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.     

Drift behaviour and microhabitat selection in the preimaginal stages of Simulium chutteri (Diptera Simuliidae)

The aquatic stages of the cattle biting pest, Simulium chutteri Lewis utilize river flow in their dispersal and colonization behaviour. Peaks of drifting activity in S. chutteri larvae occurred in the early morning and late afternoon. It is deduced that female flies scatter eggs onto slow flowing waters upstream of rapids. Larvae hatch from drifting eggs and colonize substrates in slower flowing regions upstream of rapids, while later stage instars move into faster flowing regions within rapids where they complete their development. This microhabitat selection by S. chutteri leads to rapid attainment of large population sizes in suitable sections of river and reduces competition between different stage larvae. In their utilization of a variety of microhabitats the larvae of this species differ from co-existing simuliid species which restrict developmental stages to single habitats.Catastrophic drift was recorded for S. chutteri larvae and could be a mechanism to regulate population size.Drift of simuliid larvae off rapids was not related to benthic population densities in the rapids and was therefore not due to excessive production. It is concluded that larval drift off rapids is related to habitat disturbances associated with water flow fluctuations and the activity of aquatic predators and other animals.The distribution of S. chutteri in the Vaal River is restricted by oviposition requirements of the adult female. Knowledge of drift behaviour and water flow requirements of Simuliidae have been applied to manage the population size of S. chutteri in the Vaal River.     

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。     

Cytosystematics of the Simulium tuberosum group (Diptera: Simuliidae) in Thailand

The polytene chromosomes of 3347 larvae of the Simulium tuberosum group in Asia were analysed, representing the largest ever cytogenetic study of black flies in the Oriental Region. Band‐by‐band comparisons, relative to the established standard chromosome map for the subgenus Simulium, revealed 17 cytogenetically distinct taxa in Thailand, plus an 18th in China. Six of these taxa correspond to morphologically described species (S. doipuiense, S. rufibasis, S. setsukoae, S. tani, S. yuphae and S. weji). Recognition of the 18 taxa is based largely on unique inversions, either fixed or sex linked, primarily in the long arm of chromosome III. The greatest cytological diversity was discovered in the S. tani lineage, with ten cytoforms. This marked chromosomal diversification within S. tani is based largely on two inversions that have assumed different roles over evolutionary time, variously functioning in different combinations as fixed inversions, sex‐linked inversions and autosomal polymorphisms. Shared unique chromosomal features, relative to the subgeneric standard chromosome map, allowed evolutionary relationships among the cytotaxa to be inferred. Fluctuations in climate during the Pleistocene might have promoted differentiation of the Southeast Asian S. tuberosum group in isolated refugia such as mountains. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 289–315.     

实蝇共生菌研究进展

实蝇类昆虫(双翅目Diptera:实蝇科Tephritidae)是重要的农业害虫,为害农作物茎秆和水果,严重影响农业生产和果蔬贸易,被许多国家列为重要的检疫性有害生物。实蝇共生菌对宿主实蝇的取食、生殖、发育及环境适应能力具有重要作用。目前,已有21个属的共生细菌(Enterobacter、Klebsiella、Citrobacter、Pseudomonas、Providencia、Erwinia、Acetobacter、Serratia、Proteus、Hafnia、Cedecea、Arthrobacter、Lactobacillus、Micrococcus、Streptococcus、Staphylococcus、Vibrio、Hafnia、Deinococcacea、Bacillus、Wolba-chia)以及1个属的共生真菌(Candida)被鉴定。其中,肺炎杆菌Klebsiella pneumoniae、产酸克雷伯氏菌Klebsiella oxytoca、成团泛菌Pantoea agglomerans、费氏柠檬酸杆菌Citrobter freundii、阴沟肠杆菌Enterobacter cloaca...     

Cytogenetics of Simulium siamense Takaoka and Suzuki, 1984 (Diptera: Simuliidae) in northeastern Thailand

We analysed salivary gland polytene chromosomes of 796 larvae from 17 populations of Simulium siamense in northeastern Thailand. Seventeen floating and two fixed chromosome inversions were recorded. Three cytoforms (A, F and G) were recognised and two of them are new (F and G). Cytoform F is distinguished by a fixed inversion on the long arm of chromosome II (IIL-8) and cytoform G by fixed inversions on the long arm of chromosome II (IIL-8) and short arm of chromosome III (IIIS-2). Significant departures from Hardy–Weinberg equilibrium due to heterozygote deficiency in geographically intermediate populations and absence of shared polymorphic inversions of the cytoforms indicate separation of the gene pool. Morphometric analysis of the larvae revealed significant differences in body length (F = 5.00, p =0.007) and head capsule width (F = 4.68, p = 0.010) among cytoforms.     

