The first record of dicosmoecinae from the Cenozoic of the Russian Far East with a brief global overview of fossil Limnephilidae (Insecta: Trichoptera)

A new genus and species, Prodicos rasnitsyni gen. et sp. nov. (Trichoptera, Limnephilidae), from the Upper Eocene–Lower Oligocene of Russia is described. The global fossil record of adult Limnephilidae is reviewed.     

New insects (Insecta: Trichoptera,Eoblattida) from the Lower Permian of Russia

The insect fauna of the Lower Permian Tyulkino locality in the Perm Region of Russia is considered. New members of the orders Trichoptera and Eoblattida are described. Members of the primitive family Microptysmatidae (suborder Protomeropina) are typical of the Lower and Middle Permian deposits of Eurasia and are represented by the two genera: Microptysmella Kukalová-Peck et Willmann, 1990 and Kamopanorpa Martynov, 1928. Kamopanorpa tyulkiana sp. nov. and K. tamarae sp. nov. (Trichoptera, Microptysmatidae) and Parakhosara kamica sp. nov. (Eoblattida, Megakhosaridae) are described.     

Longitude variability of macrobenthos in the streams of Central European Russia

The changes in macrobenthos community depended on changes in stream discharge (from 0.001 m3/sec to 100 m3/sec) were studied on the basis of data from 254 stations of 180 streams located in the centre of European part of Russia. While discharge of stream increases community composition changes considerably. Species diversity increases from 12 to 47 species per station with the increase in stream size. Moreover, the diversity of almost all groups, discerned according habitat or trophic position and main taxonomic groups (with the exception of Plecoptera and Diptera) increases with the increase in stream discharge. The diversity of lithorheophilic species and species inhabiting soft substrates is higher in small streams, whereas phitophilic species are more diverse in large streams. With the increase in stream size the percent of algophagous and filter feeders increases, percent of carnivorous remains the same and the percent of detritophages decreases. The relative role of invertebrates macrotaxons change with the stream size: in the smallest streams the diversity is the highest among Diptera, Trichoptera and Plecoptera, in medium-size streams--among Trichoptera, Ephemeroptera and Diptera, in large streams--in Ephemeroptera, Gastropoda and Trichoptera. In some groups some species replace other (close-related) in parallel with change in stream discharge however in general this tendency is weak. The index of saprobic conditions increases with the increase in stream size from 1.6-1.7 to 2.3-2.4. In small streams the saprobic conditions are very different whereas large streams have tendency to be at beta-mesosaprobic level. Cluster analysis reveal four size classes of streams. Peculiarities of habitat and macrobenthos fauna of these classes are described.     

When phylogeny and ecology meet: Modeling the occurrence of Trichoptera with environmental and phylogenetic data

Ecological studies are increasingly considering phylogenetic relationships among species. The phylogeny is used as a proxy or filter to improve statistical tests and retain evolutionary elements, such as niche conservation. We used the phylogenetic topology to improve the model for occurrence of Trichoptera genera in Cerrado (Brazilian Savanna) streams. We tested whether parameters generated by logistic models of occurrence, using phylogenetic signals, are better than models generated without phylogenetic information. We used a model with Bayesian updating to examine the influence of stream water pH and phylogenetic relationship among genera on the occurrence of Trichoptera genera. Then, we compared this model with the logistic model for each Trichoptera genus. The probability of occurrence of most genera increased with water pH, and the phylogeny‐based explicit logistic model improved the parameters estimated for observed genera. The inferred relationship between genera occurrence and stream pH improved, indicating that phylogeny adds relevant information when estimating ecological responses of organisms. Water with elevated acidity (low pH values) may be restrictive for the occurrence of Trichoptera larvae, especially if the regional streams exhibit neutral to alkaline water, as is observed in the Cerrado region. Using phylogeny‐based modeling to predict species occurrence is a prominent opportunity to extend our current statistical framework based on environmental conditions, as it enables a more precise estimation of ecological parameters.     

