Artificial light at night bans Chaoborus from vital epilimnetic waters.

Artificial light at night (ALAN) is known to affect organisms in terrestrial ecosystems and adjacent litoral habitats. In the present study, we tested the effect of ALAN on the spatial distribution of organisms in open waters, using the insect larvae of Chaoborus flavicans as an example. During the day C. flavicans typically hide from visually hunting fish in deep, dark, anoxic waters. On safer nights, they forage in rich subsurface waters. Nighttime field tests revealed that light from an HPS street lamp mounted on a boat anchored in open water attracted planktivorous fish, but deterred planktonic Chaoborus from rich but risky surface waters. Chaoborus did not descend to the safest, anoxic hypolimnion, but remained in hypoxic mid-depth metalimnion, which does not appear to be a perfect refuge. Neither light gradient nor food distribution fully explained their mid-depth residence under ALAN conditions. A further laboratory test revealed a limited tolerance of C. flavicans to anoxia. Half of the test larvae died after 38 h at 9 °C in anoxic conditions. The trade-off between predation risk and oxygen demand may explain why Chaoborus did not hide in deep anoxic waters, but remained in the riskier metalimnion with residual oxygen under ALAN conditions.

Comparative mitogenome analyses of twelve non-biting flies and provide insights into the phylogeny of Chironomidae (Diptera: Culicomorpha).

The family Chironomidae is represented by seven subfamilies in China, among which Chironominae and Orthocladiinae are the most diverse. To gain a better understanding of the architecture and evolution of the mitogenomes of Chironomidae, we sequenced mitogenomes of twelve species (including two published species) of the two subfamilies Chironominae and Orthocladiinae, and comparative mitogenomic analyses were performed. Thus, we identified highly conserved genome organization of twelve species with regard to genome content, nucleotide and amino acid composition, codon usage, and gene characteristics. The Ka/Ks values of most protein-coding genes were far smaller than 1, indicating that these genes were evolving under purifying selection. Phylogenetic relationships between the family Chironomidae were reconstructed using 23 species representing six subfamilies, based on protein-coding genes and rRNAs using Bayesian Inference and Maximum Likelihood. Our results suggested the following relationship within the Chironomidae: (Podonominae + Tanypodinae) + (Diamesinae + (Prodiamesinae + (Orthocladiinae + Chironominae))). This study contributes to the mitogenomic database of Chironomidae, which will be significant for studing the mitogenome evolution of Chironomidae.

World Catalogue of the family Thaumaleidae (Diptera: Culicomorpha).

Family, genus and species group names in the family Thaumaleidae (Diptera: Culicomorpha) are catalogued, including information on name-bearing types, distribution by country and 428 references to all literature known to us pertaining to this family. The Thaumaleidae or madicolous midges are known from 202 species in the following seven genera: Afrothaumalea Stuckenberg, 1960 (3 species), Androprosopa Mik, 1898 (59 species), Austrothaumalea Tonnoir, 1927 (44 species), Neothaumalea Pivar, Moulton & Sinclair, 2018 (1 species), Niphta Theischinger, 1986 (14 species), Thaumalea Ruthe, 1831 (77 species) and Trichothaumalea Edwards, 1929 (4 species). In addition, one fossil genus and species are known (Mesothaumalea fossilis Kovalev). Published species distributions are provided, noting country and biogeographic region; specimen data representing new records for species are listed. The following new combinations, originally assigned to Thaumalea, are proposed: Androprosopa baminana (Yang, 2003) comb. nov., Androprosopa zhejiangana (Yang, 1998) comb. nov.

The immatures of three Neotropical species of Palpomyia Meigen (Diptera, Culicomorpha, Ceratopogonidae).

The first description of the fourth instar larva and pupa of Palpomyia mapuche Spinelli, Grogan & Ronderos and the pupa of P. subfuscula Ingram & Macfie are provided, as well as the redescription of the pupa of P. subaspera (Coquillett). Studied specimens were collected in lotic environments of Argentinian Patagonia, in Neuquén and Chubut Provinces. The described stages were examined and illustrated with a phase-contrast microscope. The larva was examined using a scanning electron microscope. Data on the bionomics for P. mapuche and new records for the three species are provided.

