Diversity and Ecosystem Services of Trichoptera

The Collapsible Light Trap: a portable Pennsylvania Light Trap for collecting aquatic insects

A Collapsible Light Trap (CLT) for collecting insects, particularly aquatic insects, is described here. CLT is a modified Pennsylvania Light Trap with the advantage of being collapsible and lightweight to be carried in a small backpack and very easy to set up in the field. CLT is equipped with LED light strip wrapped around a PVC tube and can be connected to a regular 12 V / 7 Ah battery, running for more than 48 uninterrupted hours. Complete CLT weighs 0.8-1.0 kg, depending on the metal used, and the battery weighs around 2 kg, being easily transportable to more remote collecting areas. Over the years, CLTs have been used for collecting and describing the diversity of aquatic insects from Brazil, particularly caddisflies. Depending on the locality, only one trap for one night can collect over a thousand insect specimens and more than 200 individuals of caddisflies.

Phylogenomics recovers multiple origins of portable case making in caddisflies (Insecta: Trichoptera), nature's underwater architects

Caddisflies (Trichoptera) are among the most diverse groups of freshwater animals with more than 16 000 described species. They play a fundamental role in freshwater ecology and environmental engineering in streams, rivers and lakes. Because of this, they are frequently used as indicator organisms in biomonitoring programmes. Despite their importance, key questions concerning the evolutionary history of caddisflies, such as the timing and origin of larval case making, remain unanswered owing to the lack of a well-resolved phylogeny. Here, we estimated a phylogenetic tree using a combination of transcriptomes and targeted enrichment data for 207 species, representing 48 of 52 extant families and 174 genera. We calibrated and dated the tree with 33 carefully selected fossils. The first caddisflies originated approximately 295 million years ago in the Permian, and major suborders began to diversify in the Triassic. Furthermore, we show that portable case making evolved in three separate lineages, and shifts in diversification occurred in concert with key evolutionary innovations beyond case making.

Diversity and Flight Patterns of Caddisflies (Trichoptera) in an Atlantic Forest Fragment: Implications for Species Conservation in Threatened Ecosystems

Anthropogenic activities have decimated the Atlantic Forest domain (AF) and increased the pressure on freshwater biota, such as Trichoptera, which is the most affected order by the current insect decline. Adult mobility is crucial for the colonisation of new environments unconnected by water sources. In this article, we describe the assemblage of caddisflies in a preserved AF fragment related to their functional feeding group and provide empirical data on the patterns of horizontal and vertical flight. Adults were collected using white sheet and light attraction traps, placed at different distances and heights from a stream in Pernambuco, Brazil. A total of 2934 specimens of 15 species from five families were collected, mostly collector-filterers. Horizontal flight was limited, with 80% of the abundance concentrated up to 20 m. Vertical stratification was also concentrated at lower heights. A female-biased proportion was observed at higher strata. The richness and abundance of species decreased with increasing distances and heights from the stream. Overall, Chimarra sp. and Macrostemum scharfi were the dominant species. Trichoptera is a key taxon used as a biological indicator of water quality, and here, knowledge on the diversity and flight patterns of adults is expanded. At the risk of intensive pollution of rivers in Atlantic forests, data on the adult dispersal can be incorporated in the assessment of endangerment status and in conservation strategies.

Mining tailings alter insects: revealing fluctuating asymmetry in the caddisfly Smicridea coronata

The Samarco/Vale/BHP mine tailing dam breach that took place in Minas Gerais, southeastern Brazil, in 2015, deposited high concentrations of metals and metalloids in the Rio Doce basin, severely impacting freshwater and riverine forest ecosystems. To assess developmental instability of caddisflies in response to the environmental impacts of the dam breach, we investigated the fluctuating asymmetry (FA) in the species Smicridea (Rhyacophylax) coronata (Trichoptera: Hydropsychidae). FA was assessed at individual and populational scales using geometric morphometric methods in the cephalic capsule and mandibles of larvae and also on the forewings of adults, both collected under the impacted condition, and under the least disturbed condition. The levels of FA increased in response to stressors on the forewings at the populational scale, and on the mandibles, at individual scale. These morphological variations in the larval and adult stages may lead to detrimental effects and result in high mortality rates as well as lower adult fitness. Trichoptera forewings are revealed as suitable traits for assessing FA, holding potential for applications in biomonitoring programs. Directional asymmetry levels were higher than FA levels for all traits, and this correlation could be explained by a transition from fluctuating to directional asymmetry in the presence of heightened disturbance. Our results validate the relationship between the impacts from the dam breach and increased developmental instability in this species with likely cascade effects on the insect community.

Helicopsyche (Feropsyche) Johanson, 1998 (Trichoptera) from Northeastern Mata Atlântica Freshwater ecoregion: integrating taxonomy and niche modeling

The Northeastern Mata Atlântica Freshwater ecoregion (NMAF) is part of the 25 worlds biodiversity hotspots. It comprises the Central Atlantic Forest Ecological Corridor and Chapada Diamantina Complex (in part), including high rates of endemism in coastal freshwater ecosystems. However, estimates indicate a high population decline in Freshwater ecosystems. Trichoptera are the most affected insect order, with average extinction rates of ~9% and many unknown species (e.g., estimates are around 50% in Brazil and Ecuador). This crisis can be aggravated by gaps in the knowledge of species (Linnean shortfall) and their distribution (Wallacean shortfall), caused mainly by a lack of investment in extensive fauna inventories and human resources related to systematics. Thus, to face these shortfalls in NMAF, we describe four new species of. H. (Feropsyche) and provide new distribution records. In addition, we perform niche modeling based on the species distributions of the group to identify areas with high environmental suitability to direct biodiversity research efforts on NMAF, a highly endemic and underexplored ecoregion. We increased the number of known species of NMAF from seven to 16 species. The niche modeling pointed to two areas as priorities to guide the strategies to reduce shortfalls in the NMAF.

Chromosome-scale genome assemblies of Himalopsyche anomala and Eubasilissa splendida (Insecta: Trichoptera)

Trichoptera is one of the most evolutionarily successful aquatic insect lineages and is highly valued value in adaptive evolution research. This study presents the chromosome-level genome assemblies of Himalopsyche anomala and Eubasilissa splendida achieved using PacBio, Illumina, and Hi-C sequencing. For H. anomala and E. splendida, assembly sizes were 663.43 and 859.28 Mb, with scaffold N50 lengths of 28.44 and 31.17 Mb, respectively. In H. anomala and E. splendida, we anchored 24 and 29 pseudochromosomes, and identified 11,469 and 10,554 protein-coding genes, respectively. The high-quality genomes of H. anomala and E. splendida provide critical genomic resources for understanding the evolution and ecology of Trichoptera and performing comparative genomics analyses.

