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1.
Abstract A polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) assay developed for identification of five species of the Anopheles minimus Theobald group and a related mosquito species of the Myzomyia Series (Diptera: Culicidae) was applied to morphologically identified adult female specimens collected in Ratanakiri Province, north‐eastern Cambodia. In addition to finding An. aconitus Dönitz, An. minimus species A and An. pampanai Büttiker & Beales, some specimens showed a new restriction banding pattern. Siblings of specimens that exhibited this new PCR‐RFLP pattern were morphologically identified as An. culicifacies James sensu lato. Based on nucleotide sequences of the ribonuclear DNA internal transcribed spacer 2 region (ITS2) and the mitochondrial cytochrome oxidase I gene (COI), these specimens were recognized as An. culicifacies species B (sensu Green & Miles, 1980 ), the first confirmed record of the An. culicifacies complex from Cambodia. This study shows that the PCR‐RFLP assay can detect species not included in the initial set‐up and is capable of identifying at least seven species of the Myzomyia Series, allowing better definition of those malaria vector and non‐vector anophelines in South‐east Asia.  相似文献   

2.
Abstract. Mosquitoes (Diptera: Culicidae) of the Anopheles (Cellia) Myzomyia Series are important malaria vectors in Africa, India and Southeast Asia. Among 10 named species of Myzomyia known from the Oriental Region, seven form the An. minimus group. Even for expert taxonomists, the adults of these species remain difficult to identify morphologically. For technical staff of malaria control programmes, confusion may extend to misidentification of species that are not formally within the minimus group. For identification of specimens from Indochina (Cambodia, Laos, Vietnam), we describe a multiplex polymerase chain reaction (PCR) assay, based on rDNA internal transcribed spacer 2 (ITS2) sequences, that employs a cocktail of primers to identify An. minimus Theobald sibling species A and C (sensu; Green et al., 1990) and three other species in the An. minimus group (An. aconitus Dönitz, An. pampanai Büttiker & Beales, An. varuna Iyengar), as well as An. jeyporiensis James, also belonging to the Myzomyia Series. As the test is DNA‐based, it can be applied to all life stages of these mosquitoes for ecological investigations and vector incrimination studies. This PCR assay is simpler, quicker, cheaper and more readily interpreted than previous assays.  相似文献   

3.
ABSTRACT. Sympatric occurrence of homozygotes for two electro-morphs controlled by a locus for octanol dehydrogenase, and the absence of heterozygotes, at two localities, indicates two isomorphic species within the taxon Anopheles minimus Theobald in Thailand. This view is supported by significant, relative deficiences of heterozygotes at other electromorphic loci. Gene frequency data are reported for seven electro-morphic loci in An.minimus sensu lato from eleven localities: one of the newly recognized species predominated in all but one locality and the second was confined to two localities. This species pair of An.minimus s.l. was clearly distinguished from An.aconitus Donitz, An.pampanai Biittiker & Beales and An.varuna Iyengar, three species closely related to An.minimus s.l. in the series Myzomyia of Anopheles subgenus Cellia.  相似文献   

4.
Malaria is an important public health problem in Thailand, especially along international borders. In this study, we conducted a longitudinal entomological survey in six villages and rubber plantation sites to address the spatio‐temporal abundance and behavior of malaria vectors in Ubon Ratchathani Province along the Thailand‐Laos border. Adult female mosquitoes were collected by human landing collections (indoor and outdoor) and by cattle bait collections twice per year, during rainy and dry seasons. Mosquitoes were morphologically identified and sibling species were determined by allele‐specific PCR. Of the 10,024 Anopheles, 9,328 (93.1%) and 696 (6.9%) were collected during the rainy and dry seasons, respectively. A total of 9,769 (97.5%) and 255 (2.5%) was collected on cattle and human baits, respectively. Very few primary and secondary malaria vectors were collected, consisting of 12 specimens of An. dirus, eight An. minimus, and seven An. aconitus. Of the 152 specimens of the Maculatus Group, only three were identified to An sawadwongporni by molecular methods. The others were 112 An. rampae, a non‐vector, that were not amplified or were misidentified as other non‐vectors. The very low density of primary malaria vectors found in the study villages suggests that entomological risk and malaria transmission is higher in neighboring forest areas. Further studies on malaria vector distribution, as well as human behaviors, are needed to understand malaria transmission dynamics in the province and to develop suitable vector control methods.  相似文献   

