Chironomidae Research Articles

AMI-KMNP dataset: Occurrence records of aquatic macroinvertebrate species from a 10-year-long biodiversity survey in SE Hungary

We outline a 100% georeferenced dataset of aquatic macroinvertebrate occurrence records collected from the operational area of the Körös-Maros National Park Directorate (SE Hungary) between 2012 and 2021. The species-level dataset includes 25,935 records of 644 taxa from 625 localities of wide variety of freshwater habitats from soda pans to lowland marshes and small watercourses to medium-sized and larger rivers. Four non-biting midge species are reported for the first time from the Hungarian fauna. The dataset is available through the Global Biodiversity Information Facility (GBIF).

A temporal perspective on aquatic subsidy: Bti affects emergence of Chironomidae

Emerging aquatic insects serve as one link between aquatic and adjacent riparian food webs via the flux of energy and nutrients. These insects provide high-quality subsidy to terrestrial predators. Thus, any disturbance of emergence processes may cascade to higher trophic levels and lead to effects across ecosystem boundaries. One stressor with potential impact on non-target aquatic insects, especially on non-biting midges (Diptera: Chironomidae), is the widely used mosquito control agent Bacillus thuringiensis var. israelensis (Bti). In a field experiment, we investigated emerging insect communities from Bti-treated (three applications, maximum field rate) and control floodplain pond mesocosms (FPMs) over 3.5 months for changes in their composition, diversity as well as the emergence dynamics and the individual weight of emerged aquatic insects over time. Bti treatments altered community compositions over the entire study duration – an effect mainly attributed to an earlier (∼10 days) and reduced (∼26%) peak in the emergence of Chironomidae, the dominant family (88% of collected individuals). The most reasonable explanation for this significant alteration is less resource competition caused by a decrease in chironomid larval density due to lethal effects of Bti. This is supported by the higher individual weight of Chironomidae emerging from treated FPMs (∼21%) during Bti application (April – May). A temporal shift in the emergence dynamics can cause changes in the availability of prey in linked terrestrial ecosystems. Consequently, terrestrial predators may be affected by a lack of appropriate prey leading to bottom-up and top-down effects in terrestrial food webs. This study indicates the importance of a responsible and elaborated use of Bti and additionally, highlights the need to include a temporal perspective in evaluations of stressors in aquatic-terrestrial meta-ecosystems.

Composition and Dynamics of Hexapod Communities on Yushan Bamboo (Yushania niitakayamensis) in the Subtropical Montane Areas of Taiwan.

Plant communities that colonize high-elevation zones generally have short growing seasons which lead to specialized adaptations in such zones. In montane areas of Taiwan, Yushan bamboo (YB, Yushania niitakayamensis) is dominant at elevations ranging from 2500 to 3300 m and grows in a grassland-like open habitat. In this study, hexapods were collected from YB bimonthly between 2009 and 2012 by using a sweeping net. The composition of and several bioindices for the hexapods were determined, and multivariate analyses were conducted to explore the dynamics and seasonal distribution of the hexapods. A total of 32,000 individuals belonging to 11 orders and 113 families were collected, with adult individuals being collected more frequently in warmer seasons (from June to October). Of the sampled individuals, 90% belonged to the orders Collembola (42%), Hemiptera (35%), and Hymenoptera (13%). The number of individuals belonging to Hemiptera were stable in all seasons, and the number of hymenopteran wasps was influenced by temperature and exhibited a stable dynamic pattern. The number of individuals belonging to Collembola fluctuated dramatically. The multivariate analyses revealed that the collected hexapods could be divided into two major family groups according to survey season (i.e., summer and winter groups). Several families were collected only in summer, but a few were collected only in winter. Eigenvalues obtained from a principal component analysis revealed that the families Chironomidae, Delphacidae, Entomobryidae, Hypogastruridae, Sminthuridae, and Thripidae (all dominant) were the major contributors to the winter group. These families were abundant all year, although some were more abundant during winter. The three dominant orders Collembola, Hemiptera, and Hymenoptera, each of which has a distinct community structure and dynamic pattern, may have their own adaptive mechanisms in the subtropical regions of Taiwan. Hemiptera individuals, which feed on YB, were most abundant in the adult stage in summer and in the nymphal stage in winter. The abundance of parasitic hymenopteran wasps, which had stable dynamic patterns, was associated with that of their host insects and temperature. The drastic fluctuations in the abundance of Collembola may have been caused by abiotic factors, such as precipitation and microhabitat factors. The early onset of spring and the late onset of winter might also affect the dynamics of the studied hexapods.