Morphology of the male reproductive system and spermatozoa of Smicridea (Rhyacophylax) iguazu Flint, 1983 (Trichoptera, Hydropsychidae)

The Trichoptera, holometabolous aquatic insects found worldwide except in Antarctica, exhibit a unique feature in their sperm, which are solely nucleated (eupyrene). Current knowledge on Trichoptera sperm is limited to Old World species. To enhance our understanding of their reproductive biology and contribute to systematic discussions, we describe the male reproductive system and spermatozoa of Smicridea (Rhyacophylax) iguazu Flint, 1983 (Hydropsychidae). This species lacks seminal vesicles, possesses piriform to oval-shaped testes with spermatozoa grouped in apical bundles and dense filamentous material filling other areas. The vasa deferentia are long and a pair of elongated accessory glands displays distinct proximal and distal regions. The relatively short (∼40 μm) spermatozoa are nucleated, aflagellated, and immobile. Further research could explore variations and assess the taxonomic utility of these features for genus identification within Hydropsychidae.

Mandible mechanical properties and composition of the larval Glossosoma boltoni (Trichoptera, Insecta)

Insect feeding structures, such as mandibles, interact with the ingesta (food or/and substrate) and can be adapted in morphology, composition of material and mechanical properties. The foraging on abrasive ingesta, as on algae covering rocks, is particularly challenging because the mandibles will be prone to wear and structural failure, thus suggesting the presence of mandibular adaptations to accompany this feeding behavior. Adaptations to this are well studied in the mouthparts of molluscs and sea urchins, but for insects there are large gaps in our knowledge. In this study, we investigated the mandibles of a grazing insect, the larvae of the trichopteran Glossosoma boltoni. Using scanning electron microscopy, wear was documented on the mandibles. The highest degree was identified on the medial surface of the sharp mandible tip. Using nanoindentation, the mechanical properties, such as hardness and Young's modulus, of the medial and lateral mandible cuticles were tested. We found, that the medial cuticle of the tip was significantly softer and more flexible than the lateral one. These findings indicate that a self-sharpening mechanism is present in the mandibles of this species, since the softer medial cuticle is probably abraded faster than the harder lateral one, leading to sharp mandible tips. To investigate the origins of these properties, we visualized the degree of tanning by confocal laser scanning microscopy. The autofluorescence signal related to the mechanical property gradients. The presence of transition and alkaline earth metals by energy dispersive X-ray spectroscopy was also tested. We found Ca, Cl, Cu, Fe, K, Mg, Mn, P, S, Si, and Zn in the cuticle, but the content was very low and did not correlate with the mechanical property values.

Fossils in Myanmar amber demonstrate the diversity of anti-predator strategies of Cretaceous holometabolan insect larvae

Holometabolan larvae are a major part of the animal biomass and an important food source for many animals. Many larvae evolved anti-predator strategies and some of these can even be recognized in fossils. A Lagerstätte known for well-preserved holometabolan larvae is the approximately 100-million-year-old Kachin amber from Myanmar. Fossils can not only allow to identify structural defensive specializations, but also lifestyle and even behavioral aspects. We review here the different defensive strategies employed by various holometabolan larvae found in Kachin amber, also reporting new cases of a leaf-mining hymenopteran caterpillar and a hangingfly caterpillar with extensive spines. This overview demonstrates that already 100 million years ago many modern strategies had already evolved in multiple lineages, but also reveals some cases of now extinct strategies. The repetitive independent evolution of similar strategies in distantly related lineages indicates that several strategies evolved convergently as a result of similar selective pressures.

Seven new species and four new records of Psychomyiidae (Insecta, Trichoptera) from China

Seven new species of the family Psychomyiidae Walker, 1852 are described and illustrated from China; they are Psychomyiashunisp. nov., Ps.mangshanensissp. nov., Ps.capricornissp. nov., Lypesagittalissp. nov., Paduniellafasciariasp. nov., Pa.sanyaensissp. nov., and Tinodesaviformissp. nov. The genus Lype is reported for the first time from mainland China. In addition, four psychomyiids are found to be new to the Chinese caddis fauna: Psychomyiaindra Malicky & Chantaramongkol, 1993; Paduniellaandamanensis Malicky, 1979; Pa.dendrobia Malicky & Chantaramongkol, 1993; and Tinodesgapbona Johanson & Oláh, 2008. Moreover, Psychomyiapolyacantha Li, Qiu & Morse, 2021 is reviewed and synonymized with Psychomyiaimamiah Malicky, 2020.

Diversity of Leptoceroidea (Insecta: Trichoptera) in Par State, Brazil: A new species of Oecetis McLachlan 1877 and new records

The order Trichoptera contains approximately 17,250 described species and their individuals are important freshwater environment components, frequently used as bioindicators of environmental quality. Despite recent advances in the knowledge of caddisflies in the Neotropical region, there are gaps to be filled, especially in critically endangered biomes, such as the Amazon rainforest, which has its largest area in the North Region of Brazil. In this region of Brazil, the state of Par presents a promising scenario for biodiversity studies, since a great portion of its area is covered by the Amazon rainforest and distinct environments (e.g., mangroves and rainforest). Knowledge about Trichoptera in the state includes 97 species records, 12 of them belonging to Leptoceroidea. To improve knowledge regarding the Amazon fauna, we record nine species of Leptoceroidea for the first time in Par State: Marilia alata, Nectopsyche muhni, Nectopsyche multilineata, Oecetis bidigitata, Oecetis cassicoleata, Oecetis doesburgi, Oecetis iguazu, Phylloicus auratus, and Triplectides maranhensis; we also describe and illustrate one new species: Oecetis ancorospina n. sp. which belongs to the Oecetis testacea Species Group.

Caddisflies (Trichoptera) of Protected Calcareous Fen Habitats: Assemblages, Environmental Drivers, Indicator Species, and Conservation Issues

The caddisflies (Trichoptera) of calcareous fen habitats, in contrast to those of other peatland types, have been poorly researched. We thus conducted a two-year study in south-eastern Poland encompassing four types of such habitats-drained and undrained fens and water bodies (pools and ditches) located within the fens-in order to define trichopteran reference assemblages (PCoA), indicator species (IndVal analysis), and the drivers (both natural and those associated with landscape management, including area protection) responsible for caddisfly species distribution (CCA). The most important environmental driver was habitat persistence. Distance-based RDA analysis revealed a distinct pattern in the distribution of species with or without diapause along the persistence gradient. Environmental drivers associated with plants were also crucial for both fens and water bodies. The key factor influencing the caddisfly assemblages of pools and ditches was the use and management of the surrounding land, whereas in the fens, it was the level of area protection. Physical and chemical water parameters had no statistically significant impact on the assemblages. Some factors can be modified by humans (e.g., water level regulation, vegetation, and landscape management) to maintain healthy ecosystems for aquatic insects.

