兴义维蚋多线染色体研究（英文）

首次在国内对兴义维蚋Simulium (Wilhelmia) xingyiense的多线染色体进行研究, 并提供其多线染色体标准图。选取兴义维蚋的成熟幼虫, 用改良苯酚品红染色法进行唾腺多线染色体制备, 并进行测量、 描述及分析。结果表明： 兴义维蚋多线染色体数目为3对（2n=6）。Ⅰ号染色体具中央着丝粒, Ⅱ和Ⅲ号染色体均为亚中央着丝粒染色体。核仁组织者区位于Ⅰ号染色体短臂近着丝粒端。巴尔比尼氏环和双泡位于Ⅱ号染色体短臂近中央位置。3对染色体的着丝粒区可形成明显的染色中心。兴义维蚋多线染色体具有多态性的倒位, 倒位频率为0.64。兴义维蚋多线染色体的着丝粒、 核仁组织区、 巴氏环、 双泡等主要特征性结构的位置及形态恒定一致,可作为该种的重要鉴别特征。其多态性的倒位可为该蚋种在细胞水平上进行蚋类分类鉴别和系统发育等研究提供基础资料。     

Experimental hybridization between members of the Simulium damnosum complex

Abstract. Males of the Beffa form of Simulium soubrense Vajime and Dunbar were successfully crossed with female S.squamosum V. & D. and S.sanctipauli V. & D. Fertile eggs from both crosses were reared to larvae and, in the case of the BeifaXsquamosum cross, to adults.
Larval chromosomes from the Beffa x sanctipauli cross had normally paired homologues but those of the Beffa xsquamosum cross showed extensive asynapsis and large heterozygous loops. The morphology of the larval and adult hybrids from the BeftaXsquamosum cross were more characteristic of squamosum , but the adult males had scutal patterns typical of the Beffa form and retained this form's laboratory-mating propensity.     

Cytotaxonomy of four species in the Simulium perflavum species group (Diptera: Simuliidae) from Brazilian Amazonia

Polytene chromosomes of four members of the Simulium perflavum species group in Brazil are described, and a standard map for the species group is presented. Simulium rorotaense Floch & Abonnenc, S. perflavum Roubaud and an undescribed species (S.‘X’) are chromosomally conservative, each representing a single species with a unique preimaginal habitat. Chromosomal, morphological and ecological evidence indicates that S. maroniense Floch & Abonnenc, previously considered synonymous with S. rorotaense, is a good species. Independent morphological and chromosomal analyses yielded 99.4% agreement in separating larvae of S. rorotaense and S. maroniense. The two species can be distinguished by gill morphology or by a subterminal inversion on the long arm of chromosome III. Simulium maroniense consists of at least four cytotypes, each with different sex chromosomes and autosomal polymorphism profiles and associated with a particular landscape type, altitude, temperature regime or geographical location. Simulium rorotaense and S. maroniense share one unique inversion, as do S. perflavum and S. ‘X’, indicating two pairs of sister species. The anthropogenic S. perflavum probably dispersed into Central Amazonia sometime after the mid-1970s.     

A new species of Simulium (Nevermannia) (Diptera, Simuliidae) from Thailand, with keys to members of the Simulium feuerborni species-group in Thailand

Simulium (Nevermannia) maeaiensesp. n. is described on the basis of female, male, pupal and larval specimens collected from Chiang Mai Province, Thailand. This species is assigned to the feuerborni species-group of the subgenus Simulium (Nevermannia), and is distinctive among this species-group in having the female cibarium furnished with numerous dark minute conical processes on the lower part, the female genital fork with a strongly sclerotized horizontal bar on each arm, and six long pupal gill filaments arising nearly at the same level from the common basal stalk and lying in a horizontal plane. Identification keys to seven species of the feuerborni species-group reported from Thailand are provided for females, males, pupae and mature larvae.     

