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1.
Anopheles halophylus n.sp. is described from Central Brazil. It is distinguished from An. triannulatus (Neiva and Pinto) by morphological and morphometric characters, especially in the male genitalia, larva and egg. Illustrations of the male and female genitalia, egg, larva and pupa, and discussion of the status of names associated with An. triannulatus are provided.  相似文献   

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ABSTRACT. The Anopheles marshallii group of mosquitoes consists of four chromosomally typed species of which three have already been described and named. The fourth chromosomal species, formally known as species E, is described here as Anopheles kosiensis from Kosi Bay, Zululand, South Africa. A photograph of the X chromosome is given. The taxonomic status of Anopheles pitchfordi , a synonym of marshallii , is discussed.  相似文献   

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记述采自云南思茅市水塘内按蚊1新种,讨论了新种与近缘种的鉴别特征。模式标本保存于云南省寄生虫病防治所。  相似文献   

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Abstract Examination of the polytene chromosomes of the fourth instar larvae provides evidence for the existence of two sibling species within the taxon Anopheles (Anopheles) coustani Laveran. Crosses between the two chromosomal types produces sterile male offspring. Since no classical morphological differences can be demonstrated in the adults, the probable existence of such characters in the larvae and pupae is discussed.  相似文献   

7.
This study deals with five species of the Barbirostris Complex of Anopheles subgenus Anopheles that are known to occur in Thailand. Three new species of the complex, A nopheles dissidens sp. nov. , A nopheles saeungae sp. nov. , and A nopheles wejchoochotei sp. nov. , are characterized and compared with Anopheles barbirostris van der Wulp and Anopheles campestris Reid based on specimens of molecularly identified progeny broods. For practical purposes, the five species are essentially isomorphic and can only be unequivocally identified from diagnostic mitochondrial and ribosomal DNA sequences. Based on overall morphological similarity, An. campestris is considered to be a member of the Barbirostris Complex rather than a separate member of the Barbirostris Subgroup. The molecular data, mitotic karyotypes, bionomics, and distributions of the species are reviewed and discussed. It is concluded that integrated molecular epidemiological studies of the complex throughout the Oriental Region are needed to unambiguously elucidate the individual species and their relation to disease. © 2015 The Linnean Society of London  相似文献   

8.
Allozyme variability was analyzed at 16 loci in 11 lines of Anopheles stephensi Liston from Pakistan. Six lines were considered as samples from natural populations. For these lines the mean number of alleles was 1.31-1.63, the degree of polymorphism was 0.188-0.375, the observed heterozygosity was 0.065-0.086, and the genetic distance ranged from 0.001 to 0.016. No population-specific alleles were found. Interbreeding was considerable (mean Fit = 0.183). Differences in allele frequencies were due considerable (mean Fit = 0.183). Differences in allele frequencies were due primarily to local inbreeding (Fis greater than Fst at most loci). The Lahore line, reared for more than 20 generations, had more homozygotes than the other lines. A line refractory to Plasmodium falciparum and a genetic sexing line exhibited decreased allozyme variability. The latter line showed reduced staining intensity at 10 loci. Linkage studies are recommended for the following loci with rare alleles: Acp, Gapdh, Icd-1, Icd-2, Mpi, and Pgd.  相似文献   

9.
Mosquitoes of the Anopheles maculipennis complex were collected in nine provinces of Iran (Esfahan, Fars, Gilan, Golestan, Kohkiluyeh va Boyerahmad, Mazandaran, Tehran, Azarbaijan-e Gharbi and Zanjan) between June 1983 and September 2002. The nuclear rDNA ITS2 sequences of 86 specimens were compared with those of seven species of the complex available in GenBank. Three genetically distinct species of the complex were distinguished: A. maculipennis Meigen, A. sacharovi Favre and a previously unrecognized species. The last species is most similar to, but clearly distinct from, A. martinius Shingarev and A. sacharovi. The taxonomy of A. martinius and A. sacharovi is critically reviewed, and justification is provided for formally recognizing the third species as Anopheles persiensis sp.n. The new species is the first culicid to be characterized and named principally on the basis of DNA evidence. Anopheles persiensis was collected only in the northern Caspian Sea littoral provinces of Gilan and Mazandaran, and it seems likely that this species could be responsible for malaria transmission in this region that was previously attributed to A. maculipennis. A species-specific RFLP-PCR assay based on ITS2 sequences was developed to facilitate further studies of the three species in Iran.  相似文献   