Aquatic-Terrestrial Insecticide Fluxes: Midges as Neonicotinoid Vectors.

Exposure of freshwater ecosystems to insecticides can negatively impact the development of emerging aquatic insects. These insects serve as an important nutritional subsidy for terrestrial insectivores. Changes in insect emergence phenology (i.e., emergence success and temporal pattern) or fluxes of insecticides retained by the emerging adults have the potential to negatively impact terrestrial food webs. These processes are influenced by contaminant toxicity, lipohilicity, or metabolic processes. The interplay between emergence phenology, contaminant retention through metamorphosis, and associated contaminant flux is not yet understood for current-use insecticides. In a microcosm study, we evaluated the impacts of a 24-h pulse exposure of one of three current-use insecticides, namely pirimicarb, indoxacarb, and thiacloprid, at two environmentally realistic concentration levels on the larval development and emergence of the nonbiting midge Chironomus riparius. In addition, we measured insecticide concentrations in the larvae and adults using ultrahigh performance liquid chromatography coupled to tandem mass spectrometry by electrospray ionization. Exposure to pirimicarb delayed larval development and emergence, and exposure to indoxacarb reduced emergence success. The neonicotinoid thiacloprid had the greatest impact by reducing larval survival and emergence success. At the same time, thiacloprid was the only insecticide measured in the adults with average concentrations of 10.3 and 37.3 ng/g after exposure at 0.1 and 4 µg/L, respectively. In addition, an approximate 30% higher survival to emergence after exposure to 0.1 µg/L relative to a 4-µg/L exposure resulted in a relatively higher flux of thiacloprid, from the aquatic to the terrestrial environment, at the lower exposure. Our experimental results help to explain the impacts of current-use insecticides on aquatic-terrestrial subsidy coupling and indicate the potential for widespread dietary exposure of terrestrial insectivores preying on emerging aquatic insects to the neonicotinoid thiacloprid. Environ Toxicol Chem 2023;42:60-70. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Contributions to the Faunistic Knowledge of Chironomidae (Diptera) of Turkey Based on the Adult Males Collected Around Hazar Lake (Elazığ)

In the present study, adult male specimens from the non-biting midge family (Chironomidae) collected around the Hazar Lake (Elazığ, Türkiye) in 2021 were evaluated taxonomically. We collected a total of 17 species in three subfamilies of Tanypodinae, Orthocladiinae, and Chironominae. Two species Cryptotendipes pseudotener (Goetghebuer, 1922), and Dicrotendipes pallidicornis (Goetghebuer, 1934) are new faunistic records for Türkiye. 11 species were observed for the first time in the Hazar Lake, although they have been reported previously in Türkiye. These include: Procladius (Holotanypus) choreus (Meigen, 1804), Cricotopus (Cricotopus) bicinctus (Meigen, 1818), Cricotopus (Cricotopus) festivellus (Kieffer, 1906), Cryptotendipes pseudotener (Goetghebuer, 1922), Cryptochironomus (Cryptochironomus) rostratus Kieffer, 1921, Dicrotendipes pallidicornis (Goetghebuer, 1934), Polypedilum sp., Polypedilum (Tripodura) bicrenatum Kieffer, 1921, Polypedilum (Pentapedilum) sordens (van der Wulp, 1875), Micropsectra radialis Goetghebuer, 1939, and Tanytarsus sp.

