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1.
窄手蚋 (Simulium (Simulium) omorii)是Takahasi(1942)发表的新种,当时放在短蚋属(Omiadag),该蚋标本是采自我国黑龙江省.Takahasi 仅描述了两性成虫和蛹,缺幼虫,况前者也不甚详细 1983年,虞以新和安继尧在我国黑龙江省饶河县珍宝岛地区,采到窄手蚋的两性成虫、幼虫和蛹,描述于后供同道者参考.窄手蚋与Rubzov(1956)描述的S. (S.) tenuimanus Enderlein, 1920很近似,不同的是:1. 足色:雌虫,窄手蚋前、中足股节黑色,后足股节基段1/5棕黄色.tenuimanus蚋,前、中、后足股节巧克力棕黑色,仅基部有点黄色.雄虫,窄手蚋后足转节、股节基端部、胫节基端部和中足基节1/2棕黄色,而tenuimanus 除前足基节和后足胫节基部褐色外,余部黑色.2. 窄手蚋中骨圆形或弹头形,前端圆形,后端凹入呈八字形 tenuimanu 中骨箭形,末端尖.标本保存于军事医学科学院医学昆虫标本馆.  相似文献   

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Ivermectin was injected into hosts and evaluated for effectiveness against the argasid tick Ornithodoros parkeri (Cooley) and the chicken mite Dermanyssus gallinae (DeGeer). O. parkeri second stage nymphs (N2s) showed a marked increase in mortality when fed on mice injected intraperitoneally with ivermectin at a dose between 0.1 and 0.2 mg/kg host body weight. For adult O. parkeri and D. gallinae, 0.4 and 0.5 mg, respectively, per kilogram of host body weight were necessary for an increase in mortality over controls. These latter findings are comparable to those reported for other tick species but differ from those reported for the northern fowl mite, Ornithonyssus sylviarum (Canestrini & Fanzago). Further testing narrowed the effective dose range for O. parkeri adults to between 0.425 and 0.450 mg/kg host body weight. The time interval (4, 8, and 24 h) between ivermectin injection of the host and tick feeding had only a slight influence on the overall effectiveness of the drug. In O. parkeri, doses of 0.0125 to 0.1000 mg/kg body weight did not affect fecundity, hatchability, gross morphology of the reproductive system and synganglion, or histology of the reproductive system. Contrary to reports of irreversibility of effects of ivermectin on gamma aminobutyric acid-mediated neurotransmission, many ivermectin-paralyzed ticks recovered partial mobility over time.  相似文献   

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Forty specimens of Haemulon sciurus were examined for endoparasites and this paper refers to the recovered Nematodes and Acanthocephalans. Aspiculuris tetraptera is for the first time referred in fish and Dollfusentis chandleri is recorded in Brazil and in a new host.  相似文献   

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American canine hepatozoonosis (ACH) caused by Hepatozoon americanum Vincent-Johnson, Macintire, Lindsay, Lenz, Baneth, and Shkap is an emerging, often fatal, tick-borne protozoal disease of dogs in the United States of America. Dogs acquire infection by ingesting ticks that contain oocysts. To understand the invertebrate (definitive) host range of H. americanum, experiments were carried out using four ixodids, Rhipicephalus sanguineus (Latreille), Dermacentor variabilis Say, Amblyomma americanum (L.), and Amblyomma maculatum Koch. Laboratory-reared nymphal ticks were fed on dogs that were either naturally or experimentally infected with H. americanum; when these ticks molted to the adult stage they were either fed to susceptible dogs or were dissected and examined for the presence of oocysts. Mature H. americanum oocysts were found in >90% of A. maculatum (both males and females), whereas oocysts were not found in any of the other three species. These results confirm that A. maculatum is an excellent host and vector for H. americanum and also suggest that this apicomplexan may have a narrow invertebrate host range, at least among ixodid ticks that are likely candidate vectors in the United States.  相似文献   