Congruence of biodiversity measures among larval dragonflies and caddisflies from three Canadian rivers

1. Scientists tasked with collecting taxon richness and assemblage variation data for conservation purposes have identified biomonitoring studies as potential sources of information. This approach assumes that biodiversity patterns revealed by biomonitoring reflect those of the wider community, an assumption not thoroughly tested in riverine ecosystems. 2. We compared patterns of taxon richness and assemblage variation in an important biomonitoring group (Trichoptera) with a group with high conservation significance (Odonata) at 34 sites across three fifth‐order catchments. We also explored the effect of abundance on observed patterns by rarefying the larval Trichoptera data set. 3. Our results indicate that Trichoptera do not fully reflect site‐scale taxon richness or assemblage variation in Odonata. The magnitude of odonate assemblage variation was much greater than that of Trichoptera for one of the catchments. Odonata and Trichoptera richness was moderately correlated in two catchments, while assemblage variation was strongly correlated in another pair of catchments. However, comparisons based on rarefied data eliminated differences in the magnitude of assemblage variation and strengthened correlations in richness and assemblage variation, suggesting the lack of congruence in these measures might be due to differences in abundance among groups. Further, incomplete taxonomy may mask additional assemblage variation, particularly in Trichoptera. 4. Conservation planning in riverine ecosystems based on proxies derived from biomonitoring data should proceed cautiously until we understand how well the resulting information reflects biodiversity patterns in under‐sampled taxa and habitats. Future studies of biodiversity congruence should consider both richness and assemblage variation as each provides valuable information for conservation‐related decisions. The taxonomic resolution and relative abundance of comparison groups can potentially impact the strength, direction and statistical significance of patterns. Researchers should employ species‐level taxonomy and account for differences in abundance among groups through rarefaction where at all possible and DNA‐based taxonomy methods can support this.     

Global diversity of caddisflies (Trichoptera: Insecta) in freshwater

The not yet uploaded Trichoptera World Checklist (TWC) [], as at July 2006, recorded 12,627 species, 610 genera and 46 families of extant and in addition 488 species, 78 genera and 7 families of fossil Trichoptera. An analysis of the 2001 TWC list of present-day Trichoptera diversity at species, generic/subgeneric and family level along the selected Afrotropical, Neotropical, Australian, Oriental, Nearctic and Palaearctic (as a unit or assessed as Eastern and Western) regions reveals uneven distribution patterns. The Oriental and Neotropical are the two most species diverse with 47–77% of the species in widespread genera being recorded in these two regions. Five Trichoptera families comprise 55% of the world’s species and 19 families contain fewer than 30 species per family. Ten out of 620 genera contain 29% of the world’s known species. Considerable underestimates of Trichoptera diversity for certain regions are recognised. Historical processes in Trichoptera evolution dating back to the middle and late Triassic reveal that the major phylogenetic differentiation in Trichoptera had occurred during the Jurrasic and early Cretaceous. The breakup of Gondwana in the Cretaceous led to further isolation and diversification of Trichoptera. High species endemism is noted to be in tropical or mountainous regions correlated with humid or high rainfall conditions. Repetitive patterns of shared taxa between biogeographical regions suggest possible centres of origin, vicariant events or distribution routes. Related taxa associations between different regions suggest that an alternative biogeographical map reflecting Trichoptera distribution patterns different from the Wallace (The Geographical Distribution of Animals: With a Study of the Relations of Living and Extinct Faunas as Elucidating the Past Changes of the Earth’s Surface, Vol. 1, 503 pp., Vol. 2, 607 pp., Macmillan, London, 1876) proposed biogeography patterns should be considered. Anthropogenic development threatens biodiversity and the value of Trichoptera as important functional components of aquatic ecosystems, indicator species of deteriorating conditions and custodians of environmental protection are realised.     