Transcriptomic sequencing data illuminate insecticide-induced physiological stress mechanisms in aquatic non-target invertebrates

Pesticides are major agricultural stressors for freshwater species. Exposure to pesticides can disrupt the biotic integrity of freshwater ecosystems and impair associated ecosystem functions. Unfortunately, physiological mechanisms through which pesticides affect aquatic organisms are largely unknown. For example, the widely-used insecticide chlorantraniliprole is supposed to be highly selective for target pest species, i.e. Lepidoptera (butterflies), but its effect in aquatic non-target taxa is poorly studied. Using RNA-sequencing data, we quantified the insecticide effect on three aquatic invertebrate species: the caddisfly Lepidostoma basale, the mayfly Ephemera danica and the amphipod Gammarus pulex. Further, we tested how the insecticide-induced transcriptional response is modulated by biotic interaction between the two leaf-shredding species L. basale and G. pulex. While G. pulex was only weakly affected by chlorantraniliprole exposure, we detected strong transcriptional responses in L. basale and E. danica, implying that the stressor receptors are conserved between the target taxon Lepidoptera and other insect groups. We found in both insect species evidence for alterations of the developmental program. If transcriptional changes in the developmental program induce alterations in emergence phenology, pronounced effects on food web dynamics in a cross-ecosystem context are expected.

Taxonomic diversity of Ochrotrichiinae (Trichoptera: Hydroptilidae) from Peru with the description of ten new species, a new distributional record, and an updated checklist

We describe here ten new species of Ochrotrichiinae from southern Peru in genera Metrichia (7 new species), Ochrotrichia (1 new species), and Rhyacopsyche (2 new species). In addition to describing and illustrating male genitalia of the new species, we also highlight diagnostic features from antennae, head setal warts, and wing venation. These structures have received little attention in taxonomic studies of Hydroptilidae, and we think they may be useful in future morphological studies involving the family. We also record O. puyana for the first time from Peru, which was previously known only from Ecuador. Comments on the distribution of the Peruvian Ochrotrichiinae are also provided, along with a distributional map and an updated checklist of the species recorded in the country. This work revealed a total of 56 species of Ochrotrichiinae from Peru.

Brevitentoria Weaver 1984 (Trichoptera: Integripalpia) of Esprito Santo State, Brazil: New records and new species

In Brazil, about 900 species of Trichoptera have been recorded, with some species in all Brazilian states. Nevertheless, the collection effort is unequal, with several under-sampled regions. Despite being located entirely within the Atlantic Forest ecoregion, a hotspot of biodiversity, Esprito Santo State has a low known caddisfly richness when compared to nearby areas in the same ecoregion, especially for the infraorder Brevitentoria. This suggests the existence of a Trichoptera biodiversity knowledge gap. Aiming to overcome these taxonomic and distributional shortfalls, we performed a comprehensive inventory of the Brevitentoria species in the state. The sampled sites were distributed from North to South of the state covering 22 locations. In total, 3,420 adult specimens of Brevitentoria were analyzed, leading to a total of 40 species. Two families and 27 species are recorded for the first time from the state. Additionally, we describe three new species of the genera Phylloicus, Helicopsyche (Feropsyche), and Marilia. As a result of this survey, we increase by 100% the number of species of Brevitentoria known from the state, and by 30% for the number of known Trichoptera species. Based on incidence data from this inventory and from the literature, the Brevitentoria species richness was estimated to be about 72 species in Esprito Santo State.

Characterization of the primary structure of the major silk gene, h-fibroin, across caddisfly (Trichoptera) suborders

Larvae of caddisflies (Trichoptera) produce silk to build various underwater structures allowing them to exploit a wide range of aquatic environments. The silk adheres to various substrates underwater and has high tensile strength, extensibility, and toughness and is of interest as a model for biomimetic adhesives. As a step toward understanding how the properties of underwater silk evolved in Trichoptera, we used genomic data to identify full-length sequences and characterize the primary structure of the major silk protein, h-fibroin, across the order. The h-fibroins have conserved termini and basic motif structure with high variation in repeating modules and variation in the percentage of amino acids, mainly proline. This finding might be linked to differences in mechanical properties related to the different silk usage and sets a starting point for future studies to screen and correlate amino acid motifs and other sequence features with quantifiable silk properties.

Description of the larva of Macrostemum floridum (Navás 1929) (Trichoptera: Hydropsychidae) and its feeding habits in Kaengkrung National Park, southern Thailand

A morphological description of the last (fifth) instar larva of Macrostemum floridum (Navás 1929), its life cycle, and feeding habits are provided. The study was conducted along the Khlong Yan Stream in Kaengkrung National Park, southern Thailand. Larval identification was achieved by the metamorphotype method of associating immature stages with the adult. A graph of head capsule widths for all instars is provided. Gut content analysis showed that the main food items were diatoms, green algae, and blue-green algae. The larvae construct fixed retreats and feed as collecting filterers.

A Checklist of the Caddisflies (Insecta: Trichoptera) from the Middle and Lower Basins of Jinsha River, Southwestern China; Including One New Species and Nine New Records in China

A checklist of trichopteran species in the middle and lower basins of the Jinsha River (southwestern China) is compiled for the first time. upon collected materials. It recorded ten families, 13 genera, and 23 species were recorded. Among them, the male of a new species Cheumatopsyche latisecta Ge & Sun, sp. nov., which can be diagnosed by its genitalia, is described and illustrated. In addition, nine other species are recorded for the first time from China, six species and three ones are recorded for the first time for Yunnan and Sichuan provinces, respectively. This trichopteran species list can provide guidance for caddisfly identification of the river and the region.

The InBIO barcoding initiative database: DNA barcodes of Iberian Trichoptera, documenting biodiversity for freshwater biomonitoring in a Mediterranean hotspot

Background

The Trichoptera are an important component of freshwater ecosystems. In the Iberian Peninsula, 380 taxa of caddisflies are known, with nearly 1/3 of the total species being endemic in the region. A reference collection of morphologically identified Trichoptera specimens, representing 142 Iberian taxa, was constructed. The InBIO Barcoding Initiative (IBI) Trichoptera 01 dataset contains records of 438 sequenced specimens. The species of this dataset correspond to about 37% of Iberian Trichoptera species diversity. Specimens were collected between 1975 and 2018 and are deposited in the IBI collection at the CIBIO (Research Center in Biodiversity and Genetic Resources, Portugal) or in the collection Marcos A. González at the University of Santiago de Compostela (Spain).