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The laboratory biology of Ornithodoros (Alectorobius) puertoricensis Fox was studied over a 2-yr period. Approximately 100-150 ticks were reared individually at each of four temperatures: 22, 27, 33, and 40 degrees C and 90-95% RH. The mean egg incubation periods at those temperatures were 20.3, 11.1, 7.3, and 6.1 d, respectively. The average larval feeding period was 5.8 +/- 1.5 d for 15,875 larvae that fed on guinea pigs. The development times for first to fourth nymphal instars were as follows: 11.7, 48.5, 75.1, and 92.1 d, respectively, at 22 degrees C; 5.8, 18.8, 38.0, and 36.0 d, respectively, at 27 degrees C; 4.2, 10.5, 14.9, and 38.1 d, respectively, at 33 degrees C; and 5.8, 10.7, 21.2, and 35.3 d, respectively, at 40 degrees C. Males usually eclosed after three or four molts, and females usually eclosed after four or five molts. Approximately 10% of all nymphs required more than one blood meal per instar at least once during development. Twenty pairs of adults were held at each of three temperatures (22, 27, and 33 degrees C) for a year to study reproductive behavior. The number of gonotrophic cycles per female per year was 6.9, 9.8, and 10.8 at 22, 27, and 33 degrees C, respectively. The mean duration of the gonotrophic cycle was 42.3 d at 22 degrees C, 25.5 d at 27 degrees C, and 20.5 d at 33 degrees C. Mean egg production per female per gonotrophic cycle was 151 at 22 degrees C, 117 at 27 degrees C, and 130 at 33 degrees C and was not affected by temperature. O. puertoricensis did not exhibit autogeny or parthenogenesis. Hyperparasitism was observed in immatures and adults.  相似文献   

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To date there is no report on mosquitoes infected with free-living amoebae. For this reason, the aim of this study was to verify if Aedes aegypti could be susceptible to Acanthamoeba polyphaga under laboratory conditions, so trophozoites were offered as a unique food resource for larvae of first instar. The results show that those amoebae are able to infect and colonize the mosquito gut and could be re-isolated of all stages of the mosquito (larvae, pupae, and adults).  相似文献   

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We examined four species of Plectropomus Oken, 1817 (Serranidae: Epinephelinae), Plectropomus areolatus (Rüppell), Plectropomus laevis (Lacepède), Plectropomus leopardus (Lacepède) and Plectropomus maculatus (Bloch) from sites off Heron Island and Lizard Island on the Great Barrier Reef, Australia (GBR), and the Gambier Islands, French Polynesia. Three new species of Neidhartia Nagaty, 1937, five new species of Prosorhynchus Odhner, 1905, and one previously described species, Prosorhynchus freitasi Nagaty, 1937, are characterised. The three species of Neidhartia, Neidhartia haywardi n. sp., Neidhartia plectropomi n. sp. and Neidhartia tyleri n. sp. are readily distinguishable morphologically. Two of the six species of Prosorhynchus (Prosorhynchus lesteri n. sp. and Prosorhynchus wrightae n. sp.) are easily distinguished from their other congeners by morphology but the other four species (P. freitasi, Prosorhynchus heronensis n. sp., Prosorhynchus munozae n. sp. and Prosorhynchus plectropomi n. sp.) are generally similar in morphology and were only distinguished initially by comparing their ITS2 rRNA sequences. Three additional taxa, one from the GBR and two from French Polynesia, were recognised as distinct on the basis that their ITS2 rRNA sequences differed from those of the new taxa described here; these species remain unnamed for the present. Inter-specific divergence observed within these genera in the ITS2 rRNA ranged from 10 to 42 base pairs (4–16 %) for species of Neidhartia and 2–57 base pairs (3–21 %) for species of Prosorhynchus. Inter-generic divergences were 42–55 base pairs (17–21 %). No intraspecific variation in the ITS2 rRNA region was observed for any of the six species for which multiple sequence replicates were obtained. Phylogenetic analysis of 12 operational taxa from Plectropomus together with sequences of three other species from epinepheline serranids demonstrated that Neidhartia and Prosorhynchus were reciprocally monophyletic with the exception that P. wrightae n. sp. fell either within or basal to the Neidhartia species. The richness of bucephalids in species of Plectropomus appears to be exceptional within the Serranidae relative to that observed in other serranid genera in the tropical Indo-West Pacific.  相似文献   