The influence of different spatial‐scale variables on caddisfly assemblages in Flemish lowland streams

1. Patterns in species assemblages are the result of the combined influence of processes acting on different spatial scales. Various studies describe the distribution of macroinvertebrate communities and their relationship with environmental factors at different geographical scales, but only a few of these studies concentrate on Western European lowlands. 2. Using Flanders as representative for the densely populated Western‐European lowlands, the specific aims of this study are: (i) to identify the different trichopteran species assemblages and to characterise them biologically using indicator species; (ii) to determine which environmental gradients most influence the observed species assemblages; and (iii) to analyse the relative importance of different spatial scale variables in constraining the Trichoptera distributions. 3. Assessment of the main environmental gradients suggested that the absence of Trichoptera from certain locations was mainly due to elevated nutrient concentrations and lower oxygen contents, confirming their sensitivity to anthropogenic disturbance. 4. Five Trichoptera species assemblages were distinguished based on Bray–Curtis dissimilarity coefficients. These assemblages did not differ significantly in species richness, but a shift in stream zonation preference was observed. In the ordination analysis 11 variables that were selected using a stepwise model building function manifested themselves as upstream–downstream and size‐related gradients. The Trichoptera assemblages in lowland streams thus appear to follow a longitudinal succession pattern that corresponds with the species‐specific preferences. 5. Partitioning the variance over the different spatial scales indicated that the reach‐scale variables were far more important in explaining the variation in species composition. The study design, which limited the minimum–maximum range of catchment‐scale characteristics, however, may have led to an overestimation of the impact of the local‐scale variables.     

Massive gene rearrangements of mitochondrial genomes and implications for the phylogeny of Trichoptera (Insecta)

Mitochondrial genomes have been widely used for phylogenetic reconstruction and evolutionary analysis in various groups of Insecta. Gene rearrangements in the mitogenome can be informative characters for phylogenetic reconstruction and adaptive evolution. Trichoptera is one of the most important groups of aquatic insects. Prior to this study, complete mitogenomes from Trichoptera were restricted to eight families, resulting in a biased view of their mitogenome structure and evolution. Here, we assemble new mitogenomes for 66 species by high-throughput sequencing. The mitogenomes of 19 families and 47 genera are documented for the first time. Combined with 16 previously published mitogenomes of Trichoptera, we find 14 kinds of gene rearrangement patterns novel for Trichoptera, including rearrangement of protein-coding genes, tRNAs and control regions. Simultaneously, we provide evidence for the occurrence of tandem duplication and non-random loss events in the mitogenomes of three families. Phylogenetic analyses show that Hydroptilidae was recovered as a sister group to Annulipalpia. The increased nucleotide substitution rate and adaptive evolution may have affected the mitochondrial gene rearrangements in Trichoptera. Our study offers new insights into the mechanisms and patterns of mitogenome rearrangements in Insecta at large and into the usefulness of mitogenomic gene order as a phylogenetic marker within Trichoptera.     

Sex chromatin and sex chromosome systems in nonditrysian Lepidoptera (Insecta)

Eleven representatives of the superorder Amphiesmenoptera (Trichoptera + Lepidoptera) were examined for sex chromatin status. Three species represent stenopsychoid, limnephiloid and leptoceroid branches of the Trichoptera; eight species belong to the primitive, so-called nonditrysian Lepidoptera and represent the infra-orders Zeugloptera, Dacnonypha, Exoporia, Incurvariina, Nepticulina and Tischeriina. The female-specific sex chromatin body was found in the interphase somatic nuclei of Tischeria ekebladella (Bjerkander 1795) (Lepidoptera, Tischeriina). The sex chromatin was absent in all investigated Trichoptera species as well as in all representatives of the nonditrysian Lepidoptera except Tischeria ekebladella . The sex chromosome mechanism of Limnephilus lunatus Curtis 1834 (Trichoptera, Limnephilidae) is Z/ZZ. The sex chromosome mechanism of Tischeria ekebladella (Lepidoptera, Tischeriina) is ZW/ZZ including the W chromosome as the largest element in the chromosome set. The data obtained support the hypothesis that the Z/ZZ sex chromosome system, the female heterogamety and the absence of the sex chromatin body in interphase nuclei are ancestral traits in the superorder Amphiesmenoptera. These ancestral characters are probably kept constant in all the Trichoptera and in the most primitive Lepidoptera. The W sex chromosome and the sex chromatin evolved later in the nonditrysian grade of the Lepidoptera. It is proposed that the sex chromatin is a synapomorphy of Tischeriina and Ditrysia.     