Elevated pCO2 affects behavioural patterns and mechano-sensation in predatory phantom midge larvae Chaoborus obscuripes.

Aquatic acidification is a major consequence of fossil fuel combustion. In marine ecosystems it was shown, that increasing pCO2 levels significantly affect behavioural and sensory capacities in a diversity of species. This can result in altered predator and prey interactions and thereby change community structures. Just recently also CO2 dependent acidification of freshwater habitats has been shown. Also here, increased levels of pCO2 change organisms' behaviour and sensory capacities. For example, the freshwater crustacean Daphnia's ability to detect predators and accurately develop morphological defences was significantly reduced, rendering Daphnia more susceptible to predation. It was speculated that this may have cascading effects on freshwater food webs. However, for a comprehensive understanding of how increased levels of CO2 affect trophic interactions, it is also important to study how CO2 affects predators. We tested this using the dipeteran phantom midge larva Chaoborus obscuripes, which is a world-wide abundant inhabitant of freshwater impoundments. We monitored activity parameters, predation parameters, and predation rate. Chaoborus larvae are affected by increased levels of pCO2 as we observed an increase in undirected movements and at the same time, reduced sensory abilities to detect prey items. This is likely to affect the larvae's energy budgets. Chaoborus is a central component of many freshwater food-webs. Therefore, CO2 effects on predator and prey levels will likely have consequences for community structures.

Cloning and characterization of Methoprene-tolerant (Met) and Krüppel homolog 1 (Kr-h1) genes in the wheat blossom midge, Sitodiplosis mosellana.

Juvenile hormone (JH), a growth regulator, inhibits ecdysteroid-induced metamorphosis and controls insect development and diapause. Methoprene-tolerant (Met) and Krüppel homolog 1 (Kr-h1) are two proteins involved in JH action. To gain some insight into their function in development of Sitodiplosis mosellana, an insect pest undergoing obligatory larval diapause at the mature 3rd instar stage, we cloned full-length complementary DNAs of Met and Kr-h1 from this species. SmMet encoded a putative protein, which contained three domains typical of the bHLH-PAS family and eight conserved amino acid residues important for JH binding. SmKr-h1 encoded a protein showing high sequence homology to its counterparts in other species, and contained all eight highly conserved Zn-finger motifs for DNA-binding. Expression patterns of SmMet and SmKr-h1 were developmentally regulated and JH III responsive as well. Their mRNA abundance increased as larvae entered early 3rd instar, pre-diapause and maintenance stages, and peaked during post-diapause quiescence, a pattern correlated with JH titers in this species. Different from reduced expression of SmMet, SmKr-h1 mRNA increased at mid-to-late period of post-diapause development. Topical application of JH III on diapausing larvae also induced the two genes in a dose-dependent manner. Expression of SmMet and SmKr-h1 clearly declined in the pre-pupal phase, and was significantly higher in female adults than male adults. These results suggest that JH-responsive SmMet and SmKr-h1 might play key roles in diapause induction and maintenance as well as in post-diapause quiescence and adult reproduction, whereas metamorphosis from larvae to pupae might be correlated with their reduced expression.

Modeling the global distribution of Culicoides imicola: an Ensemble approach.

Culicoides imicola is a midge species serving as vector for a number of viral diseases of livestock, including Bluetongue, and African Horse Sickness. C. imicola is also known to transmit Schmallenberg virus experimentally. Environmental and demographic factors may impose rapid changes on the global distribution of C. imicola and aid introduction into new areas. The aim of this study is to predict the global distribution of C. imicola using an ensemble modeling approach by combining climatic, livestock distribution and land cover covariates, together with a comprehensive global dataset of geo-positioned occurrence points for C. imicola. Thirty individual models were generated by 'biomod2', with 21 models scoring a true skill statistic (TSS) >0.8. These 21 models incorporated weighted runs from eight of ten algorithms and were used to create a final ensemble model. The ensemble model performed very well (TSS = 0.898 and ROC = 0.991) and indicated high environmental suitability for C. imicola in the tropics and subtropics. The habitat suitability for C. imicola spans from South Africa to southern Europe and from southern USA to southern China. The distribution of C. imicola is mainly constrained by climatic factors. In the ensemble model, mean annual minimum temperature had the highest overall contribution (42.9%), followed by mean annual maximum temperature (21.1%), solar radiation (13.6%), annual precipitation (11%), livestock distribution (6.2%), vapor pressure (3.4%), wind speed (0.8%), and land cover (0.1%). The present study provides the most up-to-date predictive maps of the potential distributions of C. imicola and should be of great value for decision making at global and regional scales.