New information

Twenty-nine species, from nine different families, were new additions to the Barcode of Life Data System (BOLD). A success identification rate of over 80% was achieved when comparing morphological identifications and DNA barcodes for the species analysed. This encouraging step advances incorporation of informed Environmental DNA tools in biomonitoring schemes, given the shortcomings of morphological identifications of larvae and adult Caddisflies in such studies. DNA barcoding was not successful in identifying species in six Trichoptera genera: Hydropsyche (Hydropsychidae), Athripsodes (Leptoceridae), Wormaldia (Philopotamidae), Polycentropus (Polycentropodidae) Rhyacophila (Rhyacophilidae) and Sericostoma (Sericostomatidae). The high levels of intraspecific genetic variability found, combined with a lack of a barcode gap and a challenging morphological identification, rendered these species as needing additional studies to resolve their taxonomy.

Diversity and Composition of Caddisflies (Insecta: Trichoptera) along an Elevation Gradient in Southeastern Mexico

We analyzed the alpha and beta components of male Trichoptera diversity along an altitudinal gradient ranging from 136 to 2432 m a.s.l. by studying five assemblages of adult male caddisflies in five streams of the Sierra de Juárez, Oaxaca, Mexico. Samples were collected with light traps in the “nortes” (February) and rainy (October) seasons of 2016, recording air temperature and relative humidity. The assemblages showed an abundance pattern clearly associated with the rainy season, and a high dissimilarity in their species composition. Species richness and abundance were significantly higher at lower altitudinal levels. The highest alpha diversity was recorded in the Flor de Azahar stream; beta diversity increased with altitude and made an important contribution to gamma diversity. These results suggest that temporal and altitudinal variations affect environmental variables, which influence the structure of Trichoptera assemblages. Temperature was the primary factor determining spatial and temporal distribution patterns of caddisfly assemblages in the study area. However, in the rainy season, this factor explained a smaller proportion of the observed changes. Therefore, it is necessary to evaluate other environmental variables and explore other ecosystems to provide additional evidence on the factors affecting the diversity patterns of the Trichoptera in the Sierra de Juárez.

Immature stages of the limnephilid caddisfly Verger lutzi (Navás 1918) (Trichoptera: Limnephilidae): description and larval life-history traits in seasonal forested wetlands of Northwestern Patagonia

The genus Verger Navás 1918 (Trichoptera: Limnephilidae), is a Neotropical genus exclusive to the Andean region, with most of its species distributed from Tierra del Fuego to north central Chile and Argentina. Currently, 20 species of the genus have been described from adults and only six larvae have been associated and diagnosed. The ecology of the species is completely unknown. In this work, we describe and illustrate the immature stages of Verger lutzi (Navás 1918) and study its breeding phenology, larval growth and adult emergence. The main characters that enable the separation of this species are the coloration the body, shape of the anterior ventral apotome, shape and distribution of metanotal setal areas, distribution of tracheal gills and number of accessory teeth in the anal prolegs. Reproduction occurs during the summer and females lay their eggs on the wetland basin formed by humid leaf litter and organic debris, covered by herbaceous vegetation. Larvae hatch after flooding and overwinter in the wetland. Larvae develop fast during spring and emergence begins in December before the wetland dries up. Description of the immature stages is helpful for use of macroinvertebrates biomonitoring, ecological studies and understanding their ecosystem services in seasonal-lentic habitats.

The impact of sequencing depth and relatedness of the reference genome in population genomic studies: A case study with two caddisfly species (Trichoptera, Rhyacophilidae, Himalopsyche)

Whole genome sequencing for generating SNP data is increasingly used in population genetic studies. However, obtaining genomes for massive numbers of samples is still not within the budgets of many researchers. It is thus imperative to select an appropriate reference genome and sequencing depth to ensure the accuracy of the results for a specific research question, while balancing cost and feasibility. To evaluate the effect of the choice of the reference genome and sequencing depth on downstream analyses, we used five confamilial reference genomes of variable relatedness and three levels of sequencing depth (3.5×, 7.5× and 12×) in a population genomic study on two caddisfly species: Himalopsyche digitata and H. tibetana. Using these 30 datasets (five reference genomes × three depths × two target species), we estimated population genetic indices (inbreeding coefficient, nucleotide diversity, pairwise F ST, and genome-wide distribution of F ST) based on variants and population structure (PCA and admixture) based on genotype likelihood estimates. The results showed that both distantly related reference genomes and lower sequencing depth lead to degradation of resolution. In addition, choosing a more closely related reference genome may significantly remedy the defects caused by low depth. Therefore, we conclude that population genetic studies would benefit from closely related reference genomes, especially as the costs of obtaining a high-quality reference genome continue to decrease. However, to determine a cost-efficient strategy for a specific population genomic study, a trade-off between reference genome relatedness and sequencing depth can be considered.

Caddisfly Larvae are a Driver of Plastic Litter Breakdown and Microplastic Formation in Freshwater Environments

Plastic litter is now pervasive in the aquatic environment. Several marine and terrestrial organisms can fragment plastic with their feeding appendages, facilitating its breakdown and generating microplastics. However, similar studies with freshwater organisms are extremely limited. We explored the interactions between the caddisfly larvae Agrypnia sp. and polylactic acid (PLA) film. The use of plastic by larvae to build their protective cases was investigated, along with their ability to fragment the plastic film as they do with leaf litter. Caddisfly consistently incorporated PLA into their cases alongside leaf material. They also used their feeding appendages to rapidly fragment PLA-forming hundreds of submillimeter-sized microplastics. Although larvae showed a preference for leaf material when constructing cases, plastic use and fragmentation still occurred when leaf material was replete, indicating that this behavior is likely to occur in natural environments that are polluted with plastics. This is thought to be the first documented evidence of active plastic modification by a freshwater invertebrate and therefore reveals a previously unidentified mechanism of plastic fragmentation and microplastic formation in freshwater. Further work is now needed to determine the extent of this behavior across freshwater taxa and the potential implications for the wider ecosystem. Environ Toxicol Chem 2022;41:3058-3069. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Caddisfly (Trichoptera, Insecta) fauna and assemblages of the north-eastern part of the Pannonian Lowland (West Ukraine, Transcarpathia)

The caddisfly fauna of the Transcarpathian part of the Pannonian Lowland was poorly studied formerly. Here, we present the results of a six-year survey (2015-2020) carried out in four sampling sites of the Ukrainian part of the Bereg Plain and provide the actualised checklist of this area. Actually, 7346 specimens of 53 caddisfly species were collected. The number of known caddisfly species increased from 13 to 61. Two species Hydropsycheguttata and Parasetodesrespersellus, which formerly were considered extinct in the Pannonian Ecoregion, were detected and another especially rare species (e.g. Cyrnusflavidus) was also recorded. The fauna of the region cover a significant part of both Hungarian and Ukrainian caddisfly fauna. Assemblages of four characteristic habitat types of the region showed significant differences considering their quantitative and qualitative composition, substrate, current, hydrological- and feeding types. The high diversity and natural value of the small lowland watercourses were proven using a new Caddisfly Conservation Index (CCI) calculated, based on vulnerability and rarity of species. The fauna and assemblages showed a unique character mainly independent from large rivers of the region.