5.
Abstract. Among Oriental anopheline mosquitoes (Diptera: Culicidae), several major vectors of forest malaria belong to the group of Anopheles (Cellia) leucosphyrus Dönitz. We have morphologically examined representative material (> 8000 specimens from seven countries) for taxonomic revision of the Leucosphyrus Group. Six new species are here described from adult, pupal and larval stages (with illustrations of immature stages) and formally named as follows: An. latens n. sp. (= An. leucosphyrus species A of Baimai et al., 1988b), An. cracens n. sp., An. scanloni n. sp., An. baimaii n. sp. (formerly An. dirus species B, C, D, respectively), An. mirans n. sp. and An. recens n. sp. Additionally, An. elegans (James) is redescribed and placed in the complex of An. dirus Peyton & Harrison (comprising An. baimaii, An. cracens, An. dirus, An. elegans, An. nemophilous Peyton & Ramalingam, An. scanloni and An. takasagoensis Morishita) of the Leucosphyrus Subgroup, together with An. baisasi Colless and the An. leucosphyrus complex (comprising An. balabacensis Baisas, An. introlatus Baisas, An. latens and An. leucosphyrus). Hence, the former Elegans Subgroup is renamed the Hackeri Subgroup (comprising An. hackeri Edwards, An. pujutensis Colless, An. recens and An. sulawesi Waktoedi). Distribution data and bionomics of the newly defined species are given, based on new material and published records, with discussion of morphological characters for species distinction and implications for ecology and vector roles of such species. Now these and other members of the Leucosphyrus Group are identifiable, it should be possible to clarify the medical importance and distribution of each species. Those already regarded as vectors of human malaria are: An. baimaii[Bangladesh, China (Yunnan), India (Andamans, Assam, Meghalaya, West Bengal), Myanmar, Thailand]; An. latens[Borneo (where it also transmits Bancroftian filariasis), peninsular Malaysia, Thailand]; probably An. cracens (Sumatra, peninsular Malaysia, Thailand); presumably An. scanloni (Thailand); perhaps An. elegans (the Western Ghat form of An. dirus, restricted to peninsular India); but apparently not An. recens (Sumatra) nor An. mirans[Sri Lanka and south-west India (Karnataka, Kerala, Tamil Nadu)], which is a natural vector of simian malarias. Together with typical An. balabacensis, An. dirus and An. leucosphyrus, therefore, the Leucosphyrus Group includes about seven important vectors of forest malaria, plus at least a dozen species of no known medical importance, with differential specific distributions collectively spanning > 5000 km from India to the Philippines.  相似文献   

6.
We determined the species diversity, blood‐feeding behavior, and host preference of Anopheles mosquitoes in two malaria endemic areas of Tak (Mae Sot District) and Mae Hong Son (Sop Moei District) Provinces, located along the Thai border with Myanmar, during a consecutive two‐year period. Anopheline mosquitoes were collected using indoor and outdoor human‐landing captures and outdoor cow‐baited collections. Mosquitoes were initially identified using morphological characters, followed by the appropriate multiplex AS‐PCR assay for the identification of sibling species within Anopheles (Cellia) complexes and groups present. Real‐time PCR was performed for parasite‐specific detection in mosquitoes (Plasmodium spp. and Wuchereria bancrofti). A total of 7,129 Anopheles females were captured, 3,939 from Mae Sot and 3,190 from Sop Moei, with 58.6% and 37% of all anophelines identified as An. minimus, respectively. All three malaria vector complexes were detected in both areas. One species within the Minimus Complex (An. minimus) was present along with two related species in the Funestus Group, (An. aconitus, An. varuna), two species within the Dirus Complex (An. dirus, An. baimaii), and four species within the Maculatus Group (An. maculatus, An. sawadwongporni, An. pseudowillmori, and An. dravidicus). The trophic behavior of An. minimus, An. dirus, An. baimaii, An. maculatus, and An. sawadwongporni are described herein. The highest An. minimus densities were detected from February through April of both years. One specimen of An. minimus from Mae Sot was found positive for Plasmodium vivax.  相似文献   