Tube length of chironomid larvae as an indicator for dissolved oxygen in water bodies

Tube-building larvae of non-biting midges, or chironomids, are considered bioindicators of water pollution. The larvae use benthic particles to make their tubes and create a respiratory current with the movement of their bodies inside the tubes. The tube length of the chironomid larvae varies depending on several physicochemical properties of the aquatic medium. Here we study the role of physicochemical parameters on the tube length from different field sites and in the laboratory. It appears that among different physicochemical factors, dissolved oxygen (DO) has a major role in determining the tube length of the larvae. A quantitative relationship between oxygen concentration and the tube length of larvae is presented here. Our study reveals a longer tube in aquatic media with oxygen deficiency and a shorter tube in those with higher oxygen. This result may help to assess the quality of water bodies and, in particular the status of DO.

Assessment of pollution variability across the central part of the Büyük Menderes River (Turkey) using water physicochemical parameters and biomarker responses in the non-biting midge Chironomus riparius (Diptera: Chironomidae)

ABSTRACT This study aimed to examine the pollution level in the central part of the Büyük Menderes River (in both the main tributary and Çürüksu stream) in Denizli (Turkey) using water physicochemical parameters and biomarker responses in Chironomus riparius (Diptera: Chironomidae). In physicochemical parameter evaluations, Sığma, Korucuk, and Güzelköy stations were determined to have higher mean temperature, pH, salinity, conductivity, and total dissolved solids (TDS) values and lower dissolved oxygen (dO2) and saturated oxygen (sO2) values than Bekilli, Mahmutlu, and Sarayköy stations. In biomarker response evaluations, C. riparius larvae from Sarayköy, Sığma, Korucuk, and Güzelköy stations were found to exhibit inhibited acetylcholinesterase (AChE) activities (55%−68%) and elevated 7-ethoxyresorufin O-deethylase (EROD) activities (191%−281%), glutathione S-transferase (GST) activities (138%−187%), and metallothionein (MT) contents (155%−231%) when compared with the control values. This study proves that different stations are exposed to different pollution sources, the pollution level of a station varies depending on the season, and the stations on Çürüksu stream, among which Güzelköy appears to be the most contaminated, are exposed to more pollutants than those on the main tributary of the river.

Selective effects of a short transient environmental fluctuation on a natural population.

Natural populations experience continuous and often transient changes of environmental conditions. These in turn may result in fluctuating selection pressures leading to variable demographic and evolutionary population responses. Rapid adaptation as short-term response to a sudden environmental change has in several cases been attributed to polygenic traits, but the underlying genomic dynamics and architecture are poorly understood. In this study, we took advantage of a natural experiment in an insect population of the non-biting midge Chironomus riparius by monitoring genome-wide allele frequencies before and after a cold snap event. Whole genome pooled sequencing of time series samples revealed 10 selected haplotypes carrying ancient polymorphisms, partially with signatures of balancing selection. By constantly cold exposing genetically variable individuals in the laboratory, we could demonstrate with whole genome resequencing (i) that among the survivors, the same alleles rose in frequency as in the wild, and (ii) that the identified variants additively predicted fitness (survival time) of its bearers. Finally, by simultaneously sequencing the genome and the transcriptome of cold exposed individuals we could tentatively link some of the selected SNPs to the cis- and trans-regulation of genes and pathways known to be involved in cold response of insects, such as cytochrome P450 and fatty acid metabolism. Altogether, our results shed light on the strength and speed of selection in natural populations and the genomic architecture of its underlying polygenic trait. Population genomic time series data thus appear as promising tool for measuring the selective tracking of fluctuating selection in natural populations.

Genome-wide annotation of cuticular protein genes in non-biting midge Propsilocerus akamusi and transcriptome analysis of their response to heavy metal pollution