Case design and flow resistance in high-alpine caddisfly larvae (Insecta, Trichoptera)

For evaluating hydraulic stress reduction strategies of caddisfly larvae, our study has three goals. First, creating a database on Reynolds numbers (Re) and drag coefficients valid for Limnephilidae larvae with cylindrical mineral cases. Second, evaluating the effects of submerged weight and biometry in cases with comparable length/width ratios. And third, collecting field data in an alpine environment for gaining insights into the hydraulic niches occupied by thirteen Drusinae species. Biometric data were subsequently combined with published Reynolds numbers and mean flow velocity data measured immediately upstream of Limnephilidae larvae at the moment of dislodgement. This provides drag coefficients for the range of Reynolds numbers obtained in the field. Data reveal that heavy cases strongly benefit from compensating drag by submerged weight, thereby enabling species to utilize high velocity spots, an important benefit for filtering species.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10750-022-04981-y.

The caddisflies from Serra dos Órgãos National Park, Rio de Janeiro, Brazil, with the description of two new species of Ochrotrichia Mosely (Trichoptera: Hydroptilidae: Ochrotrichiinae)

The Serra dos Órgãos National Park (PARNASO) is a federal conservation unit located in Rio de Janeiro State, within the Atlantic Forest biome. This biome is one of the world’s biodiversity hotspots and has high diversity and endemism of caddisfly taxa. Here, we present a checklist of caddisflies from PARNASO, including the description of two new species of Ochrotrichia Mosely (Hydroptilidae). Ochrotrichia sino sp. nov. and Ochrotrichia papel sp. nov. are assigned to the O. aldama Species Group due to the divided tergum X in male genitalia, although in the first one tergum X is not simple as in most species in this group. Ochrotrichia sino sp. nov. is recognized by tergum X having a broad basal portion bearing a basodorsal spine-like process on the left side and the apical portion with two elongate processes, one curved and crossing the other one underneath. Ochrotrichia papel sp. nov. is distinguished by the elongate inferior appendages, by tergum IX having its posterior margin obliquely emarginate, and tergum X being divided into two processes, the left one longer and almost straight, the right one curved to the left, slightly upturned in lateral view. The list of PARNASO species is based on isolated records in literature and on specimens in the Coleção Entomológica Professor José Alfredo Pinheiro Dutra, Universidade Federal do Rio de Janeiro (Departamento de Zoologia) [UFRJ (DZRJ)], with samples collected since 2009. A total of 95 species were recorded from the PARNASO, of which eight are new distributional records for Rio de Janeiro State. Hydroptilidae (27 spp.), followed by Hydropsychidae (13 spp.), Leptoceridae, and Philopotamidae (12 spp. each) are the families with highest species richness. Before this work, only about 20 species of caddisflies were formally registered from the park area. In this way, this work is an important contribution to fill the gaps of knowledge caused by “Wallacean” and “Linnean” shortfalls.  

Notalina (Neonotalina) ralphi sp. nov. (Trichoptera, Leptoceridae), a new long-horned caddisfly from the Cerrado biome of Brazil, with new records for N. (Neonotalina) brasiliana Holzenthal, 1986 and an identification key

The long-horned caddisfly genus Notalina Mosely, 1936 contains 27 species divided into two subgenera. The Neotropical N. (Neonotalina) Holzenthal, 1986 occurs exclusively in South America. Its species are organized into two species groups, brasiliana and roraima. Nine species have been recorded so far in Brazil, mainly distributed in the Cerrado and Atlantic Forest biomes of Southeast Region, and only one species has been recorded from the Central-West and Northeast Regions. In this paper a new species of N. (Neonotalina) is described and illustrated based on adult males from two protected and preserved areas in the Cerrado biome of Brazil. Notalina (Neonotalina) ralphisp. nov. belongs to the brasiliana species group and can be recognized mainly by the morphology of the preanal appendages and segment X. New distributional records are provided for N. (Neonotalina) brasiliana Holzenthal, 1986. Additionally, a key to identify males of the ten species in the brasiliana species group is provided.

Caddisflies (Trichoptera) checklist and a new species of Helicopsyche von Siebold, 1856, from the Brejo de Altitude de Triunfo, a relict rainforest within the Caatinga domain, Northeast Brazil

Brejos de Altitude are evergreen seasonal forests, associated with plateau regions in the middle of the Caatinga domain in Northeast Brazil, which possibly acted as biological corridors between the Atlantic Forest and the Amazon rainforest during the Pleistocene. The first entomological survey in the highest point in the state of Pernambuco, Brazil, the Brejo de Altitude de Triunfo, was implemented and resulted in a checklist of caddisflies with six families, nine genera, and eleven species, including a new species. Helicopsycheralphi sp. nov. is described and illustrated, based on all semaphoronts. A key to Brazilian Helicopsyche (Feropsyche) Johanson, 1998 species is also provided. In addition to the caddisfly survey in the Brejos de Altitude, the results include new records for the state, region, and also for the country. Thus, this study updates the number of species in the Brazilian Northeast region and Pernambuco state to 169 species and 43 species, respectively.

Larval and female descriptions of Mejicanotrichia Harris & Holzenthal, 1997 (Trichoptera, Hydroptilidae, Leucotrichiinae) from Mexico

Mejicanotrichia Harris & Holzenthal, 1997 is a small genus of Hydroptilidae (Trichoptera), which consists of seven species, six of them distributed in Mexico, and one more in Guatemala. Larval descriptions of only two species (M.blantoni and M.estaquillosa) were previously known, as well as only females of three species (M.blantoni, M.estaquillosa, and M.tamaza) previously described. The present study provides descriptions of the larvae of M.harrisi and M.tridentata, as well as a description of the female of M.harrisi. Identification keys for adult males, known females, and known larvae are also provided. This work aims to incorporate more information into the taxonomy of the genus, its ecology, and facilitate additional characters of potential use in future phylogenetic studies.