7.
Malaria has declined around Chilika Lake (85°20′ E, 19°40′ N) in Orissa State, India, from hyperendemicity in the 1930s to hypoendemicity during recent decades. Six decades ago, 21 spp. of Anopheles mosquitoes (Diptera: Culicidae) were recorded from this area, including the well known Indian malaria vectors An. culicifacies Giles, An. fluviatilis James, An. maculatus Theobald, An. stephensi Liston and An. sundaicus (Rodenwaldt), the last formerly regarded as the main vector locally. Surveys of Chilika area during 1995–96 found 8 spp. of culicine plus 14 spp. of anopheline mosquitoes, the latter comprising An. subpictus Grassi sensu lato, An. hyrcanus (Pallas) s.l., An. vagus Dönitz, An. annularis van der Wulp s.l., An. culicifacies Giles s.l., An. aconitus Dönitz, An. varuna Iyengar, An. barbirostris van der Wulp s.l., An. philippinensis Ludlow, An. ramsayi Covell, An. jeyporiensis James, An. pallidus Theobald, An. tessellatus Theobald and An. karwari James in decreasing order of abundance. Among indoor‐resting female mosquitoes, the anthropophilic index was 4–7% and some species (An. culicifacies, An. subpictus, An. vagus) tended to enter houses for resting after blood‐feeding outside. Females of potentially infective age (three‐parous) were obtained for An. culicifacies (11%) and An. annularis (< 2%), the more abundant established vector in this coastal area, but not for small samples of An. subpictus and An. vagus. Anophelines reported previously but not found in our survey were An. fluviatilis, An. jamesii Theobald, A. maculatus, An. splendidus Koidzumi, An. stephensi, An. theobaldi Giles and the former main vector An. sundaicus.  相似文献   

8.
Intra‐ and interspecific molecular variation were investigated in four members of the Minimus Group of Anopheles subgenus Cellia: An. aconitus, An. varuna, An. minimus A and An. minimus C. DNA sequence divergence between these species at a mitochondrial locus (cytochrome oxidase II) and at three nuclear loci (ITS2 and D3 regions of rDNA and guanylate cyclase) is reported. The data confirm the presence of two cryptic species, A and C, within An. minimus and provide evidence for the existence of a third species. Anopheles minimus A and C are estimated to have diverged 0.57–1.5 million years ago. The discrepancy observed using the guanylate cyclase intron, which is the fastest evolving region known in the Gambiae Complex but is relatively slowly evolving in the Minimus Group, is discussed. The long‐term effective population sizes of An. minimus A and C are estimated to be in their millions, with that of species A being approximately twice the size of species C. This implies that An. minimus C has a much wider distribution than currently recognized, with possible widespread implications for vector control. No evidence was found for population structuring in either species A or C: there was greater variation of mitochondrial haplotypes within than among localities. The phylogenetic relationships of Oriental members of the Myzomyia Series are reconstructed.  相似文献   

9.
Abstract Anopheles dirus complex is a major malaria vector in Southeast Asia and South China. Rut the role played by different member of the species complex in malaria transmission is not clearly known. Correct identification of the sibling species is a foundational requirement for working out a sound scheme in mosquito biosystematics. This paper reports the resuets of biosystematic studies on the chromosomal karyotype, egg microstructure, ribosomal DNA sequences of a second internal transcribed spacer region and polymerase chain reactions of the complex in China. Specimens of species A and D from Hainan and Yunnan Provinces were carefully analyzed and the importance of development aspect of the mosquito biosystematics in malaria control is discussed.  相似文献   

