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1.
The distribution of adult Trichoptera in light traps was investigated alongside nine streams draining catchments under native forest, pine forest, or pasture near Hamilton, Waikato, New Zealand. The aim of the study was to determine the relationship between abundance, taxonomic richness, and community composition with respect to land use during summer, and to evaluate the use of adult Trichoptera compared with benthic invertebrates as potential bio‐indicators of the effectiveness of land‐management changes. Adult Trichoptera faunas alongside the native streams were dominated by Hydrobiosidae, Conoesucidae, and Helicopsychidae (each >10% of total Trichoptera numbers for at least two of the three sites), whereas Leptoceridae, Oeconescidae, and Hydrobiosidae were relatively abundant alongside at least two of the pine sites. Adult Trichoptera faunas at the pasture sites were strongly dominated by Hydroptilidae which made up 47–85% of numbers caught at all sites. The mean number of individuals and taxa caught in light traps increased from November to January and then declined in February for all land‐use types. Overall, total numbers and taxonomic richness of adult Trichoptera were significantly lower at the pine sites compared to the pasture or native sites. TWINSPAN classification of benthic invertebrates collected in November clearly differentiated sites based on land use for presence/absence and percentage abundance data. A similar pattern was evident for most sites when adult Trichoptera faunas were used for the four sampling dates combined, suggesting that light trapping has potential as a tool for bio‐monitoring. 相似文献
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Diverse caddis flies are recently collected from the Middle Jurassic Daohugou fauna in Ningcheng County, Inner Mongolia, northern China, and different types of caddis cases have been reported in the same locality. A new species of caddisfly, Liadotaulius daohugouensis sp. nov. is described and illustrated; the establishment is based on a well-preserved isolated forewing collected from the Middle Jurassic Jiulongshan Formation of Daohugou. The family status of Liadotaulius is discussed on the basis of new material and is referred to the family Philopotamidae. The Daohugou fauna continues to provide new data for studying the early evolution of Trichoptera. 相似文献
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The following new fossil trichopteran insects are described or revised from the Purbeck Limestone Group and Wealden Supergroup of southern England: Pteromixanum inviolatum gen. et sp. nov., P. ruderatum gen. et sp. nov., P. purbeckianum (Handlirsch) gen. et comb. nov. and P. poxwellense gen. et sp. nov. (Necrotauliidae);Purbimodus minor gen. et sp. nov., P. medius gen. et sp. nov., P. rasnitsyni gen. et sp. nov. and P. saxosus gen. et sp. nov. (Vitimotauliidae);Palaeoludus popovi gen. et sp. nov. (Dysoneuridae);Palaeotarsus desertus gen. et sp. nov. (Plectrotarsidae);Eucrunoecia ridicula gen. et sp. nov. (Lepidostomatidae);Palaeocentropus placidus gen. et sp. nov. (Calamoceratidae) and Helicophidae gen. et sp. incertae sedis. The general composition of the fauna is compared with Early Cretaceous faunas of Asia. The early appearance of several living families is noted. 相似文献
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Trichoptera have been utilised infrequently in palaeoecological studies despite their value as environmental indicators of freshwater habitat structure and quality, via their aquatic larvae, and catchment macroclimate conditions, via the aerial adults. Two sites, dated ca. 11 600 14C yr BP, in the middle reaches of the River Trent (England) supported caddisfly (Trichoptera) assemblages indicative of a dynamic braided river with extensive floodplain development. At the first, Barrow‐upon‐Trent, the caddisfly assemblage was dominated by taxa indicative of a medium to large gravel‐bed river (Lepidostoma hirtum, Micrasema setiferum and taxa from the family Hydropsychidae). At the second site, Hemington, the caddisfly fauna was dominated by taxa from the families Limnephilidae and Phryganeidae. These usually occur in slow flowing and standing waters and are indicative of cut‐off channels on the floodplain. Micrasema setiferum does not occur in the contemporary UK fauna and has a modern distribution across central Europe and Fennoscandia. A gridded climatology extracted for those geographical areas where M. setiferum occurs today indicated a greater degree of continentality than currently prevailing in the Trent catchment. The value of Trichoptera in palaeoecological studies is explored and a model of channel evolution for the River Trent is presented based on caddisfly data. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Caddisfly (Trichoptera) larvae are an abundant and widespread aquatic insect group characterized by the construction of silk structures, including nets and cases. Case-building caddisfly have the potential to modify the sorting and mobility of sand and fine gravel via: (1) case construction, resulting in altered sediment properties; (2) transporting sediment incorporated into cases over the river bed; and (3) changing the structure of river beds via burrowing activity. To investigate these mechanisms, it is necessary to understand the mass, size distribution and spatial variability of sediment use by case-building caddisfly larvae. We quantified the mineral sediment used by individuals and communities of case-building caddisfly in 27 samples, from three sites on a gravel-bed stream. The mass and size distribution of sediment in individual cases varied between taxa (mass = 0.001–0.83 g, D50 = 0.17–4 mm). The mean mass of sediment used by the caddisfly community was 38 g m−2 and varied locally. Sediment use was predominantly coarse sand (D50 = 1 mm). 64% of sediment use was attributable to Agapetus fuscipes (Glossosomatidae). Due to within-species variability in case mass, the abundance of most taxa, including A. fuscipes, was only weakly associated with the mass of sediment used by this species, at the river scale. Whilst the caddisfly community used a small percentage of the total sediment available (average 2.99% of the 1–1.4 mm size fraction), A. fuscipes used more fine sediment in their cases at sites where it was more available. Despite variability in local habitat, all sites supported diverse case-building caddisfly communities utilizing mineral sediment. Consequently, geomorphological effects of case-building caddisfly are potentially widespread. The results provide novel insights into the specific grain sizes and quantities of fine sediment used by caddisfly larvae, which represents an important step towards understanding their zoogeomorphic activities. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd. 相似文献