Comparison of caddisfly (Insecta, Trichoptera) assemblages from lake and river habitats of the Huron Mountains of Michigan (USA)

The caddisfly assemblages of six lakes and 12 1^st-4^th order streams of the Huron Mountains of northern Upper Michigan (USA) were sampled monthly with ultraviolet lights during June-September 2019. A total of 169 species representing 63 genera and 19 families was collected, including five species not found elsewhere in Michigan and two species endemic to the state. Species assemblages between lotic and lentic habitats were distinct from each other, with 11 species indicating lakes and 23 indicating rivers. Despite the taxonomic differences, biomass of functional feeding groups (FFGs) was similar between lakes and rivers, except for higher biomass of predators in the former and higher biomass of filtering collectors in the latter. The FFG biomass of both habitat types was dominated (50-70%) by shredders. Considering the undisturbed condition of the habitats, the caddisfly assemblages and FFG biomass of the Huron Mountains can serve as regional biological monitoring reference conditions.

Three new species of Byrsopteryx Flint microcaddisflies from Peru (Insecta: Trichoptera) including DNA-based larval associations

In this paper, we have described and illustrated three new species of Byrsopteryx from Peru: Byrsopteryx inti, sp. nov.Byrsopteryx mamaocllosp. nov., and Byrsopteryx mancocapacsp. nov. Larvae of the latter two were also associated to male specimens based on comparison of a fragment of COI gene and pharate male identification. Byrsopteryx intisp. nov. and Byrsopteryx mamaocllosp. nov. share a unique feature: a semi-dome process formed by a thickened area on male forewings. The three species can be easily identified by wing coloration and male genitalia. Furthermore, Byrsopteryx intisp. nov. can be recognized by its sternum VIII with a median digitate process on posterior margin, slightly capitate; and by long dorsolateral processes from segment VIII, which cross each other apically in dorsal view. Byrsopteryx mamaocllosp. nov. can be distinguished by sternum VIII bearing a pair of short, posterior, spinelike processes, which are curved inwards and bordered by a rounded, membranous structure, and by a pair of short, heavily sclerotized, dorsolateral processes. Byrsopteryx mancocapacsp. nov. can be distinguished by strong spine-like processes arising dorsally from subgenital plate and by sternum VIII with posterior margin divided into two plate-like lobes. Larvae of B. mamaocllosp. nov. and B. mancocapacsp. nov. are similar to other Byrsopteryx larvae known. They can be distinguished from each other by the shape of the operculum formed by terga VIII and IX, and number of setae on the second abdominal pleurite. Maximum likelihood analyses of 20 COI sequences, including nine Byrsopteryx species, placed B. intisp. nov. and B. mamaocllosp. nov. as sister species and related to a clade including B. gomezi, B. tapanti, and B. esparta, while B. mancocapacsp. nov. was found as sister to B. abrelata. Despite the close phylogenetic relationship found between B. intisp. nov. and B. mamaocllosp. nov., they are separated by 14.9% minimum K2P divergence of COI. The highest intraspecific distance observed was 1.4% for B. mancocapacsp. nov. individuals. Although the Peruvian caddisfly fauna has around 320 known species and almost a third of them are microcaddisflies, in this paper we present the first descriptions of Byrsopteryx species for the country.

Patterns of invertebrate functional diversity highlight the vulnerability of ecosystem services over a 45-year period

Declines in invertebrate biodiversity^1,2 pose a significant threat to key ecosystem services.^3-5 Current analyses of biodiversity often focus on taxonomic diversity (e.g., species richness),^6,7 which does not account for the functional role of a species. Functional diversity of species' morphological or behavioral traits is likely more relevant to ecosystem service delivery than taxonomic diversity, as functional diversity has been found to be a key driver of a number of ecosystem services including decomposition and pollination.^8-12 At present, we lack a good understanding of long-term and large-scale changes in functional diversity, which limits our capacity to determine the vulnerability of key ecosystem services with ongoing biodiversity change. Here we derive trends in functional diversity and taxonomic diversity over a 45-year period across Great Britain for species supporting freshwater aquatic functions, pollination, natural pest control, and agricultural pests (a disservice). Species supporting aquatic functions showed a synchronous collapse and recovery in functional and taxonomic diversity. In contrast, pollinators showed an increase in taxonomic diversity, but a decline and recovery in functional diversity. Pest control agents and pests showed greater stability in functional diversity over the assessment period. We also found that functional diversity could appear stable or show patterns of recovery, despite ongoing changes in the composition of traits among species. Our results suggest that invertebrate assemblages can show considerable variability in their functional structure over time at a national scale, which provides an important step in determining the long-term vulnerability of key ecosystem services with ongoing biodiversity change.

Indirect Effect of Pesticides on Insects and Other Arthropods

Pesticides released to the environment can indirectly affect target and non-target species in ways that are often contrary to their intended use. Such indirect effects are mediated through direct impacts on other species or the physical environment and depend on ecological mechanisms and species interactions. Typical mechanisms are the release of herbivores from predation and release from competition among species with similar niches. Application of insecticides to agriculture often results in subsequent pest outbreaks due to the elimination of natural enemies. The loss of floristic diversity and food resources that result from herbicide applications can reduce populations of pollinators and natural enemies of crop pests. In aquatic ecosystems, insecticides and fungicides often induce algae blooms as the chemicals reduce grazing by zooplankton and benthic herbivores. Increases in periphyton biomass typically result in the replacement of arthropods with more tolerant species such as snails, worms and tadpoles. Fungicides and systemic insecticides also reduce nutrient recycling by impairing the ability of detritivorous arthropods. Residues of herbicides can reduce the biomass of macrophytes in ponds and wetlands, indirectly affecting the protection and breeding of predatory insects in that environment. The direct impacts of pesticides in the environment are therefore either amplified or compensated by their indirect effects.

Dynamic microhabitat shifts in space and time of caddisfly larvae (Insecta: Trichoptera) in a first‐order calcareous mountain stream

By studying substrate (choriotope) preferences of 25 caddisfly taxa in the Schreierbach stream, a calcareous, first order tributary of the Ybbs river (Lower Austria), we aimed on (1) detecting microhabitat preferences in space and time, (2) to relate this information with ontogenetic choriotope shifts, and (3) to explore relationships between feeding guilds and choriotopes chosen. For this, we took six sets of bi-monthly multi-habitat samples of larvae at three stream sections (360 samples). Densities were highest in Drusinae juveniles (53.60 %), Micrasema morosum (15.14 %), Drusus discolor (13.31 %) and D. monticola (4.46 %), and were significantly higher in the upper stream section (1900 ± 1039 larvae m− 2) than in the central (205 ± 23) and lower (141 ± 22). Ivlev electivity indices revealed preferences for Macrolithal in Rhyacophila spp. and Tinodes dives, for Microlithal in Drusinae juveniles, for Megalithal and Phytal in filtering Drusinae and Micrasema, and for Xylal and Akal in Limnephilinae. A cluster analysis of choriotope electivity yielded five clusters, corresponding with functional feeding types. At the instar level, the chosen grain size increased with increasing instar in some species. Observed habitat shifts in space and time reflected the interaction of instar-specific choriotope choice and longitudinal translocations.