The insect cuticle is a sophisticated chitin-protein extracellular structure for mutable functions. The cuticles varied their structures and properties in different species, and the same species but in different regions or at different stages, to fill the requirements of different functions. The alteration of cuticle structures may also be induced due to challenges by some environmental crises, such as pollution exposures. The physical properties of the cuticle were determined by the cuticle proteins (CPs) they contain. The cuticle proteins are large protein groups in all insects, which are commonly divided into different families according to their conserved protein sequence motifs. Although Chironomidae is an abundant and universal insect in global aquatic ecosystems and a popular model for aquatic toxicology, no systematic annotation of CPs was done for any species in Chironomidae before. In this work, we annotated the CP genes of Propsilocerus akamusi, the most abundant Chironomidae species in Asia. A total of 160 CP genes were identified, and 97 of them could be well classified into eight CP families: 76 CPR genes can be subdivided into three groups (further divided into three subgroups: 36 RR1 genes, 37 RR2 genes, and 3 RR3 genes), 2 CPF genes, 3 CPLCA genes, 1 CPLCG gene, 8 CPAP genes, and 3 Tweedle genes. Additionally, we analyzed the response of P. akamusi CP genes at expression level to Cu exposure, which is related to the high heavy metal tolerance and the earlier onset of pupariation in heavy metal polluted water.

Ecological impacts of N-deposition in a remote, high-elevation lake in the Three River Headwaters Region, Qinghai-Tibetan Plateau

This study provides a new record of nitrogen (N) deposition and ecological response at a remote, high-elevation lake within the ecologically fragile Three River Headwaters Region, northwest China, from the early 20thCentury to the past decade. A multi-proxy investigation of a lake sediment core including analyses of chironomids (non-biting midge), lake sediment geochemistry (δ15N, δ13C, TN, TOC, OC:TN), pollen, non-pollen palynomorphs and 210Pb-dating. Results were compared with regional pollution forcings, including fertiliser application, atmospheric nitrate and dust deposition, and a localised multiscale air quality modelling system for N-deposition. Our data reflect a mesotrophic lake for the majority of the 20th Century with minimal anthropogenic impact. A shift in the lake conditions is evident after 1985 with increased nutrient enrichment. Low δ15N, OC:TN and increasing TN values, together with an increase in chironomid taxa associated with eutrophic conditions and macrophytes are exhibited in the record, particularly since 2002. These changes are consistent with nutrient loading causing a change in trophic status. Redundancy analysis (RDA) and partial RDAs verified TN as an important driver behind the shift in chironomid community composition in recent decades, explaining 22.2% of the variance on its own and 16.9% with other environmental variables partialled out. While temperature change since 1960 was not a primary control on the chironomid community of Lake Bander, a step-change increase in summer temperatures since the 1990s coincided with the disappearance of cold stenotherms from the record and seems to have exacerbated the shift to more productive conditions. This study highlights the reach of airborne N from modern agricultural and industrial activity to remote locations, and demonstrates the utility of palaeolimnological techniques as part of modern ecosystem assessment for conservation.

Genome-Wide Identification of P450 Genes in Chironomid Propsilocerus akamusi Reveals Candidate Genes Involved in Gut Microbiota-Mediated Detoxification of Chlorpyrifos.

Simple SummaryPropsilocerus akamusi is considered as a pollution-tolerant chironomid species in aquatic ecosystems. The capability of adapting to various contamination has been proved to rely on certain detoxifying enzymes, such as cytochrome P450 (P450), glutathione S-transferase (GST), etc. In the present study, 64 P450 genes were derived and characterized based on the available genome sequence. In addition, there is a potential role of gut microbial commensals in regulating local P450s when individuals have to deal with environmental stressors. Two screened P450s of gut tissue, PaCYP3998B1 and PaCYP3987D1, were remarkably decreased in chlorpyrifos-challenged subjects with deficient gut microbiota; this result suggested a possible function of gut microbial communities in enhancing host endogenous detoxification capability.Chironomids commonly dominate macroinvertebrate assemblages in aquatic habitats and these non-biting midges are known for their ability to tolerate contaminants. Studies regarding the interplay between gut microbiota and host detoxification ability is currently a point of interest. Cytochrome P450s (P450s) are critical metabolic enzymes in which a subset is involved in xenobiotic detoxification. In this study, we first conducted an integrated global investigation of P450s based on the whole genomic sequence of Propsilocerus akamusi and retrieved a series of 64 P450 genes which were further classified into 4 clans and 25 families on the basis of phylogenetic relationships. With assistance of RNA-Seq and RT-qPCR validation, the expression profile of screened PaP450s in guts was compared between chlorpyrifos-challenged larvae with deficient gut microbiota (GD) and those with a conventional gut community (CV). An increasing prevalence of chlorpyrifos from sublethal to lethal dosages induced a greater mortality rate of individuals coupled with remarkable downregulation of 14 P450s in GD larval guts when compared to CV ones. Moreover, it turned out that the decreased level of PaCYP3998B1 and PaCYP3987D1 might imply impaired host endogenous detoxification capability potentiated by gut dysbiosis, reflected by a remarkably severe mortality in GD larvae treated with lethal chlorpyrifos. Collectively, our study unveiled candidate P450 genes that might be mediated by gut symbionts in chlorpyrifos-challenged P. akamusi larvae, possibly facilitating further understanding of the detoxified mechanism that chironomids might employ to alleviate poisonousness.