A multigene phylogeny and timeline for Trichoptera (Insecta)

The Trichoptera, or caddisflies, are traditionally split into two taxonomic subdivisions: the ‘retreat-making’ Annulipalpia and the ‘case-making’ Integripalpia (sensu Ross). The monophyly of these groups is well documented; however, the establishment of a third subdivision, ‘Spicipalpia’, and the positions of the five ‘spicipalpian’ families is much debated. In contrast to previous molecular studies using nuclear ribosomal RNA, a recent trichopteran study (using nuclear protein-coding genes) placed one of these ‘spicipalpian’ families, the free-living predatory Rhyacophilidae, as the sister taxon to the rest of Trichoptera, a result that has significant implications for both the understanding of trichopteran evolution and its timing. This paper sets out to investigate the relationships of Trichoptera using several newly sequenced genes, together with previously published gene sequences. This dataset is the largest trichopteran dataset to date, covering six independent genes and > 10 000 nucleotides, and containing 185 species representing 49 families. With all data included, likelihood and Bayesian analyses support a monophyletic Annulipalpia and a monophyletic Integripalpia, which includes the ‘spicipalpians’ as a paraphyletic grade at the base of this clade. However, an analysis of the protein-coding data alone using similar analytical methods recovers Rhyacophilidae as the most basal taxon in Trichoptera, with low support. A reanalysis correcting for nucleotide composition bias provides support for the placement of the ‘spicipalpian’ taxa as sister to the Integripalpia, consistent with the total data analysis, suggesting that the basal position of Rhyacophilidae in the uncorrected analysis could be (or is probably) an artefact of base composition. We find it likely that ancestral trichopterans made incipient cases and retreats, and these had independent origins as precocious pupal chambers. Molecular dating analysis in beast , using the birth-death model of speciation, with a relaxed-clock model of sequence evolution informed by 37 fossil constraints, suggests that the most recent common ancestor of Trichoptera appeared in the Permian (c. 275 Ma) in line with the first appearance of Trichoptera in the fossil record, and that vicariance explains the distribution of most trichopteran taxa. A new infraordinal name, Phryganides , is introduced for the tube-case-making families of Integripalpia.     

The evolutionary history of Trichoptera (Insecta): A case of successful adaptation to life in freshwater

The insect order Trichoptera (caddisflies) forms the second most species‐rich monophyletic group of animals in freshwater. So far, several attempts have been made to elucidate its evolutionary history with both morphological and molecular data. However, none have attempted to analyse the time frame for its diversification. The order is divided into three suborders – Annulipalpia, Integripalpia and ‘Spicipalpia’. Historically, the most problematic taxon to place within the order is ‘Spicipalpia’, whose larvae do not build traditional cases or filtering nets like the majority of the caddisflies. They have previously been proposed to be the sister group of all other Trichoptera or more advanced within the order, with equivocal monophyly and with different interordinal placements among various studies. In order to resolve the evolutionary history of the caddisflies as well as timing their diversification, we utilized fragments of three nuclear (carbamoylphosphate synthethase, isocitrate dehydrogenase and RNA polymerase II) and one mitochondrial (cytochrome oxidase I) protein coding genes, with 16 fossil trichopteran taxa used for time calibration. The ‘spicipalpian’ families are recovered as ancestral to all other caddisflies, though paraphyletic. We recover stable relationships among most families and superfamilies, resolving many previously unrecognized phylogenetic affinities amongst extant families. The origin of Trichoptera is estimated to be around 234 Ma, i.e. Middle – Late Triassic.     

