Chironomidae (Diptera) in paleoecology

A comprehensive review of chironomid paleoecology is provided, with a discussion of relevant aspects of chironomid biology. The systematics, ecology, morphology, and taphonomy of chironomids are specifically addressed, as is the application of chironomid remains in investigations of lake ontogeny, anthropogenic eutrophication and acidification, paleosalinity, and paleoclimate.     

荒漠绿洲边缘凝结水量及其影响因子

以2004年7~10月在临泽内陆河流域综合研究站凝结水试验观测数据为基础,讨论了荒漠绿洲边缘凝结水凝结过程、不同下垫面凝结量及其影响因子.结果表明:荒漠绿洲边缘凝结水以吸湿凝结为主,北京时间16:00~18:00开始,至次日7:00~8:00结束.凝结开始的时间受控于沙地含水量,凝结量则主要受近地表相对湿度、近地表气温以及气温日较差三方面因素的影响.人工草地、平坦无植被沙地、沙丘顶部、丘间低地和人工林地在7~10月的平均月凝结量分别为:5.1 mm、4.0 mm、3.1mm、1.8 mm和1.0 mm.     

Research Progress on Assessing the Impacts of Urban Expansion on Natural Habitats

Urban expansion has become one of the main factors influencing natural habitats. Understanding the advances on the assessments of the impacts of urban expansion on natural habitats is of great significance to balance the contradiction between urban expansion and natural habitats protection and to improve urban sustainability. Therefore, this paper reviewed the assessments of the impacts of urban expansion on natural habitats. The results showed that the number of papers and the frequency of citations continuously increased. Previous studies mainly evaluated the impacts of urban expansion on natural habitats in broad sense, and emphasized the impacts on the area and spatial patterns of natural habitats. The scale of previous studies concentrated on the local scale, and the spatial statistics were used as the most popular assessment method. Previous studies have laid a good foundation for understanding the impacts of urban expansion on natural habitats, but there are shortcomings in several aspects of contents, scales and methods. To solve those shortcomings, we propose a framework for assessing the impacts of urban expansion on natural habitats based on the principle of "multiple perspectives, multiple scales, and multiple methods". This framework will be helpful to assess the impacts of urbanization on natural habitats in a more effective way.     

Current Status of Scientific Deep-diving Investigations in Submarine Canyons

Submarine canyons represent one of the most important geomorphologic features in continental margins, act as one of the most important conduits of seafloor sediment transporting from shallow waters into the deep sea, and are also biodiversity hotspots. Submarine-canyon investigations are therefore significant for seafloor scientific research, submarine mineral and resource exploitation, and the construction and safety operation of submarine infrastructures. Deep-sea diving by manned submersibles and robot submersibles represented by Remotely Operated Vehicles (ROV) and Autonomous Underwater Vehicles (AUV) provides an important approach to the investigation of modern submarine canyons. The biggest advantage of manned submersibles is that they can bring scientists to the deep sea for in-place observations and precise sampling, while the robot deep-sea diving has the advantages of low cost, high efficiency, no personnel safety concerns, and the ability to reach the extreme sea areas that are difficult for humans to reach. Deep-sea diving has found broad applications in the geo-scientific research of submarine canyons. These studies cover seafloor topography and geomorphology, seafloor sediments, erosional and depositional bedforms, mass transport processes and flow dynamics, cold springs, cold-water corals and other biological habitats, as well as seafloor biological erosion. The research experience and scientific findings in scientific diving investigation of submarine canyons accumulated by the developed countries in Europe and the United States over the past 70 years are of great reference and significance to the emerging scientific deep-sea diving in China.     

Late glacial impacts on dispersal and colonization of Atlantic Canada and Maine by freshwater fishes

Late glacial scenarios of ice retreat and biogeography databases constrain the dispersal routes of obligate freshwater fishes into Atlantic Canada and Maine. Evidence indicates glacial ice covered the present-day mainland and offshore islands at 18,000 ¹⁴C yr before present. Possible refugia for extirpated freshwater fishes were the exposed outer edge of the Grand Banks (east), exposed Georges Bank (south-Atlantic Refugium), and the Mississippi Refugium in the west. It is improbable that the region was recolonized from the offshore refugia. Rather, fishes recolonized from the east via the upper St. Lawrence River valley into the upper Saint John River, Maine (Lake Madawaska) from 11,000 to 12,000 ¹⁴C yr BP. The short period of entry resulted in the low diversity of obligate freshwater species in the region. Lake Madawaska was breached and dispersal continued into the remainder of the region after 8000 ¹⁴C yr BP. By 6000 ¹⁴C yr BP, access routes to the east along low-lying coastal zones were blocked by rising sea levels, which isolated Prince Edward Island, Cape Breton Island, and most probably Nova Scotia. Natural dispersal across the region appeared complete by this time.     