A Quick Review of the Family Chironomidae (Order Diptera) with Effect on the Environment

Context: The Chironomidae family is more sensitive to changes in water environment quality. This taxon is tolerant in stream ecosystems. Thus, it could be used as a bio-indicator of freshwater to recognize the presence of contaminants with deleterious effects on human health. Evidence Acquisition: We searched keywords Chironomidae, bioindicator, environment, water stream, water quality, anthropogenic disturbance, pollutant, fossil, industrial waste, and aquatic habitats. Chironomidae was used once in single and again in combination with others. Google Scholar, Scopus, Springer, ScienceDirect, PubMed, ProQuest, JSTOR, EBSCO, BioOne, ResearchGate, Sage, Wiley Online Library, and SID were used as databases or search engines. Then, the results were sorted into four sections: Distribution and ecology, biotic indicators, food, and paleoecological studies. Results: The identification key of chironomids should be improved based on morphological and molecular data to determine this family more clearly. Identifying sub-fossil chironomid insects found in the sediments of lakes unravels the range of environments during the history of its aquatic habitat through paleoecological investigations. Conclusions: Chironomidae at genera or species has variations in traits in the ecosystems. Each species as a bio-indicator has different tolerable condition in its own habitat .Overall, the role of this family in all types of pollutants is ambiguous. More studies are needed to particularize the importance of Chironomidae based on genera and species.

Current information about zoobenthos and assessment of the ecological state of the Boguchany reservoir

The regulation of river flow entails a change in the habitat of aquatic organisms. Biological communities can vary and be formed over several years, that is why it is necessary to monitor the state of reservoir ecosystems regularly. Currently, there is a significant gap in modern studies of the benthic fauna of the Boguchany reservoir, which is the lower stage of the Angarsk hydro-electric power station cascade. During five years (2014–2015, 2017–2019), zoobenthos communities had been studied in the lower part of the Boguchany reservoir. The benthic fauna was chironomid-gammarid in nature with a predominance of chironomids. 75 species of invertebrates were identified, 39 of them belong to dipterous insects of the Chironomidae family. The shallow water communities are qualitatively and quantitatively much richer than in the deep water zone. With a decrease in depth, there was an increase in the number of invertebrates by about 6 times due to the small-sized species of chironomids. The number of zoobenthos in the deep water zone was 0.3 thousand ind./m2, in the shallow water — 1.8 thousand ind./m2. The biomass in different deep zones did not differ significantly: in the deep part — 2.0 g/m2, in shallow water — 2.4 g/m2. The trophic status of the Boguchany reservoir in 2018 corresponded to the mesotrophic type of medium food capacity (III class), in other years — to the oligotrophic type of low food capacity (II class). Nowadays, the formation of bottom fauna is at the stage of biocenosis stabilization. An integrated approach of three bioindicative indicators (Mayer, saprobity and Shannon indices) was used to assess water quality according to bottom communities. The fundamental criterion for the selection of indices was the consideration of the benthocenosis structural organization, i.e. the development degree of indicator taxa.Water quality, assessed by the state of zoobenthos communities, corresponded to III class, “Moderately polluted”, β-mesosaprobic zone

New data on non-biting midges of the subfamily Chironominae (Diptera, Chironomidae) of the Buryatia Republic and the adjacent territories, Russia