Cytotaxonomy, morphology and ecology of the Simulium nobile species group (Diptera: Simuliidae) in Thailand

The polytene chromosomes of 512 larvae of the Simulium nobile species group collected from 16 stream sites in northern, central and southern Thailand were examined. Band-by- band comparisons relative to the established standard chromosome map for the subgenus Simulium distinguished the 2 species of this group, S. nobile and S. nodosum. The differences are mainly due to the position of the nucleolar organizer, pseudochromocenter, and fixed and polymorphic inversions. S. nobile is a monomorphic species, while S. nodosum is a polymorphic species. The morphology of these taxa is described based on the gill filaments and the color of the antennae and female genitalia. S. nobile is distributed in southern Thailand at low altitudes, whereas the distribution of S. nodosum is in the north at higher altitudes.     

Features of larval development in Simulium buissoni Roubaud, 1906, and S. sechani Craig and Fossati, 1995 (Diptera: Simuliidae) in the Marquesas Archipelago (French Polynesia)

Two anthropophilic species are known from the Marquesas archipelago (French Polynesia): Simulium buissoni Roubaud, 1906 and S. sechani Craig & Fossati, 1995. The need to control them requires good knowledge about their larval growth, larvae being the only stage actually susceptible to control. A biometric study based on cephalic measures of the two species, shows that they both have seven larval instars. Size variations following species and sampling sites are examined, as are variations of the sex of the two last larval instars. A recolonization experiment, after treatment of a part of a river, allows us to quantify larval growing length of S. buissoni, which is about 12 days. These data allow us to determine the optimal treatment frequency.     

Life-history and distribution of Simulium austeni (Diptera: Simuliidae) in relation to phytoplankton in some southern English rivers

SUMMARY. Regular sampling of larval and pupal simuliids in the River Stour (Dorset) showed that Simulium austeni produces a single generation of larvae per year, pupating in late April-early May. The species is abundant in the middle and lower reaches of the Stour and its larger tributaries, but in nearby rivers of comparable size it is rare or absent, Unlike these other rivers, the Stour supports a true phytoplankton dominated by small centric diatoms ( Stephanodiscus hantzschii ). Peak concentrations of particulate chlorophyll-α sometimes correspond with the growth period of S. austeni larvae. The distribution of S. austeni relative to that of phytoplankton is discussed and the importances of suspended bacteria and water chemistry are briefly considered.     

Cytogenetics and evolution of Simulium ornatipes skuse (Diptera:Simuliidae) I. Sibling speciation

Larval populations of the morphologically distinct species Simulium ornatipes and S. neornatipes and a subspecies of the former, S. ornatipes norfolkense, were analysed using polytene chromosome cytology. Fixed inversion differences, distinct differentiated sex chromosomes and unique arrays of chromosomal polymorphisms reveal two sibling species, S. ornatipes A and B, within S. ornatipes, and two, S. neornatipes 1 and 2, within S. neornatipes. Chromosomally S. ornatipes norfolkense is similar to S. ornatipes A. An unprecedented level of shared inversion polymorphism is shown by S. ornatipes A and B indicating a very close relationship between them. While it may be postulated that such a situation has arisen by independent origin of the shared inversions within each species, or by introgression of these rearrangements between the two species, it is concluded that the shared polymorphisms in fact originate from a common ancestor. Within the four chromosomally defined species, differentiated sex chromosome systems occur which may involve any of the three chromosome pairs. Simulium ornatipes A is particularly interesting because there are indications that it may be polymorphic for differentiated sex chromosomes on two different elements and that it may also share a sex chromosome marker with S. ornatipes B, a unique situation in the Simuliidae. The evolution of sex chromosome systems in the four species is compared with that of other Simulids and its intimate connection with speciation emphasised. Finally the data on fixed inversions, differentiated sex chromosomes and shared polymorphisms is used to construct a phylogeny of the four species outlining their patterns of speciation.     