Scale-dependence of the correlation between human population and the species richness of stream macro-invertebrates

Recent biogeographical studies have shown positive correlations between plant/vertebrate species richness and human population presence. The same pattern has been reported for Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies) (EPT) amongst European countries. This is surprising as EPT are bio-indicators of stream pollution and most local studies report higher species richness of these macro-invertebrates where human influences on water quality are lower. Using a newly collated taxonomic dataset, we studied whether the species richness of EPT is related to human population size at finer resolutions (Italy's regions, provinces and 10×10 km² UTM cells) controlling for sampling effort, variations in area and for spatial autocorrelation. At all study grains, observed EPT species richness was strongly correlated to the number of records available for the same taxon. At the regional level, the observed number of Ephemeroptera and Plecoptera species significantly increased with increasing human population size. At the provincial level, observed species richness decreased significantly with increasing human population size for Ephemeroptera and did not vary significantly for Plecoptera and Trichoptera. At the finest grain scale, there were significant negative correlations of observed Ephemeroptera and Trichoptera species richness with human population size, although the proportion of variance explained was very low. These results were broadly confirmed when analyzing the estimated number of species using the formula of Chao2. Our analysis confirms the scale-dependence of the human population–biodiversity correlation. Over broad scales more populated regions tend to have more species than less populated ones. Restricting the study grain, the positive EPT species–people relationship disappears and turns into a negative one. Our findings suggest a challenge also for the conservation of regional EPT diversity.     

Exploring a key synapomorphy: correlations between structure and function in the sternum V glands of Trichoptera and Lepidoptera (Insecta)

The sternum V glands are a key synapomorphy that unites Trichoptera with Lepidoptera, but their functional aspects have not been analysed from an evolutionary perspective. We examine phylogenetic trends and correlations between chemical and morphological features of these glands. The most likely ancestral gland compounds are heptan‐2‐ol, 4‐hepten‐2‐one and ‐ol, nonan‐2‐one, and 6‐nonen‐2‐one and ‐ol, making pheromone production a plausible ancestral function. The most widespread gland compounds (heptan‐2‐one and ‐ol and nonan‐2‐one and ‐ol) are not known from Apataniidae + Limnephilidae (Trichoptera), which in turn uniquely produce a number of methylated 3‐ketones and their corresponding alcohols, probably functioning as pheromones. We propose a functional connection between perforated patches on sternum IV in females and a scaly/dome‐covered area around the gland openings, as well as between perforated patches and lack of Trichoptera‐type opening muscles. We also propose a functional connection between the shape of the gland reservoirs and the presence of gland reservoir musculature. The perforated patches were significantly correlated with several gland compounds that had double bonds between carbon atoms: the double bonds may lower the viscosity of the compounds, facilitating secretion through the tiny pores of the perforated patches. The production of defensive substances in Pycnopsyche (Trichoptera: Limnephilidae) is probably connected to the presence of large, compartmentalized gland reservoirs. Large glands in male Hydropsyche (Trichoptera: Hydropsychidae) are probably linked to male aggregation pheromone production. The relative sizes of sternum V gland reservoirs and fenestral gland reservoirs in female philopotamids (Trichoptera) suggest a complementary function of the two structures. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 561–579.     

A comparative morphological study of lateral line systems in larvae and pupae of Trichoptera

The abdominal lateral line system in Trichoptera, consisting of filaments and lamellae with associated primary and secondary setae, was studied in larvae and pupae of 70 genera representing 26 families. Filaments are slender, generally bifid, tubular extensions of the cuticle that together form a fringe on the lateral abdominal surface of larvae and pupae of many but not all families of case-making Trichoptera (Integripalpia). Larvae and pupae of the Annulipalpia and Spicipalpia lack a lateral fringe of bifid filaments, but single filaments occur in larvae of a few unrelated genera. A lateral fringe may help in regulating the flow of water which is maintained through the case by abdominal undulation. Lamellae occur only in larvae of the Integripalpia, where they are variously distributed among families and genera, and probably have a sensory function. Three types of lamellae are recognized: forked, serrate and single. Filaments and lamellae have significant taxonomic value, and their patterns of occurrence raise questions about the phylogeny of Trichoptera.     