10.
Abstract. The phylogenetic relationships of fifteen Oriental and two Afrotropical taxa of the Myzomyia Series of Anopheles subgenus Cellia and two outgroup species, An. maculatus (Neocellia Series) and An. dirus A (Neomyzomyia Series), were inferred from nucleotide sequences of the entire 685 bp of the mitochondrial cytochrome oxidase subunit II locus (COII) and 372 bp of the third domain (D3) of the 28S rDNA locus, both separately and together. Alignment of the D3 sequences was achieved with the aid of secondary structure comparisons, and the pattern of nucleotide substitution was best explained by the GTR + I + G model for either separate or combined datasets. Maximum likelihood and maximum parsimony analyses robustly identified five monophylies: An. fluviatilis U and T; An. fluviatilis U and T + An. minimus A, C, E and #157 + An. leesoni; An. filipinae + An. mangyanus; An. filipinae + An. mangyanus + An. aconitus; and An. culicifacies A and B. The results confirm the specific status of An. flavirostris, the close relationship of An. leesoni with the Minimus Complex, and the exclusion of An. jeyporiensis, An. culicifacies s.l and An. funestus from the Minimus Group. All of the species classified as members of the Minimus Group on morphological grounds formed a single clade, which comprised two subgroups: the Minimus Subgroup, including An. minimus s.l., An. fluviatilis s.l., An. leesoni and An. flavirostris, and the Aconitus Subgroup, including An. filipinae, An. mangyanus, An. aconitus, An. pampanai and An. varuna. However, these clades are only weakly supported by the present dataset.  相似文献   

11.
This study aimed to develop a single-round multiplex PCR method for the identification of Anopheles minimus complex (An. minimus and Anopheles harrisoni) and Anopheles aconitus subgroup (An. aconitus and Anopheles varuna), and for the simultaneous detection of Plasmodium falciparum and Plasmodium vivax in these vectors. Five primers were created for a single-round multiplex PCR assay to identify four anopheline mosquitoes combined with three Plasmodium primers for the detection of P. falciparum and P. vivax in vectors. The four species of anopheline vectors and two Plasmodium species, P. falciparum and P. vivax, could be identified by the combination of eight primers in the single-round multiplex PCR assay. The amplified species-specific products were 380 bp for An. minimus, 180 bp for An. harrisoni, 150 bp for An. aconitus, 310 bp for An. varuna, 276 bp for P. falciparum, and 300 bp for P. vivax. The sensitivities were 0.5 pg/μl (25 sporozoites/μl) for P. falciparum DNA and between 0.5 and 5 pg/μl (25–250 sporozoites/μl) for P. vivax DNA. Furthermore, this developed method could be used to identify field caught An. minimus complex, An. aconitus subgroup from Thailand and Lao PDR. Also, it was successfully used to identify the species An. minimus, An. harrisoni, An. aconitus and An. varuna and to detect and identify P. falciparum and P. vivax in caught anopheline mosquitoes. The sensitivity of this method was high for simultaneous detection of P. falciparum and P. vivax in anopheline mosquitoes.  相似文献   

12.
In Madagascar, Anopheles gambiae has been found below altitudes of 1,000 m. We sampled An. gambiae sensu lato (sl) between 2008 and 2010 in the Central Highlands of Madagascar at altitudes over 1,200 m. The study site consists of rainforest, rainforest edge, and an open savanna biotope. Anopheles gambiae and An. arabiensis, as well as molecular forms of An. gambiae, were identified molecularly. An. gambiae accounted for 26.7% at the edge of the rainforest and 2.3% in the open savanna biotope. One specimen of this species was caught in the forest. An. arabiensis accounted for 66.3% at the edge of the rainforest and 97.7 % in the open savanna biotope. All An. gambiae adults tested belonged to the S molecular form. An. gambiae is present at high altitudes in Madagascar, with a high prevalence at the rainforest edge. Several factors, including the appearance of new favorable biotopes, recolonization after a reduction of indoor vector control, and climate change, may contribute to its distribution. The changing distribution of An. gambiae may have consequences for the distribution and incidence of malaria in the Malagasy Highlands.  相似文献   