Biochemically identified neuropeptides in a caddisfly (Trichoptera) and a pygmy mole cricket (Orthoptera: Caelifera: Tridactyloidea)

One representative of the order Trichoptera, namely the caddisfly Chaetopteryx villosa, was investigated along with the pygmy mole cricket Xya capensis which is a representative of the most basal superfamily of the caeliferan Orthoptera, that is, the Tridactyloidea. From both clades neuropeptides have not been biochemically characterized before this study. Here, members of the adipokinetic hormone family (AKHs) are sequenced via liquid chromatography (LC)-ion trap mass spectrometry from methanolic extracts from the corpora cardiaca of respective species. The corpora cardiaca were dissected, methanolic extracts prepared, peptides separated by liquid chromatography (LC), and AKHs detected and sequenced by ion trap mass spectrometry. Both species investigated contain an octapeptide AKH: the trichopteran species has the peptide with the sequence pGlu-Leu-Thr-Phe-Thr-Pro-Ser-Trp amide; the ambiguity of the isobaric amino acids Leu and Ile at position two was solved by comparing retention times on LC and by co-elution with the synthetic Leu² -form. This peptide is known as Aedae-AKH and found in certain dipteran species and in an alderfly (Megaloptera). The tridactyloid species contains the peptide with the sequence pGlu-Val-Asn-Phe-Ser-Pro-Gly-Trp amide which had first been identified in a member of the order Mantophasmatodea and is called Manto-CC. Comparisons are made between the AKH complements of the sister groups Trichoptera and Lepidoptera and their possible relatedness and, on the other hand, between the AKH of X. capensis with those of closely related caeliferan superfamilies. The biology of the two studied species is used to speculate about a possible function of the elucidated hormones. Lastly, the use of a larval stage as starting material for structural neuropeptide information is discussed.

Peeling the Layers of Caddisfly Diversity on a Longitudinal Gradient in Karst Freshwater Habitats Reveals Community Dynamics and Stability

Simple Summary

Freshwater biodiversity is facing a severe crisis due to many different human-caused impacts, such as climate change, pollution, habitat alterations, etc. Aquatic insects are one of the most important bioindicators used in freshwater ecological quality assessment systems, yet knowledge on diversity dynamics of their communities is incomplete. In the current study, we compare and evaluate performance of different diversity measures, i.e., commonly used simple diversity indices vs. novel complex measures incorporating ecological information of species (feeding behavior and stream zonation preferences). As a target group, we chose caddisflies, a species-rich, aquatic insect order, in different habitats of an anthropogenically unimpacted, connected karst barrage lake/riverine system. In line with our hypothesis, the complex diversity measures were more efficient in ranking and distinguishing different habitats, particularly the ones with similar communities. We also constructed a novel measure to rank the habitats by sensitivity to climate change, based on diversity of caddisfly communities and vulnerability of species inhabiting them. As expected, the springs were ranked as most vulnerable habitats. Our study further underlines the importance of integrating ecological information into biodiversity and vulnerability assessment of freshwater communities.

Abstract

Freshwater biodiversity is facing a severe crisis due to many human impacts, yet the diversity dynamics of freshwater communities and possibilities of assessing these are vastly unexplored. We aimed at emphasizing different aspects of portraying diversity of a species-rich, aquatic insect group (caddisflies; Trichoptera) across four different habitats in an anthropogenically unimpacted, connected karst barrage lake/riverine system. To define diversity, we used common indices with pre-set sensitivity to species abundance/dominance; i.e., sensitivity parameter (species richness, Shannon, Simpson, Berger-Parker) and diversity profiles based on continuous gradients of this sensitivity parameter: the naïve and non-naïve diversity profiles developed by Leinster and Cobbold. The non-naïve diversity profiles show diversity profiles with regard to the similarity among species in terms of ecological traits and preferences, whereas the naïve diversity profile is called mathematically “naïve” as it assumes absolute dissimilarity between species that is almost never true. The commonly used indices and the naïve diversity profile both ranked the springs as least diverse and tufa barriers as most diverse. The non-naïve diversity profiles based on similarity matrices (using feeding behavior and stream zonation preferences of species), showed even greater differences between these habitats, while ranking stream habitats close together, regardless of their longitudinal position. We constructed the Climate Score index (CSI) in order to assess how diversity and species’ vulnerability project the community’s resistance and/or resilience to climate change. The CSI ranked the springs as most vulnerable, followed by all habitats longitudinally placed below them. We highlight the importance of integrating ecological information into biodiversity and vulnerability assessment of freshwater communities.

Draft Genome Assemblies and Annotations of Agrypnia vestita Walker, and Hesperophylax magnus Banks Reveal Substantial Repetitive Element Expansion in Tube Case-Making Caddisflies (Insecta: Trichoptera)

Trichoptera (caddisflies) play an essential role in freshwater ecosystems; for instance, larvae process organic material from the water and are food for a variety of predators. Knowledge on the genomic diversity of caddisflies can facilitate comparative and phylogenetic studies thereby allowing scientists to better understand the evolutionary history of caddisflies. Although Trichoptera are the most diverse aquatic insect order, they remain poorly represented in terms of genomic resources. To date, all long-read based genomes have been sequenced from individuals in the retreat-making suborder, Annulipalpia, leaving ∼275 Ma of evolution without high-quality genomic resources. Here, we report the first long-read based de novo genome assemblies of two tube case-making Trichoptera from the suborder Integripalpia, Agrypnia vestita Walker and Hesperophylax magnus Banks. We find that these tube case-making caddisflies have genome sizes that are at least 3-fold larger than those of currently sequenced annulipalpian genomes and that this pattern is at least partly driven by major expansion of repetitive elements. In H. magnus, long interspersed nuclear elements alone exceed the entire genome size of some annulipalpian counterparts suggesting that caddisflies have high potential as a model for understanding genome size evolution in diverse insect lineages.