10.
Four satellite DNAs in the Anopheles stephensi genome have been defined on the basis of their banding properties in Hoechst 33258-CsCl density gradients. Two of these satellites, satellites I and II, are visible on neutral CsCl density gradients as a light density peak forming approximately 15% of total cellular DNA. Hoechst-CsCl density gradient profiles of DNA extracted from polytene tissues indicates that these satellites are underreplicated in larval salivary gland cells and adult female Malpighian tubules and possibly also in ovarian nurse cells. The chromosomal location of satellite I on mitotic and polytene chromosomes has been determined by in situ hybridisation. Sequences complementary to satellite I are present in approximately equal amounts on a heterochromatic arm of the X and Y chromosomes and are also present, in smaller amounts, at the centromere of chromosome 3. A quantitative analysis of the in situ hybridisation experiments indicates that sequences complementary to satellite I at these two sites differ in their replicative behaviour during polytenisation: heterosomal satellite I sequences are under-replicated relative to chromosome 3 sequences in polytene larval salivary gland and ovarian nurse cell nuclei.  相似文献   

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Anopheles darlingi is an important vector of human malaria in the Amazon. Adult females of this mosquito species require a blood meal to develop eggs, preferring humans to other blood sources. Although gonotrophic concordance has been described as the norm for An. darlingi, here we report An. darlingi female mosquitoes taking two or more blood meals within their first gonotrophic cycle. Only half of field‐captured adult females fed one blood meal developed follicles to Christophers' stage V. This outcome is dependent on larval nutrition, as 88% of laboratory‐raised well‐nourished females completed the first gonotrophic cycle with only one blood meal, while less nourished females needed additional blood meals. Half of the field‐captured blood‐seeking An. darlingi females had follicles in intermediate (IIIa and IIIb) and final (V) stages of the gonotrophic cycle, supporting the conclusion that An. darlingi blood feed more than once during a gonotrophic cycle. Additionally, we observed females attempting to blood feed a second time during the same day. Additional studies of An. darlingi biting behavior are necessary to accurately estimate Plasmodium sp. entomologic inoculation rates throughout the An. darlingi vast geographical distribution.  相似文献   

12.
Anopheles sundaicus species A of the Southeast Asian A. sundaicus complex is formally named Anopheles epiroticus Linton & Harbach based on DNA sequence differentiation of the whole nuclear ITS2 region and a portion of both the cytochrome b and cytochrome c oxidase I mitochondrial genes. Detailed comparative morphological studies of the adult, larval and pupal stages did not reveal any differential or diagnostic differences that reliably distinguish A. epiroticus from A. sundaicus s.s. Information is provided on the bionomics and systematics of the new species.  相似文献   

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Anopheles (Nyssorhynchus) albitarsis sensu lato is an important malaria vector in Brazil, especially in the Brazilian Amazon region. Chromosome preparations of fourth-instar larvae of A. albitarsis from Iranduba and Coari (AM) and Ilha Comprida (SP) were analyzed for karyotype determination and to improve cytogenetic identification of this species. Anopheles albitarsis possesses 2n = 6 chromosomes, with two pairs (submetacentric and metacentric) of autosomes and one pair of sex chromosomes, with X-Y dimorphism. The sex pair is homomorphic and acrocentric in females and heteromorphic in males, with a punctiform Y chromosome. Somatic pairing was detected in the prometaphase and metaphase chromosomes of the three A. albitarsis populations. Apparently, sex chromosome evolution in the Culicidae does not function as does evolution in the Culicidae, since it occurs in the subfamily Anophelinae, which possesses heteromorphic sex chromosomes and is regarded as primitive, based on several criteria. These karyotype data on the albitarsis complex reinforce the hypothesis that sex chromosome evolution in the subfamily Anophelinae is conserved, and the variation revealed in the mean size of chromosomes in three populations indicates that selective pressure in these populations is occurring only at a genetic level.  相似文献   