13.
The malaria control programme of KwaZulu‐Natal Province, South Africa, includes Mamfene and Mlambo communities. Western‐type houses there are currently sprayed with deltamethrin, whereas traditional houses are sprayed with DDT for malaria control. In 2002, mosquitoes of the Anopheles gambiae complex (Diptera: Culicidae) were collected from DDT‐sprayed houses, by window exit traps, and from man‐baited nets outdoors. Larval collections were also carried out at Mzinweni Pan near Mlambo. Species of the An. gambiae complex were identified by rDNA polymerase chain reaction assay. The majority of samples collected by window trap and baited nets were identified as the malaria vector An. arabiensis Patton, with a few An. merus Dönitz and An. quadriannulatus (Theobald). The larval collections were predominantly An. quadriannulatus with a small number of An. arabiensis. Standard WHO insecticide susceptibility tests using 4% DDT and 0.05% deltamethrin were performed on both wild‐caught females and laboratory‐reared progeny from wild‐caught females. Wild‐caught An. arabiensis samples from window traps gave 63% and 100% mortality 24‐h post‐exposure to DDT or deltamethrin, respectively. Wild‐caught An. arabiensis samples from man‐baited net traps gave 81% mortality 24‐h post‐exposure to DDT. The F1 progeny from 22 An. arabiensis females showed average mortality of 86.5% 24‐h post‐exposure to DDT. Less than 80% mortality was recorded from five of these families. Biochemical analyses of samples from each of the families revealed comparatively high levels of glutathione‐S‐transferases and non‐specific esterases in some families, but without significant correlation to bioassay results. Wild‐caught An. quadriannulatus larvae were reared through to adults and assayed on 4% DDT, giving 47% (n = 36) mortality 24‐h post‐exposure. Finding DDT resistance in the vector An. arabiensis, close to the area where we previously reported pyrethroid‐resistance in the vector An. funestus Giles, indicates an urgent need to develop a strategy of insecticide resistance management for the malaria control programmes of southern Africa.  相似文献   

14.
【背景】褐纹甘蔗象原产于菲律宾,严重危害椰子等棕榈科植物和甘蔗,目前该虫已传入我国台湾、广东、广西和云南,尚未在海南省发生。【方法】为尽早预防该虫传入,本文简要描述了褐纹甘蔗象的生物生态学特性,并运用有害生物危险性分析(PRA)方法,从国内分布情况、潜在的经济危害性、受害寄主的经济重要性、传播扩散的可能性和危险性管理难度等方面对该虫入侵海南的可能性进行了定性和定量分析。【结果】褐纹甘蔗象在海南省的风险评估值R=2.08,属于高风险的林业有害生物,建议将其列入海南省林业检疫性有害生物名单;同时提出了该虫的综合防治措施和建议。【结论与意义】本研究可为尽早制定褐纹甘蔗象防范措施提供参考。  相似文献   

15.
Abstract. The effects of introducing permethrin-impregnated bednets on local populations of the malaria vector mosquitoes Anopheles funestus and the An.gambiae complex was monitored during a randomized controlled trial at Kilifi on the Kenyan coast. Pyrethrum spray collections inside 762 households were conducted between May 1994 and April 1995 after the introduction of bednets in half of the study area. All-night human bait collections were performed in two zones (one control and one intervention) for two nights each month during the same period. PCR identifications of An.gambiae sensu lato showed that proportions of sibling species were An.gambiae sensu stricto > An.merus > An.arabiensis.
Indoor-resting densities of An.gambiae s.l. and the proportion of engorged females decreased significantly in intervention zones as compared to control zones. However, the human blood index and Plasmodium falciparum sporozoite rate remained unaffected. Also vector parous rates were unaltered by the intervention, implying that survival rates of malaria vectors were not affected. The human-biting density of An.gambiae s.l. , the predominant vector, was consistently higher in the intervention zone compared to the control zone, but showed 8% reduction compared to pre-intervention biting rates - versus 94% increase in the control zone.
Bioassay, susceptibility and high-performance liquid chromatography results all indicated that the permethrin content applied to the nets was sufficient to maintain high mortality of susceptible vectors throughout the trial. Increased rates of early outdoor-biting, as opposed to indoor-biting later during the night, were behavioural or vector composition changes associated with this intervention, which would require further monitoring during control programmes employing insecticide-treated bednets.  相似文献   

16.
An annotated list of the species of Folsomia fimetaria group recorded in China is given. The new diagnostics of Folsomia candida sensu lato and sensu stricto are proposed basing on European and Asiatic material. Folsomia postsensilis n. sp. is described from Ningxia and Qinghai Provinces. It is characterized by the combination of posterior position of medial sensilla on abdomen, presence of ocelli and short furca.  相似文献   

