rhipicephalus appendiculatus glands as a strong enhancer of orthomyxovirus togoto transmission during subcutaneous administration of a moderate virus dose to virus-resistant guinea pig. a tendency was only noticed towards better infectivity of ticks with the administration of sub- or suprao ...	1991	2067469
[one of the developmental dead ends or a method of dispersal of the pasture tick dermacentor marginatus].	accumulation of pasture ticks dermacentor marginatus has been discovered in the wool of sheep, 5-6 cm from the skin surface, the temperature in those sites being permanent 18-20 degrees c. the ticks died either in the course or following ovipositor. it may be assumed that this was followed by the appearance of larvae from oocysts. it is suggested that the above phenomenon is one of the deadlines in dermacentor marginatus development or one of the unusual ways of their larvae habitation on pastur ...	1991	2067499
[babesiosis of dogs in germany: epidemiologic case analysis].	between january 1987 and february 1990 babesia infections were detected in 320 dogs in germany by means of microscopical and/or serological methods. it was found, that 316 dogs were infected with babesia canis and 4 animals with babesia gibsoni. of the babesia-canis-positive dogs 184 were abroad up to 4 months before diagnosis, mainly in france, spain and italy, but also in hungary, greece, jugoslavia, portugal, morocco, togo, pakistan, sri lanka, malaysia, turkey, romania, austria and the nethe ...	1991	2068714
experimental infection of the white-footed mouse with borrelia burgdorferi.	laboratory raised white-footed mice (peromyscus leucopus) were inoculated experimentally with live spirochetes (borrelia burgdorferi), the etiologic agent of lyme disease (borreliosis). prior to inoculation, mouse sera were tested with an indirect fluorescent antibody test, and all mice were seronegative. all inoculated mice seroconverted. in tick transmission studies, immature stages of ixodes dammini and dermacentor variabilis attached and fed to repletion on mice, but only i dammini transferr ...	1990	2085225
stability of dermacentor variabilis populations (acari: ixodidae).		1990	2093615
[the initial experience in using discriminant analysis for differentiating close species of ticks in the genus dermacentor (ixodidae) by the larval phase based on morphometric data].		1990	2100000
serologic survey of selected zoonotic disease agents in black-tailed jack rabbits from western texas.	a serologic survey for the agents of rocky mountain spotted fever (rmsf) (rickettsia rickettsii), borrelia spp. including the causative agent for lyme disease (borrelia burgdorferi), and plague (yersinia pestis) was conducted on blood samples collected from 30 and 46 black-tailed jack rabbits (lepus californicus) from an urban environment in lubbock, texas (usa) during winter 1987 and the following spring 1988, respectively. antibody titers to the agents of rmsf and borreliosis were detected in ...	1990	2106044
survey of ticks (acarina: ixodidae) for crimean haemorrhagic fever virus activity in jammu & kashmir state, india.	a survey of ixodid ticks was carried on in 1977 to determine the crimean haemorrhagic fever (chf) virus activity in jammu & kashmir state, india. in all, 412 immatures and 3258 adults belonging to 7 genera and 16 species of ticks were collected as ectoparasites of small and large mammals. these included one species each of the genera boophilus, dermacentor and nosomma, 2 species of rhipicephalus, 3 species of ixodes and 4 species each of haemaphysalis and hyalomma. haem. bispinosa was the predom ...	1990	2111801
hispid cotton rats (sigmodon hispidus) as a source for infecting immature dermacentor variabilis (acari: ixodidae) with rickettsia rickettsii.	hispid cotton rats (sigmodon hispidus say and ord) were susceptible to infection with rickettsia rickettsii wolbach under laboratory conditions and were capable of serving as sources for infecting ticks with rickettsiae. cotton rats developed rickettsemias that could be detected for as long as 6 h following intraperitoneal inoculation of 10(5) plaque-forming units (pfus) of r. rickettsii (morgan strain). an estimate of the median infectious dose (id50) was made by inoculating six groups (eight a ...	1990	2117665
isolation of bhanja virus in romania.	the presence of bhanja virus was notified for the first time in our country in 1986, by the serological study performed on human and domestic animals sera. in 1988 four bhanja virus strains from dermacentor ticks were isolated in alba and caraş-severin counties. a high percent of domestic animals, originating in this region, presents antibodies to the isolated strains and also to bhanja virus reference strain.	1990	2129278
borrelia burgdorferi in ticks of the canton tessin (switzerland).	in the northern alps it is hard to find an ixodes ricinus population which does not harbour borrelia burgdorferi. the infection rates range from 5 to 34% for adults and nymphs to 3.1% for larvae. this study shows that the infection rates on the southern side of the alps are similar, at 25% for adults, 36.2% for nymphs and 3.2% for larvae. with respect to tick species other than i. ricinus, we did not succeed in finding any spirochetes in dermacentor marginatus, haemaphysalis punctata, ixodes hex ...	1990	2132440