Search Results (33)

Laboratory and field investigations were used to assess the toxicity of leachate from a closed sanitary landfill on benthic macroinvertebrates in coldwater trout streams located near a landfill in southeastern Minnesota, USA. Field-collected invertebrates were exposed to a range of concentrations (0–100%) of leachate during a series of 24 h and 7-day laboratory toxicity tests. Benthic macroinvertebrates also were collected from two stream sites on either side of the landfill and at a third site downstream to assess potential pollution exposure of the stream communities. Ten different taxa exposed to 100% leachate for 24 h exhibited survival ranging from 0 to 100%, with survivorship not correlated to published invertebrate pollution tolerance values. More extensive 24 h tests with the least tolerant Brachycentrus caddisfly larvae found 100% mortality at leachate concentrations > 70%, with the first mortalities observed after 3 h. Brachycentrus had 100% survival at leachate concentrations < 40%. During 7-day tests, Brachycentrus had 100% survival at all leachate concentrations of 40% and lower, but all Brachycentrus died after 2 days at concentrations of 60% and higher. Instream benthic communities, averaging 12 to 17 different taxa at the various stream sites, were rated from good to excellent based on biotic index values, with intolerant taxa present at all three stream sites. Landfill leachate has not impacted the benthic invertebrate communities in streams nearby, but leachate at higher concentrations has the potential to be toxic to a variety of local taxa. Full article

With increasing contamination in aquatic ecosystems, effective monitoring is crucial to preserve biodiversity and protect public health. This study quantified bioindicators (red swamp crayfish (Pcla), Genji-firefly (Lcr2), Ayu fish (Paa), and caddisfly (Sma)), microbial source tracking markers (ruminants (BacR), pigs (Pig2Bac), and humans (gyrB)), and a fecal indicator bacterium (Escherichia coli (sfmD)) using quantitative PCR on river water samples collected every 2 h between 21 and 22 July 2023 (from the Omo and Bingushi Rivers in Yamanashi Prefecture, Japan). Initially, the optimal filter sizes of 1.0, 0.65, and 0.22 µm were evaluated, where the 0.65 µm filter yielded higher Paa concentrations (Kruskal–Wallis test, p < 0.05) and was used subsequently. BacR and Paa exhibited 100% detection in the Omo (13/13) and Bingushi (13/13) Rivers with concentrations of 5.0 log₁₀ and 5.5 log₁₀ copies/L, respectively. These concentrations were used to assess 24 h temporal variability, but no significant fluctuations or cyclical trends between morning, afternoon, evening, and night were observed in either river. The BacR–Paa pair exhibited perfect positive detection correlation (Φ = 1.0) and complete similarity (Jaccard Index = 1.0), but a moderate negative correlation of mean concentrations highlights the importance of considering habitat overlaps and behavioral synchronicity. Full article

The use of focal plane array micro-Fourier transform infrared spectroscopy (FPA-μFTIR) enables high-resolution characterization of microplastics (MPs) in a wide variety of matrices, including both biotic and abiotic samples. However, this technique has not yet been applied to study MP ingestion in organisms in areas with low MP pollution (e.g., national parks or protected areas). In this study, FPA-μFTIR was used to quantify MPs in the bodies of aquatic insects collected from a high-altitude stream (~2000 m) in Taiwan. Results showed that MP ingestion occurred in nearly all examined taxa, except for caddisfly (Trichoptera: Stenopsychidae) and dragonfly (Odonata: Gomphidae). The majority of MPs were smaller than 500 μm, and the dominant MP polymers identified were polyethylene (65%) and polypropylene (30%), which occurred mainly as fragments (83%) and, to a lesser extent, as fibers (17%). The highest number of MP particles was in the scraper functional-feeding group (FFG), while MPs were not detectable in collector–filterer FFG. The highest MP concentration (particles/individuals) was found in the waterpenny beetle Ectopria sp., followed by the mayflies Paraleptophlebia sp. and Epeorus erratus, and Chironomidae in the subfamily Tanypodinae. We suggest that using high-resolution FPA-μFTIR can be effectively applied to study and monitor MP ingestion in remote, pristine ecosystems. Full article