Cladistic analysis of Simulium (Trichodagmia) and Simulium (Thyrsopelma) (Diptera: Simuliidae)

A cladistic analysis of Simulium ( Trichodagmia ) sensu Crosskey and Howard, using 34 morphological characters of larvae (6 characters), pupa (5) and adults (23), yields nine most parsimonious trees under equal weights (length 101 steps CI 0.49 RI 0.73). Successive weighting based on the maximal rescaled consistency index preferred one of the nine (31.37 steps CI 0.62 RI 0.87 total fit_con3= 235.8), which was also one of two trees found under implicit weights with concavity values of 3–6. The cladogram justifies the recognition of two subgenera. Simulium ( Trichodagmia ) sensu stricto (containing S. muiscorum, sumapazense, S. wygodzinskyorum, S. nigrimanum, S. chalcocoma, S. huairayacu and S. lahillei ) is supported by the branchial tip sclerotization and the presence of cibarial teeth, larval body tegument covered with lanceolate hairs, female with simple claw, and gonapophysis size. Simulium ( Thyrsopelma ) (containing S. scutistriatum, S. hirtipupa, S. orbitale, S. guianense, S. perplexum and S. itaunense ) is supported by the hypostomial teeth.     

Black flies (Diptera: Simuliidae) of French Guiana: cytotaxonomy and a preliminary list of species

The objectives of the present study were to broaden the survey of simuliid species in French Guiana and to cytologically analyze the species in the Simulium perflavum species group. Twelve species of Simulium were collected from which S. goeldii, S. quadrifidum, S. trombetense, S. near incrustatum, S. metallicum (s.l.) sp1, S. metallicum (s.l.) sp2 and S. ochraceum (s.l.) are reported for the first time for this region. The only species collected in the S. perflavum group was S. rorotaense; 34 larvae of this species were cytologically analyzed, all of which had the standard sequence. S. metallicum (s.l.), S. ochraceum (s.l.), S. guianense (s.l.) and S. oyapockense (s.l.) are involved with transmission of onchocerciasis in Central and South America, however, in French Guiana these species were not found biting humans during the sampling period. With the few collections made during this study, we increase the number of simulid species known in French Guiana from 6 to 13. It is clear that more simuliid species can be expected to be found when more sampling is done, including collections in other ecoregions in French Guiana.     

Four new cytotypes of the onchocerciasis vector blackfly Simulium guianense in Brazil

Abstract. Simulium (Trichodagmia) guianense is an important Amazonian vector of onchocerciasis. Examination of the polytene chromosome banding patterns of larvae from five sites in Brazil revealed the occurrence of four cytotypes, designated A, B, C and D. The chromosomal standard, Simulium guianense A , occurred at two localities in Goias State (on the Rio Tocantins and Rio Mucambao) where it was the only cytotype. The other three sites examined yielded one different cytotype from each: B from Rio Oyapoque in Amapa State, C from Rio Tocantins in Maranhao State, and D from Rio Xingu in Para State. All cytotypes differed by at least two fixed inversions, but a sex determining system was not evident in any cytotype. As the cytotypes have been found allopatrically it is not certain that they represent sibling species; sampling of sympatric populations would resolve this. During certain times of the year, voracious anthropophagy by S.guianense sensu lato occurs at the localities sampled for cytotypes A, C and D (biting data are not available for the cytotype B locality). In some other areas, however, S.guianense s.l. is entirely zoophilic. Further studies are needed, therefore, to elucidate the biting habits, vectorial capacity, geographic distribution and taxonomic status of these four, and perhaps additional, cytotypes comprising the S.guianense complex.     