17.
Sibling species A and B of Anopheles quadriannulatus (Theobald) are recognized as allopatric members of the Anopheles gambiae Giles complex of Afrotropical mosquitoes (Diptera: Culicidae). Species A represents An. quadriannulatus sensu stricto, widespread in southern Africa, whereas An. quadriannulatus species B occurs in Ethiopia. Because of difficulty of identification, distribution of An. quadriannulatus sensu lato remains poorly known. Cytotaxonomy and the standard DNA polymerase chain reaction (PCR) assay do not distinguish between species A and B of An. quadriannulatus. By optimizing the standard PCR assay (Scott et al., 1993) for identification of members of the An. gambiae complex, we identified two discriminant fragments of 153 bp and 900 bp from DNA of An. quadriannulatus species B, whereas only the 153 bp fragment was amplified for species A from South Africa. This modified PCR assay can therefore be used to distinguish between species A and B of An. quadriannulatus s.l. as well as other members of the An. gambiae complex.  相似文献   

18.
Anopheles fluviatilis andAn. minimus complexes, each comprising of at least three sibling species, are closely related and important malaria vectors in Oriental Region. RecentlyAn. fluviatilis species S, which is a highly efficient malaria vector in India, has been made conspecific withAn. minimus species C (senior synonym) on the basis of homology in 335 base pair nucleotide sequence of D3 domain of 28S ribosomal DNA(rDNA). We examined the conspecificity of these two nominal species by obtaining and analysing the DNA sequences of nuclear ribosomal loci internal transcribed spacer 2 (ITS2) and D2-D3 domain of 28S rDNA (28S-D2/D3) from those ofAn. fluviatilis S andAn. minimus C. We found that the sequences ofAn. fluviatilis S are appreciably different from those ofAn. minimus C with pair-wise distance (Kimura-2-parametre model) of 3.6 and 0.7% for loci ITS2 and 28S-D2/D3, respectively. Pair-wise distance and phylogenetic analyses using ITS2 sequences of members of Minimus and Fluviatilis Complexes revealedthat An. fluviatilis S is distantly related toAn. minimus C as compared to any other members of the Fluviatilis Complex. These findings suggest that the two nominal species,An. fluviatilis S andAn. minimus C, do not merit synonymy. The study also confirms that the reported speciesAn. fluviatilis X is synonym with species S.  相似文献   

19.
A 15‐month bionomic study of Anopheles species was conducted in two ecologically distinct villages (coastal and upland) of Sukabumi District, West Java, Indonesia from June 2006 to September 2007. Mosquitoes were captured using human‐landing collections at both sites. During the study, a total of 17,100 Anopheles mosquitoes comprising 13 Anopheles species were caught: 9,151 at the coastal site and 7,949 at the upland site. Anopheles barbirostris, Anopheles maculatus, and Anopheles vagus were the predominant species caught at the coastal site, and Anopheles aconitus, Anopheles barbirostris, and An. maculatus predominated in the upland site. Overall, species were exophagic at both sites, but there was variation between species. Anopheles aconitus was endophagic at the coastal site, exophagic at the upland site, collected most often in April 2007 and had a peak landing time between 22:00 and 23:00. Anopheles sundaicus was only collected at the coastal site, exophagic, collected most often in October 2006, and had a peak landing time between 19:00 and 20:00. Potential malaria vector species such An. aconitus, An. maculatus, and An. sundaicus were present throughout the year. None of the 7,770 Anopheles tested using CSP‐ELISA were positive for malaria, although the risk for malaria outbreaks in Sukabumi district remains high.  相似文献   

20.
This paper describes two new species, Trypeticus fissirostrum n. sp. from Hainan and Trypeticus yunnanensis n. sp. from Yunnan Provinces, China. Three Trypeticus species having been recorded in the territory of China before this study, their total number in this country has now increased to five. A key to the Chinese species is compiled and given in the text. The type specimens are deposited in Institute of Zoology, Chinese Academy of Sciences.  相似文献   

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