Caenocentron was previously hypothesized to have originated in Mesoamerica from Xiphocentronidae ancestors that dispersed from Asia to the Americas during Eocene hyperthermal events. Under this scenario, the genus underwent early diversification in Mesoamerica and reached South America only during the late Miocene, following the uplift and connection of Central America. However, the discovery of Caenocentron roosevelt sp. nov. in savanna areas of the Brazilian Amazon significantly revises this understanding. A morphology-based parsimony analysis of Caenocentron and related xiphocentronids (26 taxa, 46 characters) recovered C. roosevelt sp. nov. as the sister species to all other members of the genus. This placement implies that Caenocentron was in South America far earlier than previously inferred, likely by the late Oligocene. Caenocentron roosevelt sp. nov. is distinguished by the following combination of characters: the absence of a setose ventral projection on the coxopodite (present in all other congeners), the presence of apical lobes on tergum IX (reduced in other species), paired digitate lobes beneath the posterior margin of tergum IX (otherwise found only in one Nearctic species), and a distinct line of robust setae along the apical projection of the coxopodite (absent in other species). Additionally, a key to the males of all 10 currently recognized species of Caenocentron is provided. Full article

This study aimed to assess the presence of microplastics (MPs) in an urban river (Gari, Lazio, Italy) using case-building caddisfly larvae as potential bioindicators. Results from the benthic faunal assemblage (STAR_ICMi = 0.797) revealed the presence of a rich and well-diversified macroinvertebrate community, thus reflecting a suitable ecological status. Of 279 caddisfly cases collected, 26% contained small plastic particles of various shapes and colours, while 542 MP items per m² were found in their substrate. Polyvinyl chloride (PVC) and Polyethylene terephthalate (PET) were the most abundant polymers identified by FT-IR analysis found in the Gari River, while the co-presence of lower-density polymers such as polystyrene (PS) and polyethylene (PE) or polypropylene (PP) reflects the contribution of multiple factors controlling MP deposition. The most abundant MPs were of secondary origin, as evidenced by the Carbonyl Index and the predominant shape. Despite the amounts of MPs found in the Gari River, their ecological and chemical status has been classified as “good” during the monitoring campaigns. These results highlight the need to further investigate the environmental impacts of MPs to implement water quality classification indices. Full article

Despite being the subgenus with the highest number of species within Chimarra Stephens, 1829 in Brazil, information about Chimarra (Curgia) Walker, 1980 is scarce in the Brazilian semi-arid region. Beyond the discussion about the quantity of species reported for this region, there is also a temporal gap concerning original descriptions of this subgenus in Brazil. Thus, 15 years after the last description of C. (Curgia) in Brazil, we diagnosed, described, and illustrated two new species based on adult males collected in the Caatinga and Cerrado biomes in the state of Piauí, viz., Chimarra (Curgia) opala sp. nov. and Chimarra (Curgia) prata sp. nov. They can be recognized mainly by the morphology of tergum X, preanal appendage, and phallotheca spines. Moreover, they do not conform to the characteristics of any species group traditionally known in the genus. While sharing similarities with the species compared in this study, these comparisons are limited to isolated characters and do not encompass all the features representing the groups of their respective species. Full article

The long-horned caddisfly Brachysetodes Schmid, 1955 (Leptoceridae: Leptocerinae) is a small genus endemic to the Andean region, especially Chile. Four decades after the last taxonomic revision, a new species, Brachysetodes tricahue Desidério, Santana & Hamada sp. nov., is described and illustrated based on adult males collected from Parque Natural Tricahue in the central subregion of the Chilean Andes. Specimens were examined through genital dissection using heated KOH, photographed with a digital camera mounted on microscopes, and described using the DELTA system. A distribution map was produced in QGIS based on GBIF data and literature records, and an updated identification key for males of the ten known species of Brachysetodes sensu stricto is presented. B. tricahue sp. nov. closely resembles B. bifurcatus and B. nublensis, sharing key features such as paired lateral processes on tergum X and tripartite inferior appendages. However, it can be distinguished by its unique combination of genital features, including unequal lengths of the three processes of the inferior appendage. This discovery emphasizes the underexplored diversity of the Southern Andes and contributes to refining the taxonomy and biogeography of the genus. It also provides a framework for future phylogenetic studies incorporating immature stages and molecular data. Full article