Mitochondrial Genomes Provide Insights into the Phylogeny of Culicomorpha (Insecta: Diptera).

Culicomorpha is a monophyletic group containing most bloodsucking lower dipterans, including many important vectors of pathogens. However, the higher-level phylogenetic relationships within Culicomorpha are largely unresolved, with multiple competing hypotheses based on molecular sequence data. Here we sequenced four nearly complete mitochondrial (mt) genomes representing four culicomorph families, and combined these new data with published mt genomes to reconstruct the phylogenetic relationships of all eight extant culicomorph families. We estimated phylogenies using four datasets and three methods. We also used four-cluster likelihood mapping to study potential incongruent topologies supported by the different datasets and phylogenetic questions generated by the previous studies. The results showed that a clade containing Ceratopogonidae, Thaumaleidae and Simuliidae was the sister group to all other Culicomorpha; in another clade, the Dixidae was basal to the remaining four families; Chaoboridae, Corethrellidae and Culicidae formed a monophyletic group and the Chironomidae was the sister group to this clade; Culicidae and Corethrellidae were sister groups in all trees. Our study provides novel mt genome data in Culicomorpha for three new family representatives, and the resulting mt phylogenomic analysis helps to resolve the phylogeny and taxonomy of Culicomorpha.

Flexible foraging strategies in Pipistrellus pygmaeus in response to abundant but ephemeral prey.

There is growing recognition that with sympathetic management, plantation forests may contain more biodiversity than previously thought. However, the extent to which they may support bat populations is contentious. Many studies have demonstrated active avoidance of coniferous plantations and attributed this to the lack of available roost sites and low invertebrate density. In contrast, other work, carried out in plantation dominated landscapes have shown that certain bat species are able to exploit these areas. However, the extent to which bats use plantations for roosting and foraging, or simply move through the plantation matrix to access more favourable sites is unclear. We radio tracked female Pipistrellus pygmaeus over two summers to establish the extent to which individual bats use Sitka Spruce plantations in southern Scotland for foraging and roosting and assess the implications for felling operations on bats. Maternity roosts identified (n = 17) were in all in buildings and most were large (> 500 individuals). We found no evidence of bats roosting in mature Sitka Spruce crop trees, although several bats used roosts in old or dead beech and oak trees as an alternative to their main maternity roost. Home ranges were much larger (mean 9.6 ± 3.12 km2) than those reported from other studies (0.6-1.6 km2), and it is likely that roost availability rather than food abundance constrains P. pygmaeus use of Sitka Spruce plantations. At the landscape scale, most individuals selected coniferous habitats over other habitat types, covering large distances to access plantation areas, whilst at a local scale bats used forest tracks to access water, felled stands or patches of broadleaf cover within the plantation. Sitka Spruce plantations support a high abundance of Culicoides impuctatus, the Highland midge which may act as a reliable and plentiful food source for females during lactation, an energetically expensive period. The use of felled stands for foraging by bats has implications for forest management as wind turbines, following small-scale felling operations, are increasingly being installed in plantations; wind turbines have been associated with high bat mortality in some countries. Decisions about siting wind turbines in upland plantations should consider the likelihood of increased bat activity post felling.

Porewater methane transport within the gas vesicles of diurnally migrating Chaoborus spp.: An energetic advantage.