Two new long-legged flies in the Santonian amber of France (Diptera: Dolichopodidae)

Avenaphora gallica sp. nov., second representative of this dolichopodid genus, and Cretomicrophorus piolencensis sp. nov., third representative of this genus, are described from a new lower Santonian amber outcrop in Southern France. The relationships of Avenaphora in the Empidoidea are discussed. Avenaphora gallica and Cretomicrophorus piolencensis were found in a marine littoral swamp palaeoenvironment, as for many modern Parathalassiinae.     

The first fossil hilarimorphid fly (Diptera: Brachycera)

Although recent molecular phylogenetic analyses suggest a great antiquity, going into the Jurassic, for the small modern fly family Hilarimorphidae, no fossil was attributed to this group. The first fossil hilarimorphid Cretahilarimorpha lebanensis gen. et sp. nov., is described, based on a specimen from the Lower Cretaceous Lebanese amber. Its external morphology is analysed and compared with that of Hilarimorpha, unique modern hilarimorphid genus. The differences concern the wing venation, antenna and especially mouthparts. Cretahilarimorpha has very elongate mouthparts, adapted for nectar feeding or (less probably) for predation on other insects. Several other Lower Cretaceous lineages have developed similar elongate mouthparts, viz. nemestrinid and xylomyiid flies, and the Mecoptera: Aneuretopsychina, probably adapted to still unknown deep nectar-producing flowers. A checklist of species belonging to the Hilamorphidae is given.     

Phylogenetic Problems in Polynesian Simuliidae (Diptera: Culicomorpha): A progress report

As a basis for eventual control of the vicious anthropophilic and ornithophilic simuliid females of the Marquesas Islands, a taxonomic revision of Polynesian Simuliidae is in progress. Cytotaxonomic studies reveal two simuliid species in Rarotonga, Cook Islands; nine species in Tahiti, Society Islands, and two in the Marquesas Islands. A cytophylogeny is now available. Polynesian Simuliidae are unique in possessing heterogametic females. A reconstructed phylogeny, based mainly on morphological character states of larvae and pupae, agrees well with the cytophylogeny. One of the new species which is closely related to Simulium oviceps Edwards has larvae with highly reduced, non-functional cephalic fans. Ages of the Polynesian islands are discussed in relation to possible dispersal of Simuliidae into Polynesia.     

Recent Progress and Perspectives in Paleoenvironmental and Paleoclimatic Research Based on Chironomidae (Diptera)

Chironomidae (Diptera) becomes a rapid developing proxy in the international paleolimnology in the recent 20 years due to its short life cycle, strong ability to move and sensitive response to environmental change. The main progress of paleolimnological research based on chironomid can be summarized as the following four aspects: ①The establishment of a large number of sample training sets and transfer functions, as well as the comparison and integration of regional databases; ②More attention on the role of internal lacustrine factors in controlling of the chironomid population; ③Attention on finer time scales since the modern interglacial period; ④Improvement of the experimental technology and numerical methods, and constant development of new indicators. The domestic related research started late, but databases in the middle and lower reaches of the Yangtze river, the Tibetan Plateau, the Yunnan Plateau and the region of inner Mongolia and Xinjiang has been established so far, and also some researches on the internal lacustrine factors on chironomid population has been carried out; paleoenvironmental reconstruction is mainly concentrated in the northwest arid areas and the Yunnan Plateau, and the research in eastern region is primarily focused on reflecting the effects of recent state of human activities on the lakes. Paleoenvironment and paleoclimate researches based on chironomid urgently need to ①Carry out more individual ecology work to accurately understand the relationship between the species and environmental factors, combined with the investigation of a broader area; ②Further improve the efficiency of experiments by new technology to enhance the resolution of identification; ③Pay attention to the application of the advanced quantitative ecology methods and the novel tools such as isotopic analysis; ④Attach great importance to the role of chironomid in the definition of lake natural state and the ecological restoration.     

New species of Limoniidae (Diptera) from Myanmar amber,Upper Cretaceous

A new species of Dicranoptycha Osten Sacken, 1860, Dicranoptycha plicativa sp. nov., and a unassigned species are illustrated and described from Myanmar (Burmese) amber (lowermost Cenomanian, Upper Cretaceous). A complete list of fossil species of the genus Dicranoptycha is summarized. In addition, an updated key to the known fossil species of the Dicranoptycha is provided.     

First fossil insect from Lower Cretaceous Lebanese amber in Syria (Diptera: Ceratopogonidae)

Lebanoculicoides bloudani a new species of Ceratopogonidae from the Lower Cretaceous ambers of Syria and Lebanon is studied. The new species is characterized, described, illustrated, and compared with the other fossil taxa of the same extinct genus. A key to the species of the genus Lebanoculioides is proposed.     

A new genus and species of snipe fly (Diptera: Rhagionidae) in Lebanese Cretaceous amber

The rhagionid Lebanoleptis huangi gen. et sp. nov. is described from the Lower Cretaceous amber of Lebanon. It is characterized, illustrated, and compared with the recent and fossil genera having the same particular absence of wing vein M3. Other Mesozoic flies with similar venation and currently attributed to the Rhagionidae are briefly discussed and should be revised.     

