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1.
Abstract A 12-month study of Culicoides in Bulloch County, Georgia, U.S.A., revealed that twelve of 23 ,859 specimens (0.05%) of C.stellifer were intersexes as a result of being parasitized by mermithid nematodes. Of these, eleven had male genitalia and female type antennae and one had female genitalia with male type antennae.  相似文献   

2.
王崇财  陈星恒  谭润谦  虞以新 《四川动物》2012,31(2):283-284,172
2009年在海南霸王岭(19.0°N,109.0°E)的昆虫调查采集中,采获许多蠓类,经分类研究,发现其中有二种库蠓新种,分别命名为霸王岭库蠓Culicoides bawanglingensis Yu,Wang and Chen,sp.nov.和曲囊库蠓Culicoides reduncutheca Yu,Wang and Tan,sp.nov.。这2种库蠓属新种的模式标本珍藏于医学昆虫标本馆(北京丰台东大街20号,100071)。  相似文献   

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This study was carried out in the northeast region of Konya in Turkey, between April and December 2004, to determine the vertical distribution of Culicoides (Diptera: Ceratopogonidae) larvae and pupae. Larvae and pupae were collected using the saturated sugar flotation technique in mud samples taken from a range of depths of up to 20 cm. In total, 282 adult Culicoides were obtained. The number of larvae and pupae decreased as the depth increased; at 2.5 cm, 97 Culicoides larvae and 73 Culicoides pupae were found. Larvae and pupae of C. nubeculosus (Meigen) and C. puncticollis (Becker) were mostly found in organic matter-rich breeding sites, while larvae and pupae of C. gejgelensis Dzhafarov and C. festivipennis Kieffer were mostly found in organic matter-poor breeding sites. Culicoides larvae and pupae were obtained largely in July and August.  相似文献   

5.
Abstract. Culicoides variipennis sonorensis females were fed bluetongue virus serotype 11 mixed in sheep blood and were held at constant temperatures of 32, 27, 21 and 15oC. Virogenesis, as measured by enzyme-linked immunosorbent assay (ELISA), proceeded significantly faster at higher temperatures. Based on ELISA absorbance ≥0.2, some flies first were categorized as infected after 1 day, 2 days and 4 days at 32, 27 and 21oC, respectively. Peak levels of virus antigen were seen after 5–7, 7–13 and 18–22 days for flies held at 32, 27 and 21oC, respectively. There was no significant virus replication in flies held at 15oC for 22 days, but latent virus replicated and was detected easily (44% infection) 4–10 days after these flies were transferred to 27oC. The implications for temperature effects on bluetongue epizootiology are discussed.  相似文献   

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黑龙江省库蠓属屋室亚属一新种(双翅目:蠓科)   总被引:9,自引:0,他引:9  
报道采自黑龙江省库蠓属屋室亚属一新种;无齿库蠓Culicoides(Oecacta)un-dentaris,sp.nov,模式标本保存于沈阳军区军事医学研究所。  相似文献   

8.
Abstract. We investigated the identity and distribution of members of the Culicoides variipennis complex in the six New England states of the U.S.A., a region where bluetongue transmission has not been detected. Analyses of seven polymorphic isozyme-encoding loci showed that only C.v.variipennis , not considered to be a vector of the bluetongue viruses, was present. The populations of C.v.variipennis were significantly more hetero-zygous than C.v.sonorensis and Cv.occidentalis populations from similar studies in the state of California. Estimates of genetic diversity among populations of C.v.variipennis in New England were similar to C.v.sonorensis in the state of Colorado, but were significantly more genetically divergent than California populations of Cv.occidentalis. The impact of these findings on the status of New England as a possible bluetongue-free region for the purpose of international trade in ruminant livestock and their germplasm is discussed.  相似文献   

9.
The miracidia of four human blood flukes, Schistosoma haematobium, S. intercalatum, S. mansoni and S. japonicum, have been studied by means of the scanning electron microscope (SEM). Differences have been observed in their respective dimensions, in the configuration of their terebratoria (apical papillae), in the shape of the epidermal plates, and in the distribution of the sensory receptors. The most evident differences have been noticed on the terebratoria where two main patterns of organization of the anastomosing membrane foldings have been described: (1) a ‘rosette’ pattern observed in S. haematobium and S. intercalatum and (2) a ‘honeycomb’ pattern in S. mansoni and S. japonicum. The structure and the taxonomic importance of these morphological features are analysed.  相似文献   