New data on non-biting midges of the subfamily Chironominae (Diptera, Chironomidae) of the Buryatia Republic and the adjacent territories, Russia

Contribution of sediment contamination to multi-stress in lowland waters

Water bodies in densely populated lowland areas are often impacted by multiple stressors. At these multi-stressed sites, it remains challenging to quantify the contribution of contaminated sediments. This study, therefore, aimed to elucidate the contribution of sediment contamination in 16 multi-stressed drainage ditches throughout the Netherlands. To this end an adjusted TRIAD framework was applied, where 1) contaminants and other variables in the sediment and the overlying water were measured, 2) whole-sediment laboratory bioassays were performed using larvae of the non-biting midge Chironomus riparius, and 3) the in situ benthic macroinvertebrate community composition was determined. It was hypothesized that the benthic macroinvertebrate community composition would respond to all jointly present stressors in both water and sediment, whereas the whole-sediment bioassays would only respond to the stressors present in the sediment. The benthic macroinvertebrate community composition was indeed related to multiple stressors in both water and sediment. Taxa richness was positively correlated with the presence of PO4-P in the water, macrophyte cover and some pesticides. Evenness, the number of Trichoptera families and the SPEARpesticides were positively correlated to the C:P ratios in the sediment, whilst negative correlations were observed with various contaminants in both the water and sediment. The whole-sediment bioassays with C. riparius positively related to the nutrient content of the sediment, whereas no negative relations to the sediment-associated contaminants were observed, even though the lowered SPEARpesticides index indicated contaminant effects in the field. Therefore, it was concluded that sediment contamination was identified as one of the various stressors that potentially drove the benthic macroinvertebrate community composition in the multi-stressed drainage ditches, but that nutrients may have masked the adverse effects caused by low and diverse sediment contaminants on C. riparius in the bioassays.

Review of the Rheotanytarsus muscicola Species Group from China (Diptera: Chironomidae)

The Rheotanytarsus muscicola species group is generally considered to be a taxonomically difficult group of non-biting midges (Diptera: Chironomidae). In this study, we review the R. muscicola species group based on the adult males from China using morphology and DNA barcodes. Rheotanytarsus ferringtoni Lin & Yao sp. n. is described and figured, and four species (Rheotanytarsus falcipedius Kyerematen, Andersen & Sæther, 2000; Rheotanytarsus fluminis Kawai & Sasa, 1985; Rheotanytarsus illiesi Siebert, 1979; and Rheotanytarsus photophilus Goetghebuer, 1921) new to China are redescribed, figured and discussed. An updated key to known adult males of the R. muscicola species group is presented. Our study shows concordance between morphological species concepts and DNA barcodes.

Organic matter degradation and redistribution of sediment associated contaminants by benthic invertebrate activities

The fate of sediment associated compounds is the combined result of chemical properties and biological activities. Yet, studies simultaneously addressing the effects of biota on the redistribution and bioaccumulation of contaminants are scarce. Our aim was therefore to assess the effect of benthic invertebrate activities on organic matter degradation and the redistribution of metals and Polycyclic Aromatic Hydrocarbons (PAHs) in contaminated sediment. To this end, we introduced egg ropes of the non-biting midge Chironomus riparius into wastewater treatment plant sludge and allowed these to either develop until fourth instar larvae or to fully complete their life cycle into terrestrial flying adults. Chironomid larvae enhanced sludge degradation, resulting in increased metal concentrations in the sludge and in a flux of metals into the overlying water. Moreover, they hampered PAH degradation in the sludge. Contaminant transport from aquatic to terrestrial ecosystems with emerging invertebrates as a vector is widely acknowledged, but here we showed that biomanipulation prevailed over bioaccumulation, since due to chironomid activity, the flux of metals from the sludge into the overlying water was larger than into chironomid biomass. It is therefore concluded that contaminant-macroinvertebrate interactions are bilateral relationships driven by the interplay between macroinvertebrate traits and contaminant properties.

Mitogenomes provide new insights of evolutionary history of Boreheptagyiini and Diamesini (Diptera: Chironomidae: Diamesinae).