New Fossils of Eoptychopteridae (Diptera) from the Middle Jurassic of Northeastern China

Three new species of the extinct genus of Eoptychopterina from the Eoptychopteridae     

New Fossils of Eoptychopteridae (Diptera)from the Middle Jurassic of Northeastern China

Three new species of the extinct genus of Eoptychopterina from the Eoptychopteridae family, Eoptychopterina antica sp. nov., Eoptychopterina adnexa sp. nov., and Eoptychopterina mediata sp. nov., are described and illustrated. These three new species are established based on fossil specimens with bodies and complete wings. All were collected from the Middle Jurassic Jiulongshan Formation of Daohugou in eastern Inner Mongolia, China. Based on the new materials, the name of two species in Eoptychopterina from China--Eoptychopterina elenae Ren and Krzeminski and Eoptychopterina gigantea Zhang--is sysnonymum junius.     

First recorded evidence in the fossil record of snipe flies (Diptera: Rhagionidae) in Cretaceous amber, France

Novelaria, a new genus of rhagionid of late Albian age with three new species, is the first record of this family from Charentes amber (southwestern France). The new genus is probably closely related to the recent genus Chrysopilus. However its relationship with the other fossils in amber is discussed. A key for separation of the new species is provided and the diversity of the family during the Cretaceous is also briefly discussed.     

Food habits of two larval flies (Dolichopodidae: Diptera) in two gulf coast oligohaline tidal marshes

Food habits of two species of dolichopodid fly larvae, from two Gulf Coast oligohaline tidal marshes, were analyzed from monthly collections taken between June 1979 and May 1980. Larvae ofPelastoneurus abbreviatus Loew andThinophilus frontalis Van Duzee, taken from aJuncus roemerianus Scheele dominated marsh, fed predominantly on oligochaetes and nematodes.Pelastoneurus abbreviatus, collected in a nearbySpartina cynosuroides (L.) Roth marsh, also fed on oligochaetes but consumed more polychaetes than nematodes. By being predators and prey in turn, these larvae serve in the transfer of energy between benthic, aquatic, and terrestrial components of the marsh, system.     

New Eoptychoptera (Insecta: Diptera,Ptychopteridae) from the Lower Cretaceous of Spain

A new species, Eoptychoptera cantabrica sp. nov. is described from the Albian El Soplao amber-bearing deposits based on a single male with an elongated proboscis, unknown among extant members of Ptychopteridae. It represents the youngest record of the species-diverse genus Eoptychoptera. A pupa of Eoptychoptera sp. with a long respiratory horn, typical of extant ptychopterids, is described from Las Hoyas limestones, where adult fossil ptychopterids have yet to be discovered. A key to species of Eoptychoptera, based on wing venation, and a distribution map of Cretaceous Ptychopteridae are provided. The climatic preferences and mouthparts of Mesozoic and recent Ptychopteridae are discussed.     

A new tribe of Diamesinae (Diptera: Chironomidae) from the Lower Cretaceous of Mongolia

A new tribe of Diamesinae, Eugenodiamesini tr. nov. (Diptera: Chironomidae), is described based on a single pupa from Khutel Khara (lower part of the Tsagan Tsab Formation, Lower Cretaceous of Mongolia). The most distinctive characters of the new taxon are numerous multibranched lateral setae on tubercles along entire margins of abdominal segments II–VIII, and a unique setation of the anal lobes, with two multibranched anal macrosetae on each side and one simple near the apex. The fossil is the oldest known member of Diamesinae.     

A remarkable brachyceran fly (Diptera: Tabanomorpha) from Late Cretaceous Burmese amber

A new brachyceran fly (Diptera: Tabanomorpha), Pseudorhagio zhangi gen. et sp. nov., is described from Late Cretaceous Burmese amber. It is tentatively placed as Family incertae sedis in Tabanomorpha and distinguished from other Tabanomorpha by the following unusual combination of characters: head wider than thorax; body densely covered with fine and short setae, devoid of macrosetae; scutum strongly convex, nearly spherical; scutellum rather small, convex; antennal flagellum elongated, tapering, unsegmented; vein R4 perpendicular to R5, and strongly curved; crossvein m-m very long, strongly sinuated; tibial spur formula 0, 2, 0. This discovery further confirms the high diversity of Tabanomorpha in Late Cretaceous Burmese amber. An updated list of brachyceran species in Burmese amber is given.     

The first trichomyiine from Burmese Cretaceous amber (Diptera,Psychodidae, Trichomyiinae)

A new genus and species of Trichomyiinae (Axenotrichomyia boisteli) is described herein from Burmese Upper Cretaceous (Cenomanian) amber. This new taxon is characterized, illustrated, and its taxonomic position is discussed. This discovery sheds new light for the understanding of the palaeobiodiversity of this group.