10.
Wing pattern is very important in the taxonomy of the genus Culicoides. To date no quantitative method has been described permitting the inclusion of wing pattern characters with traditional morphometric characters in multivariate studies.
Two alternative methods for quantifying wing pattern are developed here. The first superimposes a grid onto a wing and the 420 'characters' generated are scanned for pigmentation. A second method recognizes 13 pattern elements from a sequentially arranged series of wings. The latter method was considered superior for several reasons: it uses logically acceptable characters, reduces character redundancy and allows easier and faster coding.
Empirical multivariate studies show the pattern element method to be of taxonomic value in the difficult C. pulicaris group, and to have considerable potential for use in this and other groups of Diptera with patterned wings.  相似文献   

11.
Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) play important roles in the transmission of viral diseases affecting wild and domestic ruminants and horses, including Bluetongue (BT) and African horse sickness (AHS) respectively. In southern Europe, BT has been largely transmitted by the classical Afro-Asian vector Culicoides imicola Kieffer. However, other species such as C. obsoletus Meigen, C. scoticus Downs & Kettle and C. pulicaris Linné may also be involved in BTV transmission. As a consequence of the discovery of C. imicola followed by BTV-2 outbreaks on the island of Corsica in October 2000, further studies on these biting midges have been carried out. To better characterize the evolution and phylogenetic relations of Culicoides, molecular analysis in parallel with a morphology-based taxonomic approach were performed. Phylogenetic analyses of French Culicoides species were undertaken using the ribosomal DNA (rDNA) internal transcribed spacer 1 (ITS1) as a molecular target. This region was shown to be useful in understanding evolutionary and genetic relationships between species. Construction of several trees showed that molecular phylogeny within the genus Culicoides correlates not only with morphological-based taxonomy but also with ecological patterns.  相似文献   

12.
Abstract. Data on Culicoides imicola were obtained during studies carried out during the recent outbreak of African horse sickness in Portugal. The previous most northerly published record of C.imicola in Portugal was 38o40'N (Pégöes). In the present work the geographical distribution of this species is extended to the parallel of 41o17'N. We have also confirmed the continuous presence of adult C.imicola in Southern Portugal (Alentejo and Algarve) throughout the year. In the laboratory we obtained this species from a sample of cattle faeces and from another of soil contaminated with animal excreta. In relation to host association 57.37% of C.imicola were trapped in the vicinity of pigsties. Finally, we collected 11 ,463 Culicoides of which 12.47% were C. imicola.  相似文献   

13.
Abstract. An indirect enzyme-linked immunosorbent assay (ELISA) has been developed to identify the bloodmeal sources of Culicoides impunctatus Goetghebuer. Nightly light trapping in Scotland, between April and September 1992, caught a total of 344 blood-engorged female C. impunctatus , all in May, June and July. The insects were stored in 70% ethanol and tested 5–7 months later. Bloodmeal sources were positively identified for 246 (71.5%). Bovine hosts were most common (38.4%), followed by deer (23.0%) and sheep (9.9%). Only one midge had fed on human blood. Relatively freshly fed (<24h), fully engorged females gave the clearest results. The wider applications of the technique to the study of Culicoides host preferences is discussed.  相似文献   

14.
Abstract The hourly flight periodicity of adults of the biting midge Culicoides impunctatus was sampled at a site in Western Scotland, using suction traps over 18 days in July/August 1994. In addition, meteorological conditions were logged continuously. Female but not male C. impunctatus had a bimodal pattern of activity, with peaks at dawn and dusk. The dawn peak (05.00–07.00 hours) was most distinct. Correlation analysis revealed significantly positive relationships between catches of female midges and both relative humidity and rainfall, and negative relationships with wind velocity. The calculation of partial correlation coefficients reinforced the influence of relative humidity on female activity, and highlighted a further positive relationship with air temperature. Male C.impunctatus activity was negatively correlated with air temperature, although the total male catch was relatively small (15% of total trap catches) and further data would be required to confirm this result. Overall, the results help to clarify previous confusion as to whether C.impunctatus has a circadian rhythm of activity, with the data matching closely predictions of a bimodal pattern. Clearly, this pattern will be damped by meteorological conditions, which may vary greatly on a local scale.  相似文献   

15.
Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) may transmit several arboviruses to ruminant livestock. The species of the Obsoletus group are considered to be among the most important vectors of bluetongue virus (BTV) in northern Europe. As agricultural environments offer suitable habitats for the development of their immature stages, the emergence of adult Culicoides from potential breeding sites was investigated at 20 cattle farms throughout Germany in 2012 and 2013. In analyses of species‐specific habitat preferences and relationships between Culicoides abundance in breeding substrates and their physicochemical characteristics, dungheaps emerged as the most important substrate for the development of Culicoides obsoletus sensu stricto (s.s.) (Meigen), whereas Culicoides chiopterus (Meigen) and Culicoides dewulfi Goetghebuer were generally restricted to cowpats. A decreasing pH value was associated with a higher abundance or a higher probability of observing these three species. Furthermore, the abundance of C. obsoletus s.s. was positively related to increasing moisture. Dungheaps were very productive breeding sites for this species and are therefore suggested as a target for potential control measures.  相似文献   