The unique properties of insect silk have attracted attention for years to develop scaffolds for tissue engineering. Combining natural silks with synthetic polymers may benefit biocompatibility, mechanical strength, and elasticity. Silk-modified biomaterials are a promising choice for tissue engineering due to their versatility, biocompatibility, and many processing methods. This study investigated the physicochemical and biological properties of biocomposites formed by combining caddisfly silk (Hydropsyche angustipennis) and polycaprolactone (PCL). The PCL foams modified with caddisfly silk demonstrated full cytocompatibility and enhanced fibroblast adhesion and proliferation compared to unmodified PCL. These silk-modified PCL foams also induced NF-κB signaling, which is crucial for initiating tissue regeneration. Notably, the antimicrobial properties of the silk-modified PCL foams remained consistent with those of unmodified PCL, suggesting that the addition of silk did not alter this aspect of performance. The findings suggest that caddisfly silk-modified PCL foams present a promising solution for future medical and dental applications, emphasizing the potential of alternative silk sources in tissue engineering. Full article

The geographic ranges of slimy (Uranidea cognata) and mottled (Uranidea bairdii) sculpin overlap broadly across cool and coldwater streams and rivers in North America, where they can serve very important roles in fish community dynamics. The diet diversities of slimy and mottled sculpin were examined in early March (late winter) during eight out of nine years after the August 2007 catastrophic flooding in four streams to assess potential diet shifts as benthic invertebrate prey communities recovered post-flood. In total, 10,823 prey items, representing 39 invertebrate taxa and three fish taxa were identified from the stomachs of 532 slimy sculpins (present in Garvin Brook, Gilmore Creek, and Trout Run) and 179 mottled sculpins (present in Middle Fork Whitewater River). Only four prey taxa were consumed by sculpin in all streams: midge larvae and pupae (Diptera: Chironomidae), blackfly larvae and pupae (Diptera: Simuliidae), Hydropsyche caddisfly larvae (Trichoptera: Hydropsychidae), and Baetis mayfly nymphs (Ephemeroptera: Baetidae). Midges dominated diets of both slimy (61% of prey by number) and mottled (76%) sculpin across all years. Consequently, Shannon diversities of diets were typically low across all years and streams for slimy sculpin (annual site range 0.07–0.83) and across years for mottled sculpin (annual range 0.11–0.46). Diversities and taxa richness of slimy sculpin diets increased in Garvin Brook and Trout Run across the study years (driven by significant declines in midge dominance) but remained relatively unchanged for slimy sculpin in Gilmore Creek and mottled sculpin in the Middle Fork. Individual slimy and mottled sculpin differed significantly both in the numbers of taxa consumed per fish (<2 versus 2.5 taxa/fish, respectively) and in the numbers of individual prey per fish (11 versus 26 prey, respectively). Slimy sculpin in two streams displayed modest shifts in diets as benthic prey communities recovered during the 9-year period post-flood, whereas slimy and mottled sculpin in other streams displayed little to no changes in diets. Differing flood severity among streams may have produced the different responses observed in sculpin diets. Full article

The genus Cernotina Ross, 1938 is represented in the southeastern United States by three nominal species: Cernotina calcea Ross, 1938, Cernotina spicata Ross, 1938, and Cernotina truncona Ross, 1947. Of all Cernotina species, only the larva of C. spicata has been described to date. The goal of this paper is to describe, illustrate, and diagnose the larva of C. truncona using ecologically associated specimens. In addition, we used publicly available mitochondrial DNA barcoding data to evaluate the genetic relationships of these species. The larvae of Cernotina truncona can be distinguished from those of C. spicata by differences in setal placement and number on the meso- and metanota, mandibular morphology, head width, and distal setation of the tarsi. The ultrastructure of the anal claw is figured, highlighting the novel finding of small spines on the concave margin of a larva of Cernotina. With this new description, just the second described larva from this genus, only C. calcea remains unknown in the southeastern United States. The information provided herein enables the in-depth study of the ecology and life history of this diminutive caddisfly. Full article