Assessment of rDNA IGS as a molecular marker in the Simulium damnosum complex

For five cytospecies of the Simulium damnosum Theobald complex of blackflies (Diptera: Simuliidae) from West Africa, both ends of the intergenic spacer region (IGS) of the rDNA have been sequenced with the aim of developing specific molecular markers. No specific differences in these two regions were detected between Simulium sanctipauli V. & D., Simulium sirbanum V. & D., Simulium soubrense V. & D., Simulium squamosum Enderlein and Simulium yahense V. & D., except in the number of A subrepeats at the 5' end of the IGS (two in S. squamosum and four or five in the others) and in position 310 of the 3' end (a C in S. squamosum and a G in the others). However, genetic distances within and between species overlapped. These DNA sequences had no strong phylogenetic signal, and the trees obtained were mostly unresolved. Although most sequences from S. squamosum clustered together, a few of them were more similar to those in other cytospecies. These results could be explained either by hybridization with genetic introgression or by ancestral polymorphism and recent speciation.     

贵州蚋属一新种(双翅目：蚋科)

记述采自贵州雷公山的蚋属一新种, 显著蚋Simulium (Simulium) prominentum, 新种。根据其蛹和幼虫的特征显著而命名, 对其幼期形态进行描述并与其近缘种作分类讨论。     

贵州蚋属一新种 (双翅目：蚋科)

 记述采自贵州雷公山的蚋属一新种, 显著蚋Simulium (Simulium) prominentum, 新种 。根据其蛹和幼虫的特征显著而命名, 对其幼期形态进行描述并与其近缘种作分类讨论。     

Two new species of Simulium (Gomphostilbia) (Diptera, Simuliidae) from Peninsular Malaysia, with keys to Peninsular Malaysian members of the Simulium ceylonicum species-group

Two new species of black flies, Simulium (Gomphostilbia) roslihashimisp. n. and Simulium (Gomphostilbia) lurauensesp. n., are described on the basis of reared adult, pupal and larval specimens collected from Peninsular Malaysia. These two new species are placed in the ceylonicum species-group within the subgenus Gomphostilbia. Simulium (Gomphostilbia) roslihashimisp. n. is most distinctive with the male having almost entirely yellow antennae, and Simulium (Gomphostilbia) lurauensesp. n. is characterized in the female by having the elongate sensory vesicle and the yellowish-white hairs on the base of the costal vein and on the stem vein, in the male by the greater number of large upper-eye facets and the spindle-shaped hind basitarsi which are much narrower than the hind tibiae and femora and in the pupa by the small terminal hooks. Keys to species of the ceylonicum species-group reported from Peninsular Malaysia are provided for females, males, pupae and mature larvae.     

C banding in polytene chromosomes of Simulium ornatipes and S. melatum (Diptera: Simuliidae)

Polytene and mitotic chromosomes of Simulium ornatipes and S. melatum were subjected to C banding procedures. In both species polytene chromosomes consistently show C banding of centromere regions, telomeres, nucleolar organiser and, unexpectedly, numerous interstitial sites. The interstitial C banding sites correspond to morphologically single polytene bands. Their response is graded and independent of band size. Interstitial C bands in S. ornatipes are scattered throughout the complement, whereas in S. melatum they are clustered. Supernumerary heterochromatic segments in S. ornatipes also exhibit strong C banding and inverted segments can differ from standard in C banding pattern. — Mitotic chromosomes of both species show a single centric C band with indications of two weak interstitial bands in S. ornatipes, suggesting that many C band regions, detectable in polytene chromosomes, are not resolved by present techniques in mitotic chromosomes. — Contrary to current opinion that C banding is diagnostic for constitutive heterochromatin, the interstitial C band sites of polytene chromosomes are regarded as euchromatic. Conversely, the heterochromatic pericentric regions of S. ornatipes are not C banded. — It appears that polytene chromosomes offer a promising system for the elucidation of C banding mechanisms.     