Mitogenomes have been widely used for phylogenetic reconstruction of various Dipteran groups, but specifically for chironomid, they have not been carried out to resolve the relationships. Diamesinae (Diptera: Chironomidae) are important bioindicators for freshwater ecosystem monitoring, but its evolutionary history remains uncertain for lack of information. Here, coupled with one previously published and 30 new mitogenomes of Diamesinae, we carried out comparative mitogenomic analysis and phylogenetic analysis. Mitogenomes of Diamesinae were conserved in structure, and all genes arranged in the same order as the ancestral insect mitogenome. All protein‐coding genes in Diamesinae were under stronger purifying selection than those of other nonbiting midge species, which may exhibit signs of adaptation to life at cold living conditions. Phylogenetic analyses strongly supported the monophyly of Diamesinae, with Boreheptagyiini deeply nested within Diamesini. In addition, phylogenetic relationship of selected six genera was resolved, except Sympotthastia remained unstable. Our study revealed that the mitogenomes of Diamesinae are highly conserved, and they are practically useful for phylogenetic inference.

Towards the systematics and diversity of Neotropical Tanytarsus van der Wulp (Diptera: Chironomidae): news from Colombia.

Our study pertains to the systematics and diversity of non-biting midges of the genus Tanytarsus van der Wulp, 1874 from the Neotropical region and in particular, Colombia, a country scarcely studied for these dipterans to date. Adult male specimens collected from the Colombian Llanos and Andes biomes belong to five species described as new in the present paper: Tanytarsus colombiensis sp. nov. (placed in the caipira species group, here defined), T. germani sp. nov. and T. gnomon sp. nov. (both placed in the curvicristatus group, here defined), T. lulu sp. nov. (in the ligulatus group, here defined) and T. meta sp. nov. (the riopreto group). Also an illustrated brief redescription of the adult male of T. hastatus Sublette et Sasa, 1994 is provided. After reclassification of Caladomyia Swedal, 1981, the name accepted as a junior synonym of Tanytarsus, several species names became homonyms, thus they are here proposed to be replaced with substitute names, as follows: Tanytarsus reiffi nom. nov. pro Tanytarsus reissi (Reiff, 2000); Tanytarsus sanseverinoi nom. nov. pro Tanytarsus angelae Trivinho-Strixino et Shimabukuro, 2017; Tanytarsus trivinhostrixinoi nom. nov. pro Tanytarsus fittkaui Sanseverino et Trivinho-Strixino, 2010. Rheotanytarsus breda (Roback, 1960) comb. nov. is excluded from Tanytarsus. An annotated checklist of Neotropical Tanytarsus, with 89 species, is also presented.

Emerging Midges Transport Pesticides from Aquatic to Terrestrial Ecosystems: Importance of Compound- and Organism-Specific Parameters.

Emerging aquatic insects have the potential to retain aquatic contaminants after metamorphosis, potentially transporting them into adjacent terrestrial food webs. It is unknown whether this transfer is also relevant for current-use pesticides. We exposed larvae of the nonbiting midge, Chironomus riparius, to a sublethal pulse of a mixture of nine moderately polar fungicides and herbicides (logKow 2.5-4.7) at three field relevant treatment levels (1.2-2.5, 17.5-35.0, or 50.0-100.0 μg/L). We then assessed the pesticide bioaccumulation and bioamplification over the full aquatic-terrestrial life cycle of both sexes including the egg laying of adult females. By applying sensitive LC-MS/MS analysis to small sample volumes (∼5 mg, dry weight), we detected all pesticides in larvae from all treatment levels (2.8-1019 ng/g), five of the pesticides in the adults from the lowest treatment level and eight in the higher treatment levels (1.5-3615 ng/g). Retention of the pesticides through metamorphosis was not predictable based solely on pesticide lipophilicity. Sex-specific differences in adult insect pesticide concentrations were significant for five of the pesticides, with greater concentrations in females for four of them. Over the duration of the adults' lifespan, pesticide concentrations generally decreased in females while persisting in males. Our results suggest that a low to moderate daily dietary exposure to these pesticides may be possible for tree swallow nestlings and insectivorous bats.