Phylogenetic analysis based on multiple gene sequences revealing cryptic biodiversity in Simulium multistriatum group (Diptera: Simuliidae) in Thailand

Phylogenetic relationships among four species of the Simulium multistriatum group (Diptera: Simuliidae) in Thailand were examined based on two mitochondrial genes (COI, COII) and one nuclear gene (18S/ITS1). Simulium takense was found to be genetically divergent (>20.3% for COI) from the other species, consistent with their distinctive morphology. Simulium chainarongi and S. chaliowae were monophyletic but were included in paraphyletic S. fenestratum. Simulium fenestratum was divided into three distinct lineages with high levels of genetic divergence. This suggests that S. fenestratum is a species complex. Neither morphological nor cytological examinations revealed evidence of sibling species. The clades derived from phylogenetic analyses were found to be correlated with the ecological conditions of larval habitat. Therefore, ecological adaptation may have played a role in black fly diversification and evolution. These results suggest the use of integrated, multidisciplinary approaches for fully understanding black fly biodiversity and systematics.     

贵州纺蚋亚属二新种(双翅目： 蚋科)

记述了采自贵州雷公山自然保护区的纺蚋二新种,清水纺蚋Simulium (Nevermannia) qingshuiense sp. Nov.和桥落纺蚋S. (N.) qiaolaoense sp. Nov.,二者均以其产地命名。文中对其成虫、蛹和幼虫形态进行了全面描述,并与其近缘种进行分类讨论。模式标本存放在贵阳医学院生物学教研室。     

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.     

青海特蚋亚属一新种(双翅目:蚋科)

Simulium (Tetisimulium) xiaodaoense sp. nov. is described based on the female specimens collected from Qinghai, China. This species is assigned to the subgenus Tetisimulium, and is closely related to S. (T.) tachengense An and Mahe, 1994 and S. (T.) wutaishanense An and Yan, 2003. However, it is clearly differentiated from them by the structure of gonapophyses, genital fork, genital plate, paraproct and cercus of the female. All the specimens are kept in the Medical Entomology Collection Gallery, Academy of Military Sciences, Beijing.     

河南省蚋属一新种(双翅目:蚋科)

记述采自河南1新种:河南纺蚋Simulium (Nevermannia) henanense, sp. nov.。根据其外生殖器的形状、幼虫和蛹的特征,本新种隶属于Simulium (Nevermannia)的宽足蚋组vernum-group。其蛹的特征与中国的 S. (N.) xinbinense 和西马来西亚的 S. (N.) kurtaki 相似,但是与后2种在雌虫股节的颜色、幼虫后颊裂和直肠腮的形状迥异,可资鉴别。模式标本存放于贵阳医学院生物学教研室。正模:♀,河南焦作云台山白龙潭,海拔 1 060 m,东经113°25',北纬35°14',韦静采;副模:1♀,12蛹,18幼虫,同正模。     

陕西省蚋属一新种记述(双翅目:蚋科)

Simulium (Simulium) liubaense, sp. nov. is described based on the female specimens collected from Liuba, Shaanxi Province, China. This species is assigned to the variegotum-group of the subgenus Simulium, and is closely related to S. (S.) jingfui Cai and An, 2008, S. (S.) taiwanicum Takaoka, 1979, S. (S.) hackeri Edwards 1928, S. (S.) chamlongi Takaoka and Suzuki, 1984. However it is clearly differentiated from them by the structure of cibarium, genital fork, genital plate, paraproct and cercus of the female. All the specimens are kept in the Medical Entomology Collection Gallery, Academy of Military Medical Sciences, Beijing.     

Phylogeography of the black fly Simulium tani (Diptera: Simuliidae) from Thailand as inferred from mtDNA sequences

Intraspecific phylogeography has been used widely as a tool to infer population history. However, little attention has been paid to Southeast Asia despite its importance in terms of biodiversity. Here we used the cytochrome oxidase I gene of mitochondrial DNA (mtDNA) for a phylogeographic study of 147 individuals of the black fly Simulium tani from Thailand. The mtDNA revealed high genetic differentiation between the major geographical regions of north, east and central/south Thailand. Mismatch distributions indicate population expansions during the mid-Pleistocene and the late Pleistocene suggesting that current population structure and diversity may be due in part to the species' response to Pleistocene climatic fluctuations. The genealogical structure of the haplotypes, high northern diversity and maximum-likelihood inference of historical migration rates, suggest that the eastern and central/southern populations originated from northern populations in the mid-Pleistocene. Subsequently, the eastern region had had a largely independent history but the central/southern population may be largely the result of recent (c. 100,000 years ago) expansion, either from the north again, or from a relictual population in the central region. Cytological investigation revealed that populations from the south and east have two overlapping fixed chromosomal inversions. Since these populations also share ecological characteristics it suggests that inversions are involved in ecological adaptation. In conclusion both contemporary and historical ecological conditions are playing an important role in determining population genetic structure and diversity.