Tools for instar determination of European caddisfly larvae (Insecta: Trichoptera)

The paper explores the adult-forewing-length to larval-head-width relationship as a basis for instar determination of final instar caddisfly larvae on a family level. In addition, reference data from published sources were used to extract series of percentage-head-width increments and factors-of-increase for penultimate to first instars. This material provides estimates for head widths of earlier instars on the family level.

Small Patches of Riparian Woody Vegetation Enhance Biodiversity of Invertebrates

Patches of riparian woody vegetation potentially help mitigate environmental impacts of agriculture and safeguard biodiversity. We investigated the effects of riparian forest on invertebrate diversity in coupled stream-riparian networks using a case study in the Zwalm river basin (Flanders, Belgium). Agriculture is one of the main pressures in the basin and riparian forest is limited to a number of isolated patches. Our 32 study sites comprised nine unshaded “unbuffered” sites which were paired with nine shaded “buffered” sites on the same stream reach, along with five ‘least-disturbed’ sites and nine downstream sites. We sampled water chemistry, habitat characteristics and stream and riparian invertebrates (carabid beetles and spiders) at each site. Three methods were used to quantify riparian attributes at different spatial scales: a visually-assessed qualitative index, quantitative estimates of habitat categories in six rectangular plots (10 × 5 m) and geographic information system (GIS)-derived land cover data. We investigated relationships between invertebrates and riparian attributes at different scales with linear regression and redundancy analyses. Spiders and carabids were most associated with local riparian attributes. In contrast, aquatic macroinvertebrates were strongly influenced by the extent of riparian vegetation in a riparian band upstream (100–300 m). These findings demonstrate the value of quantifying GIS-based metrics of riparian cover over larger spatial scales into assessments of the efficacy of riparian management as a complement to more detailed local scale riparian assessments in situ. Our findings highlight the value of even small patches of riparian vegetation in an otherwise extensively disturbed landscape in supporting biodiversity of both terrestrial and freshwater invertebrates and emphasize the need to consider multiple spatial scales in riparian management strategies which aim to mitigate human impacts on biodiversity in stream-riparian networks.

Taxonomic Catalog of the Brazilian Fauna: order Trichoptera (Insecta), diversity and distribution

Caddisflies are a highly diverse group of aquatic insects, particularly in the Neotropical region where there is a high number of endemic taxa. Based on taxonomic contributions published until August 2019, a total of 796 caddisfly species have been recorded from Brazil. Taxonomic data about Brazilian caddisflies are currently open access at the “Catálogo Taxonômico da Fauna do Brasil” website (CTFB), an on-line database with taxonomic information on the animal species occurring in Brazil. The order Trichoptera at CTFB includes a catalog of species recorded for the country, with synonymic lists, distribution throughout six biomes, 12 hydrographic regions, and 27 political states (including Federal District) from Brazil. The database is constantly updated to include newly published data. In this study, we reviewed the taxonomic effort on Brazilian caddisflies based on data currently in CTFB database. The accumulation curve of species described or recorded from the country, by year, shows a strong upward trend in last 25 years, indicating that it is possible that there are many more species to be described. Based on presence/absence of caddisfly species at three geographic levels (biomes, hydrographic regions, and states), second order Jackknife estimated at least 1,586 species occurring in Brazil (with hydrographic regions as unities), indicating we currently know about 50% of the Brazilian caddisfly fauna. Species distribution by Brazilian biomes reveals that the Atlantic Forest is the most diverse, with 490 species (298 endemic), followed by the Amazon Forest, with 255 species (101 endemic). Even though these numbers may be biased because there has been more intense collecting in these two biomes, the percentage of endemic caddisfly species in the Atlantic Forest is remarkable. Considering the distribution throughout hydrographic regions, clustering analyses (UPGMA) based on incidence data reveals two groups: northwestern basins and southeastern. Although these groups have weak bootstrap support and low similarity in species composition, this division of Brazilian caddisfly fauna could be related to Amazon-Atlantic Forest disjunction, with the South American dry diagonal acting as a potential barrier throughout evolutionary time.

A novel leaf-rolling chironomid, Eukiefferiella endobryonia sp. nov. (Diptera, Chironomidae, Orthocladiinae), highlights the diversity of underwater chironomid tube structures

The non-biting midges, Chironomidae (Diptera), are dominant components of most freshwater ecosystems. Many chironomids construct tubes or cases as larvae out of various materials bound together with silk. The structures of tubes show a wide range of variation, and some are morphologically comparable to those of caddisflies. Herein a new species is described, Eukiefferiella endobryonia sp. nov., which exhibits a very unusual behavior in which it constructs tubes from aquatic mosses. This species' fourth-instar larvae construct their cases exclusively from the leaves of Fontinalis mosses (Hypnales: Fontinalaceae) and exhibit a stereotyped behavior in which they remain attached to the apical shoot of the moss stem. The larvae then pupate within the case. The case of E. endobryonia sp. nov. represents one of only a few examples of chironomid tubes made exclusively out of plants. Based on the species delimitation analyses using the partial COI sequences, together with some morphological and behavioral characteristics, this species is hypothesized to be a member of devonica group, and especially may have a close affinity to E. dittmari (Lehman). A provisional typology for the diversity of chironomid tube structures is provided, with a summary of different tube structures, which can be used for future research.

Annotated Draft Genomes of Two Caddisfly Species Plectrocnemia conspersa CURTIS and Hydropsyche tenuis NAVAS (Insecta: Trichoptera)

Members of the speciose insect order Trichoptera (caddisflies) provide important ecosystem services, for example, nutrient cycling through breaking down of organic matter. They are also of industrial interest due to their larval silk secretions. These form the basis for their diverse case-making behavior that allows them to exploit a wide range of ecological niches. Only five genomes of this order have been published thus far, with variable qualities regarding contiguity and completeness. A low-cost sequencing strategy, that is, using a single Oxford Nanopore flow cell per individual along with Illumina sequence reads was successfully used to generate high-quality genomes of two Trichoptera species, Plectrocnemia conspersa and Hydropsyche tenuis. Of the de novo assembly methods compared, assembly of low coverage Nanopore reads (∼18×) and subsequent polishing with long reads followed by Illumina short reads (∼80-170× coverage) yielded the highest genome quality both in terms of contiguity and BUSCO completeness. The presented genomes are the shortest to date and extend our knowledge of genome size across caddisfly families. The genomic region that encodes for light (L)-chain fibroin, a protein component of larval caddisfly silk was identified and compared with existing L-fibroin gene clusters. The new genomic resources presented in this paper are among the highest quality Trichoptera genomes and will increase the knowledge of this important insect order by serving as the basis for phylogenomic and comparative genomic studies.