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Mark Harthun 《Limnologica》1999,29(4):449-464
Due to the return of the beaver an increasing number of brooks become restored to a natural condition. It is characterized by an alternation of flowing and standing sectors. In the summer of 1995, different groups of organisms (Odonata, Mollusca, Trichoptera, Ephemeroptera, Diptera) of two brooks in the Spessart mountains (Hesse, Germany) were studied to compare the composition of invertebrates in beaver homeranges and in the non-influenced sectors above. The new living conditions resulted in the disappearance of some species (Drusus anulatus, Trich., Sericostoma personatum, Trich., Radix peregra, Gastr.). Nevertheless the beaver homeranges accommodate a significant higher number of species of dragon flies and damsel flies, molluscs and caddis flies than the brooks above the homeranges. The heterogeneity of natural river systems make a coexistence of running water and silent water organisms possible. The examinations result in a significant higher group dominance of ephemeras (i.p. Cloeon dipterum) in a beaver pond than in lenitic sectors conditioned by the gradient without beaver influence. Here the dominance of chironomids was much higher. High current sectors with their characteristic organisms are also present in the beaver homeranges. The higher number of insects is the basis of nourishment for predatory insects and fishes. The potential effects of beaver ponds on fishes are discussed. 相似文献
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<正>Three lepidopteran species,from the Middle Jurassic Daohugou beds(inner Mongolia,China),are described in a new family,Mesokristenseniidae,and new genus,Mesokristensenia,which could represent the sister group of the Micropterigidae.Mesokristensenia differs from all extant Lepidoptera,but one genus(Agathiphaga, Agathiphagidae),in retaining four median veins in the forewing,a plesiomorphy also present in many Trichoptera. Evidence for placing Mesokristensenia in the Lepidoptera includes four traits,notably a previously unrecorded autapomorphy of this insect order:beyond stem M1+2,vein M1 is bent and connected to cross-vein r-m(in both wing pairs).Among 24 characters taken into account to assess the systematic position of Mesokristensenia,12 are considered informative for a cladistic analysis involving this fossil taxon and the four suborders recognized in present-day Lepidoptera(Zeugloptera,Aglossata,Heterobathmiina,and Glossata). 相似文献
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The retreat-making larvae of many lotic caddisflies build entirely new pupal cases with fine gravel and sand that they collect in the neighbourhood of the building place to fix it with silk to cobbles in swift flow (where finer sediments are generally rare). Previous field observations on Hydropsyche siltalai pupal cases illustrate that natural local resource limitations of the preferred grain fraction (2.5–3.15 mm) produced chained effects across other grain fractions, as the alternative use of more grains in the 1.6–2 mm fraction (an unlimited resource) induced an increased use of more grains in the 0.315–0.5 mm fraction (another unlimited resource). To examine the implications of these observations for H. siltalai, we used (1) mesocosms to created minor deviations in the availability of the natural grain size composition of the building material of pupal cases at otherwise carefully replicated natural stream habitat conditions and (2) recently developed technologies to assess many case characteristics so far ignored in studies of caddisfly cases. When the preferred coarser grains (2.5–3.15 mm) were unavailable, more grains with intermediate size (1.25–2.0 mm) were used (and not other, still available coarse grains) and fewer larvae built cases in groups, thereby not only loosing the benefits (lower costs for grain transport and silk) but also avoiding potential disadvantages associated with grouped cases (more aggressive encounters with conspecifics for rare building material, less flow exposure and thus reduced water renewal in the pupal chamber). Unavailability of 2.5–3.15-mm and 0.315–0.5-mm grains caused a reduction of larvae building in groups, more use of grains with intermediate size, changes of several other grain characteristics (e.g. number, circularity) and considerable investment into silk to maintain the case resistance. Finally, grain availability deviating most from that observed in nature (no grains of 2.5–3.15 mm and 1.6–2.0 mm) caused dramatic responses, as mortality increased so that fewer pupal cases were built, using typically more coarse grains so that many cases had an elevated resistance against crushing forces; in addition, many males had a retarded development, whereas female development was unaffected. Thus, the response of H. siltalai to any of the three types of grain limitations differed, illustrating an immense diversity to respond to grain-size shortage. 相似文献
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Lake-outlets are transitional areas recognized as highly productive ecosystems in terms of density and biomass of aquatic insects. Life cycle, secondary production, trophic guilds and environmental constraints of caddisfly assemblages were investigated on a natural lake-outlet stream (Nant y Fall) in Patagonia, Argentina. We investigated the site monthly from May 2007 to April 2008 by recording environmental data and sampling caddis larvae using a Surber sampler at riffle areas (n = 36). Mastigoptila longicornuta, Smicridea annulicornis, Smicridea frequens, Brachysetodes quadrifidus and Parasericostoma ovale displayed well synchronized univoltine life cycles, while Neoatopsyche brevispina, Neopsilochorema tricarinatum, showed an asynchronous development pattern, although most of them had an extended recruitment, similar to those reported for non lake-outlet streams in the area. Annual secondary production per species varied from 8.22 (B. quadrifidus) to 3568.83 mg m−2 y−1 (P. ovale), with overall caddisfly production amounting to 4.8 g m−2 y−1. Shredder/collector-filterer ratio was 3.3/1 suggesting that the system was detrital based. Redundancy analysis indicated that seasonally dynamic variables such as discharge, benthic particulate organic matter and temperature were the main predictors of seasonal caddisfly assemblage variation. We propose that the variety of food resources and the significant spatial heterogeneity at lake-outlet streams contribute to sustain a rich caddisfly community. 相似文献