The Simulium vernum group (Diptera: Simuliidae) in Europe: multiple character sets for assessing species status

The value of using characters from multiple sources – chromosomes, ecology, gene sequences, and morphology – to evaluate the species status of closely related black flies is demonstrated for three European members of the Simulium vernum group: Simulium crenobium (Knoz, 1961), Simulium juxtacrenobium Bass & Brockhouse, 1990, and Simulium vernum s.s. Macquart, 1826. Simulium juxtacrenobium is a chromosomally, molecularly, and morphologically distinct species that diverged from S. crenobium and S. vernum s.s. about 2 Mya. It is specialized for intermittent streams, is univoltine, and is recorded for the first time from northern Europe, based on collections from Finland and Sweden, representing a range extension of about 1800 km. In contrast, S. crenobium, although confirmed as a distinct species, differs from S. vernum s.s. by only a few larval and chromosomal characters, and by a breeding habitat restricted to mountain spring brooks. Whereas all four character sets independently support the specific distinctness of S. juxtacrenobium and S. vernum s.s., multiple character sets are required to establish the specific validity of S. crenobium.     

Seasonal and diurnal biting activities and zoonotic filarial infections of two Simulium species (Diptera: Simuliidae) in northern Thailand

Seasonal and daily biting activity patterns, and natural filarial infections of adult black flies attracted to human bait were investigated at Ban Pang Faen, a rural area in Chiang Mai Province in northern Thailand. Collections were carried out twice a month from 0600 to 18-00 hours from January 2005 to February 2006. Among ten Simulium species collected, S. nodosum and S. asakoae were predominant occupying 57.3% and 37.2% of the total 16,553 females, respectively. These two predominant species showed different patterns in seasonal abundance: majority of S. nodosum (86.7%) were collected in hot season (from mid February to mid May), while most of S. asakoae (74.5%) were collected in rainy season (from mid May to mid October). For the daily biting activity, S. nodosum had two patterns: the main one was unimodal with a peak from 17-00 to 18-00, and the other was bimodal and had the major peak from 1600 to 18-00 and the minor one from 07-00 to 09-00. The pattern of S. asakoae was mostly unimodal with a peak from 06-00 to 10-00. The filarial larvae found in S. nodosum and S. asakoae were morphologically different from each other. The short and thick infective larvae found in S. asakoae differed from all known filarial larvae; it is suggested that they might be a bird parasite, Splendidofilariinae or Lemdaninae. The infection of the mammophilic S. nodosum with large Onchocerca type infective larvae was confirmed in this area. Natural filarial infections were found in each month (except December) in either S. nodosum or S. asakoae or in both. Monthly infection rates with all stages of larvae were 0.6-5.0% for S. nodosum, and 1.0-4.0% for S. asakoae. It is suggested that people in this village are exposed to the risk of infection with zoonotic filariae throughout the year.     

DNA in situ hybridization on polytene chromosomes of Simulium sanctipauli at loci relevant to insecticide resistance

A DNA technique for in situ hybridization developed by Kumar & Collins (1994) for use on polytene chromosomes of adult Anopheles mosquitoes (Diptera: Culicidae) was modified for use with Simulium larval salivary gland chromosomes (Diptera: Simuliidae). Cloned fragments of several Simulium genes (coding for aspartate amino transferase, cytochrome P450 and DNA polymerase) were successfully mapped physically by assigning specific band locations in Simulim sanctipauli V. & D. This represents the first attempt at locating genes beyond the resolution of linkage to inversions in any blackfly species.     

Genetic variation tracks ecological segregation in Pacific island black flies

Geographic isolation is widely viewed as a key component of insular radiations on islands. However, strong ecological affinities may also reinforce isolation and promote genetic divergence. The black fly fauna in the Society Islands French Polynesia is notable for the number of closely related endemic species (31), and the morphological and habitat diversity of the larvae. Here, we measure ecological and morphological differences within and between two closely related species, Simulium oviceps and Simulium dussertorum and relate these differences to genetic distance. Phylogenetic analyses of a 920 bp fragment of the cytochrome oxidase I (COI) gene revealed a well-supported, ecologically divergent S. oviceps clade (larvae found in rivers instead of cascades) that shows little morphological differentiation. For both S. oviceps and S. dussertorum, genetic distance among populations is related to larval habitat, with cascade populations showing greater isolation from each other than river populations. Our data support the hypothesis that larval ecological shifts have played a role in the radiation of this black fly fauna.