16.
Females of a new water mite species of the genus Hygrobates (Acari, Hydrachnidia, Hygrobatidae) were found to parasitize Pachytriton labiatus (Unterstein, 1930) (Amphibia, Salamandridae), a newt species from S China. Obviously, their particularly modified mouthparts are an adaptation for penetrating the amphibian skin. These data provide the first record of an adult water mite parasitizing a vertebrate host.  相似文献   

17.
四种补血草属植物叶片泌盐结构的扫描电镜观察   总被引:9,自引:1,他引:9  
周玲玲  刘萍  陆嘉惠 《植物研究》2006,26(6):667-671
利用扫描电镜技术,对4种补血草属植物大叶补血草(Limonium gmelinii (Willd.) Kuntze)、耳叶补血草(Limoniu otolepis (Schrenk) Kuntze)、繁枝补血草(Limonium myrianthum (Schrenk) Kuntze)和簇枝补血草(Limonium auream)的叶表面进行了研究,以探讨植物微形态结构与生态环境的关系。结果表明,这4种植物的上下表皮都分布有盐腺,且上表皮的盐腺密度大于下表皮,盐腺的基本结构相同,多由20个细胞构成,其中4个分泌细胞顶端的角质层中央有一小孔,植物体靠盐腺的泌盐孔泌盐。但4种植物在盐腺的密度、盐腺的大小、盐腺与周围表皮细胞的位置等方面存在差异。植物在对盐碱生境的长期适应过程中,促使其强烈地分化出泌盐结构,因而,具有明显的生态适应性。  相似文献   

18.
The three-dimensional organization of the eye lenses of the chicken, the canary, the song-thrush and the kestrel was studied using light and scanning electron microscopy. The lenses of birds are characterized by the presence of two distinct compartments: the annular pad and the main lens body, separated by a cavum lenticuli. The annular pad fibers had a hexagonal circumference all contained a round nucleus and except for the canary were smooth-surfaced and lacking anchoring devices. In the canary, however, the annular pad fibers were studded with edge protrusions and ball-and-socket junctions. The semicircular main lens body fibers of all four species were studded with ball-and-socket junctions and edge protrusions. In contrast with mammals these anchoring devices were present throughout the lens up to the embryonal nucleus. Superficially the main lens body fibers were extremely flat. Additionally membrane elevations and depressions and globular elements were found on these central fibers in three species, the kestrel being the exception. At the transition between annular pad and main lens body the fibers turned their course and the nuclei became oval and disappeared in the deeper aspect of the main lens body. The cavum lenticuli was filled with globules tied off from the annular pad fibers. It seems attractive to assume that the presence of a separated annular pad, a cavum lenticuli filled with globular elements, the extreme flatness of the superficial central fibers and the studding of these central fibers with anchoring devices up to the embryonal nucleus are morphological expressions of the mouldability of the bird's eye lenses and consequently would explain their efficient accommodative mechanism including formation of a lenticonus. The presence of nuclei in the annular pad fibers and their typical change at the transitional zone between annular pad and main lens body are suggestive for a two-phased differentiation in bird's lens fibers: differentiation of the germinative epithelial cells to annular pad fibers which migrate to the main lens body after which they differentiate further to main lens body fibers.  相似文献   

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20.
The ultramorphology of the antennae and mouthparts of the adult Loxocephala perpunctata Jacobi was studied through a scanning electron microscope. Seven types of sensilla were found on antennomeres, including a Böhm bristle on the scape, sensillum trichoideum and plaque organ on the pedicel, two subtypes of sensilla chaetica and two subtypes of sensilla campaniformia on these two antennomeres; and Bourgoin's organ with sensory pegs and sensilla basiconicum on the basal bulb of the flagellum. The mouthparts of L. perpunctata are of the typical piercing-sucking type, similar to mouthparts found in other hemipteran insects. In general, six types of sensilla (i.e., four subtypes of sensilla chaetica, sensillum basiconicum, subapical labial sensillum, uniporous peg-like sensillum, multiporous peg-like sensillum and two subtypes of bristle-like sensilla) were detected on different locations of the labium, with the last three, and numerous cuticular processes, present on the labial tip. The potential functions of these sensilla are discussed.  相似文献   

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