15.
Two largely independent studies of chromosomes from natural populations of Anopheles maculatus provide evidence for several genetic species within the taxon. (1) Polytene chromosome variation shows four different rearrangements of arm 2 and three rearrangements of the X chromosome. There is strong evidence for three species. Two allopatric populations represent either dramatic geographic variation for two independent inversion systems within one of the genetic species, or represent two additional species. Their species status remains unresolved by this work. (2) Heterochromatic variation occurs in both X and Y chromosomes as revealed by Giemsa-banding of mitotic chromosomes from larval brains. The distribution and association of these various sex chromosomes give further evidence of a species complex. A preliminary correlation of these two kinds of chromosomal variation is given.  相似文献   

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The Triannulatus Complex of Anopheles (Nyssorhynchus) consists of at least three sibling species, namely Anopheles triannulatus s.s., Anopheles halophylus and a third undescribed member herein referred to as An. triannulatus "C". Sympatric anophelines belonging to species complexes, even though closely related, may exploit different environments such as larval habitats. In this paper we hypothesize that rainfall and seasonal flooding would distinctly influence the availability of larval habitats and consequently the seasonal population dynamics of sympatric members of the Triannulatus Complex. A reflection of this is distinct seasonal biting frequencies exhibited by three members of the Triannulatus Complex at a site in Central Brazil. Population dynamics seem to be influenced by the water level in the local rivers, although biting frequency of all three species was negatively influenced by rainfall. An. triannulatus s.s. was more abundant following the end of the rainy season, but notably 30 to 60 days after flooding. On the other hand, An. halophylus and An. triannulatus C peaked during the middle of the dry season, when water impoundments have no inflow, are somewhat reduced in size and the water becomes brackish. Differences in population dynamics were greater between An. triannulatus s.s. and An. halophylus and An. triannulatus C than between An. halophylus and An. triannulatus C. This might reflect differences in larval habitat exploitation and therefore spatial segregation among these members of the complex.  相似文献   

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Anopheles (Anopheles) sinensis [Wiedemann (1828)] is a member of the hyrcanus species group, and it has been incriminated as the natural or experimental malaria vectors in the Republic of Korea, Japan, China, and Indonesia. In Thailand, however, An. sinensis seems to be of little medical importance. Hybridization tests among the three iso-female lines (isolines) of An. sinensis [i.e., Form A (X, Y1) and Form B (X, Y2) (Thailand strain), and Form B (X, Y2) (Korean strain)] were established based on two distinct types of metaphase chromosomes and geographical differences The chromosomal form of the Korean strain was first identified from this study. Results of reciprocal and back crosses indicated that both karyotypic forms of theAn. sinensis Thailand and Korean strains were genetically compatible, and provided viable progenies and completely synaptic polytene chromosomes. The sequences of the rDNA internal-transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit II (COII) among the An. sinensis strains were nearly identical to each other, and the intraspecific sequence variability was very low (0.0-0.6%). Sequence comparisons among the cryptic inter-species (i.e., An. sinensis, An. lesteri, and An. yatsushiroensis), however, revealed extensive divergence, and the intraspecific variability ranged from 12.2 to 34.6%. Therefore, it is concluded from these results and previous vector ability studies that the An. sinensis Forms A and B exhibit cytological polymorphic races that have different vector abilities in their transmission of malaria, depending on their geographical locations.  相似文献   

19.
A study was conducted to determine the susceptibility of Anopheles sinensis larvae, malaria vector, from Paju‐shi (Gyonggi‐do) to 24 pesticides including 11 pyrethroids, 11 organophosphates, 1 pyrazole analogue and another pesticide. The mosquito larvae showed the most highly susceptible to chlorfenapyr with LC50 of 0.0063 ppm followed by spinosad, temephos, fenthion and beta‐cyfluthrin with 0.03, 0.0366, 0.0367 and 0.0998 ppm, respectively, and fluvalinate (>128 ppm) was the least susceptible. Also, 11 pesticides of them were compared with Goyang strain (Gyonggi‐do) of data 1992. The development of resistance was noticed to cypermethrin and permethrin as much of 73.59 and 6.23 folds at LC50, respectively, and also fluvalinate was showed high resistance development. In generally, the pyrethroid insecticides were showed higher development of resistance than organophosphorus insecticides.  相似文献   

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