Diurnally-migrating Chaoborus spp. reach populations of up to 130,000 individuals m-2 in lakes up to 70 meters deep on all continents except Antarctica. Linked to eutrophication, migrating Chaoborus spp. dwell in the anoxic sediment during daytime and feed in the oxic surface layer at night. Our experiments show that by burrowing into the sediment, Chaoborus spp. utilize the high dissolved gas partial pressure of sediment methane to inflate their tracheal sacs. This mechanism provides a significant energetic advantage that allows the larvae to migrate via passive buoyancy rather than more energy-costly swimming. The Chaoborus spp. larvae, in addition to potentially releasing sediment methane bubbles twice a day by entering and leaving the sediment, also transport porewater methane within their gas vesicles into the water column, resulting in a flux of 0.01-2 mol m-2 yr-1 depending on population density and water depth. Chaoborus spp. emerging annually as flies also result in 0.1-6 mol m-2 yr-1 of carbon export from the system. Finding the tipping point in lake eutrophication enabling this methane-powered migration mechanism is crucial for ultimately reconstructing the geographical expansion of Chaoborus spp., and the corresponding shifts in the lake's biogeochemistry, carbon cycling and food web structure.

The complete mitochondrial genome of Dixella aestivalis (Diptera: Nematocera: Dixidae).

Dixidae, meniscus midges, belong to the suborder Nematocera of the order Diptera. The family includes 197 known species classified in nine genera. The complete mitochondrial genome of the Dixella aestivalis (Meigen) from the United Kingdom is reported here, along with its annotation and comparison with the genome of an unidentified species of Dixella from China. The circular genome consists of 16 465 bp and has a gene content consisting of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and a non-coding, A + T-rich, control region. The mitochondrial genome of D. aestivalis can be used to identify genetic markers for species identification, and will be valuable for resolving phylogenetic relationships within the genus, family Dixidae and suborder Nematocera.

Description of the last instar larva and new contributions to the knowledge of the pupa of Dasyhelea mediomunda Minaya (Diptera, Culicomorpha, Ceratopogonidae).

The fourth instar larva of Dasyhelea mediomunda Minaya is described for the first time and a complete description of the pupa is provided, through use of phase-contrast microscope and scanning electron microscope. Studied specimens were collected in a pond connected to a small wetland "mallin" on the Patagonian steppe, Chubut province, Argentina.

Simuliidae (Diptera, Culicomorpha) no Brasil: XIII sobre Inaequaliumlundi sp. n / Brazilian simuliidae (Diptera, Culicomorpha): XIII about Inaequaliumlundi sp. n

É descrita uma nova espécie para o gênero Inaequalium (Coscarón & Wygodzinsky, 1984), Inaequaliumlundi sp.n. É proposto um novo grupo de espécies dentro de Inaequalium. Os imaturos de Inaequaliumlundi sp.n. foram coletados em cursos d'água em uma altitude de 2.800 m no complexo geológico denominado Pico da Neblina, Amazonas, Brasil.

A new species is described for the genus Inaequalium (Coscarón & Wygodzinsky, 1984), Inaequaliumlundi sp.n. A new group of species is proposed inside of Inaequalium. The immature of Inaequaliumlundi sp.n. were collected in running waters located in 2.800 meters of altitude, in the geological complex of the "Pico da Neblina", Amazon state, Brazil.

Predação e foresia (ocasional?) entre imaturos de Simuliidae (Diptera: Culicomorpha) e Asolene (Pomella) Megastoma (Sowerby, 1825) (Mollusca: Gastropoda: Ampullaridae) / Predation and phoretic association (occasional?) among immature stages of Simuliidae (Diptera: Culicomorpha) and Asolene (Pomella) megastoma (Sowerby, 1825) (Mollusca: Ampullaridae)

The predation and phoretic association (occasional?) among simulids and mollusks are being registered here for the first time on the Neotropical region. These inter-relations observations were obtained among Asolene (Pomella) megastoma (Sowerby, 1825) and the simulids: Simulium (Thyrsopelma) Orbitale Lutz, 1910; Simulium (Psaroniocompsa) spp. The material studied is proceeding from the Uruguai river Hidrological Basin. Based on the mollusks natural habitat, it is here suggested his use as a possible integrated management element for simulids species which immature stages live on mighty river with rocks.