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The house fly (Musca domestica L.) may transmit Campylobacter to broiler flocks. We assessed the retention time of house flies for Campylobacter jejuni at five temperatures and three doses. Flies were inoculated individually at their proboscis with 1.6 x 10(7) CFU (colony forming units) of C. jejuni and incubated at 15, 20, 25, 30, and 35 degrees C. Furthermore, a dose experiment was conducted at 25 degrees C where individual flies were inoculated in three series: 6.5 x 10(6), 6.0 x 10(4), and 8.2 x 10(2) C.jejuni CFU. Whole flies were tested for C. jejuni carriage at 0, 6, 12, 18, and 24 h by initial preenrichment in Bolton broth, which afterwards was streaked on modified mCCDA agar plates and incubated under micro-aerobic conditions. The results showed that the time C. jejuni remained in flies declined over time with ascending temperatures and when reducing the inoculation dose. All flies stayed Campylobacter positive 24 h postinoculation at 15 degrees C whereas only one-third of the flies were positive at 20 degrees C and few to none at 25, 30, and 35 degrees C. When combinations of temperature and retention time were expressed as accumulated day-degrees, data could be adequately fitted using a generalized linear mixed model that included a linear effect of day-degrees and the difference between the lowest and the two highest doses. Based on model predictions of selected combinations of temperature and dose, the time for 50% and 1% of flies containing Campylobacter was calculated. It is suggested that house flies are mainly short distance carriers of C. jejuni.  相似文献   

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Serratia marcescens Bizio, a facultative pathogen of insects, was isolated from stable flies, Stomoxys calcitrans (L.), collected from Nebraska beef cattle feedlots and dairies. Infection rates in laboratory-reared stable flies infected by topical exposures to the bacterium were 57 and 64% in two experiments. Per os exposures to sucrose and water solutions, and bovine blood inoculated with S. marcescens, produced mortality rates of about 45 and 10%, respectively.  相似文献   

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The literature describing the biocompatibility of glass-poly(alkenoate) ('Glass-Ionomer') cements has been reviewed. This literature shows that these materials have generally good biocompatibility for both dental and orthopaedic use, this latter observation being very recent. There have, though, been a few reports showing that in certain circumstances these materials may cause pulpal irritation and the reasons for these particular findings are considered. Following discussion of the biocompatibility of Glass-Ionomer cements, consideration is given to the likely underlying causes of this feature. Three factors are identified as contributing to the biocompatibility of these cements. They are: (i) minimal exotherm on setting; (ii) rapid neutralization following mixing; and (iii) slow release of ions which are generally biologically beneficial or, at least, benign. This last point is considered in some detail. Previous studies of leaching of ions from Glass-Ionomer cements have shown that only inorganic species are released. The biological effects of each of these inorganic ions are described and their influence on biocompatibility discussed.  相似文献   

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The ultrastructure of the camallanid nematode Procamallanus (Spirocamallanus) halitrophus, a parasite of flounder, is described for the first time by the use of transmission electron microscopy. The body wall is composed of an outer cuticle, a hypodermis, and a muscular layer. The cuticle comprises the epicuticle, the cortical, median, fibrous, and basal layers. The cortical layer is subdivided into an outer zone and an inner zone; the median layer is subdivided into an outer layer, rich in electrondense fibrils, and an inner layer, which does not contain these fibrils; the fibrous layer is subdivided into three regions delimited by electrondense lines; the basal layer presents electrondense sustaining structures. Underlying the basal layer is the hypodermis where many organelles are observed. The musculature is striated, and each muscle cell consists of individualized contractile and noncontractile regions. Inclusion bodies are present in the muscle fibers, hypodermis, hypodermal chord, and in the intestine.  相似文献   

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