Problems of Russian dendrology in the XXI century

The latest analysis of the state of dendrological studies in Russia was carried out by V. N. Sukachev in 1921 and published in the Proceedings of the All-Russian Forest Conference. Over the past 83 years, many new botanic gardens have been created (in Russia they are over 80), and dendrological studies in many biological institutes and universities have been enlarged. Dendrologists have been faced with new challenges related to the development of eastern regions of Russia and the need for a comprehensive study and conservation of the gene pool of woody plants in nature and culture. The present paper deals with problems that should be addressed in the first place and in the longer term. Particular attention is paid to the introduction of woody plants from different botanical-geographical areas of Eurasia and North America to Russia, and modern notions of the state of the native woody flora of Siberia and the Far East are analyzed in connection with the solution of the global problem of studying and conserving the vegetation biodiversity of Russia. The paper is concluded with a list of the main challenges facing dendrologists which, in the author’s opinion, should be taken into account when planning dendrological studies in various regions of Russia.     

毛翅目化石研究进展

本文详细总结和回顾了世界毛翅目化石研究简史,列出已发表的化石种类名录、分布及年代,共37科、193属、661种(包括中国发现的4科9属15种),描述了不同地质时期主要毛翅目化石的分类单元和分布地区。简要介绍了毛翅目分类系统及系统发育、不同地质时期毛翅目化石的产地及时代。初步分析了目前该类群所存在的一些问题,并对今后的研究工作进行了展望。     

Caddisflies from Cenozoic resins of Europe

Analysis of the available data on the findings and taxonomical structure of caddisflies (Insecta, Trichoptera) in the Cenozoic fossil resins of Europe shows that there are four European amber regions (Baltic, Rovno, Saxonian, and Danish) are characterized by a relatively abundant trichopteran fauna, comprising 27 families, 72 genera, and 256 species. These faunas show the dominance of Psychomyioidea (families Polycentropodidae, Psychomyiidae, and Ecnomidae) with Polycentropodidae comprising up to 75% of all records. The amber faunas are second in the dominance of Polycentropodidae only to the terminal Eocene of Florissant (84% of Polycentropodidae). No modern caddisfly species have been found. The amber regions are significantly different in the species composition of Trichoptera although the generic and family structures are similar. Comparison with the modern faunas of Europe shows the absence of advanced Limnephilidae, which are characteristic of the Holocene faunas of Europe, and the rarity of recently abundant Hydropsychidae and Hydroptilidae. The overall composition of amber Trichoptera suggests that it is structurally related to the faunas of Caucasus and Southeastern Asia and might be evidence of seasonally low-contrast (equable) climate in the Late Eocene of Europe.     

Wing-scales of Pseudoleptocerus chirindensis Kimmins (Trichoptera: Leptoceridae)

The African species Pseudoleptocerus chirindensis belongs to a small group of Trichoptera most unusual in having scaly wings. Electron microscope studies reveal 13 structurally distinct kinds of cuticular process on the wings, including several types of squamiform and hair-like macrotrichia. These are described in detail and their possible functions inferred. The optical properties of the scales forming the colour pattern of the forewings are related to ultrastructural elements including diffraction and thin film interference systems. Trirhopteran scale structure is compared with that of the Lepidoptera, the sister-group in the Amphiesmenoptera. Differences are found and it is tentatively concluded that wing-scales have evolved independently in the two orders.     

Silk tape nanostructure and silk gland anatomy of trichoptera

Caddisflys (order Trichoptera) construct elaborate protective shelters and food harvesting nets with underwater adhesive silk. The silk fiber resembles a nanostructured tape composed of thousands of nanofibrils (～ 120 nm) oriented with the major axis of the fiber, which in turn are composed of spherical subunits. Weaker lateral interactions between nanofibrils allow the fiber to conform to surface topography and increase contact area. Highly phosphorylated (pSX)(4) motifs in H-fibroin blocks of positively charged basic residues are conserved across all three suborders of Trichoptera. Electrostatic interactions between the oppositely charged motifs could drive liquid-liquid phase separation of silk fiber precursors into a complex coacervates mesophase. Accessibility of phosphoserine to an anti-phosphoserine antibody is lower in the lumen of the silk gland storage region compared to the nascent fiber formed in the anterior conducting channel. The phosphorylated motifs may serve as a marker for the structural reorganization of the silk precursor mesophase into strongly refringent fibers. The structural change occurring at the transition into the conducting channel makes this region of special interest. Fiber formation from polyampholytic silk proteins in Trichoptera may suggest a new approach to create synthetic silk analogs from water-soluble precursors.