Suspended and deposited sediments in streams can interfere with filter-feeding caddisfly larvae by reducing feeding sites and feeding efficiency, potentially lowering the densities, growth rates, and secondary production of an important trout prey. We conducted field studies at multiple stream sites with differing suspended-sediment loads, and a laboratory study was conducted under controlled conditions; together, these were designed to examine the role of suspended sediments in the population dynamics and behavior of Brachycentrus occidentalis (Trichoptera: Brachycentridae) larvae in a Minnesota, USA, trout stream. Stream sites that had elevated turbidities and elevated levels of suspended sediments also had significantly more fine bottom substrates and higher substrate embeddedness. In addition, Brachycentrus densities were reduced, growth rates were slower, secondary production was reduced, and the overall benthic macroinvertebrate taxa richness was lowest at the site with the highest suspended-sediment loading. Colder water temperatures at one site also influenced Brachycentrus production. In 24 h laboratory studies conducted in recirculating aquaria, the feeding activities of Brachycentrus larvae were reduced and their positioning altered under high turbidities (500 nephelometric turbidity units, NTU) relative to low turbidities (50 NTU or lower). High suspended-sediment loads have adversely affected filter-feeding caddisfly larvae by embedding and burying preferred coarse feeding substrates, altering their feeding positions and movements during the highest flows, and potentially impacting densities, growth rates, and secondary production. Full article

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. Full article

Climate change is considered one of the greatest threats to freshwater biodiversity. Although freshwater biodiversity is an important contributor to economic, scientific, and cultural aspects of human society, freshwater species, especially invertebrates, tend to be neglected in conservation studies. This fact also raises the question of the suitability of protected areas (PAs) for the conservation of freshwater biodiversity. In our study, we used species distribution models (SDMs) to examine the effects of climate change on the two trichopteran species Helicopsyche bacescui Orghidan and Botosaneanu, 1953 and Thremma anomalum McLachlan, 1876. We determined which areas in the Balkans and neighboring countries might be lost to or colonized by these species in the future, and tested the effectiveness of PAs for the conservation of freshwater biota. While H. bacescui will potentially lose up to 68% of its range, T. anomalum could expand its range by up to 72%. Both species tend to shift their range mainly to the Carpathian Mountains. Our results suggest that currently established PAs are insufficient to cover the potential current and predicted future ranges of the studied species. The study therefore highlights the need to combine aquatic and terrestrial systems in the future designation of protected areas. Full article

Marilia is the most diverse genus of the caddisfly family Odontoceridae, being distributed throughout the Oriental, Australasian and Neotropical regions. Herein, we describe four new Neotropical species from the Atlantic Forest, Rio Doce basin, Brazil. This basin was partly affected by a flood of 50 million m³ of mud and mining debris in 2015. Due to this disaster, numerous monitoring activities have been carried out to assess the impact generated. Material from one of these attempts was used to describe the new species: Marilia aranan sp. nov., Marilia krenak sp. nov., M. maxakali sp. nov. and M. mukurin sp. nov. Additionally, we provide a new state record of M. guaira from Minas Gerais. Marilia aranan sp. nov. was collected in tributaries as well as in the impacted area 7 years after the disaster. Marilia guaira and M. krenak sp. nov. were collected only in the impacted area. The other species were found only in tributaries. Odontoceridae are considered highly sensitive to disturbance. The presence of Marilia species suggests that parts of the riverbed have recovered from the fine tailing sediments and also highlights the importance of tributaries in the recolonization process. Full article

Four new species of the genus Eoneureclipsis Kimmins, 1955 from China are described, illustrated, and diagnosed based on male genitalia: Eoneureclipsis jianfenglingensis sp. nov. from Hainan, E. foraminulatus sp. nov. from Guangxi, E. spinosus sp. nov. from Guangxi and Guangdong, and E. gei sp. nov. from Fujian. A dichotomous key to Chinese adult males of Eoneureclipsis is provided. A distribution map for all Eoneureclipsis species is also presented. The DNA barcodes (partial mtCOI sequences) of E. jianfenglingensis sp. nov., E. gei sp. nov., and E. hainanensis Mey, 2013 have been generated and compared with all existing sequences of Eoneureclipsis species. Full article