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Maritime chironomid midges (Diptera) are diverse, yet these ‘pearls of the ocean’ are little known. Emphasizing Pacific Ocean taxa, we used six genetic markers (18S, 28S, CAD1, CAD4, FolCOI and COI) and fossil calibrations to produce Bayesian timecalibrated phylogenies to date eight independent marine transitions in three subfamilies. Deep nodes involve subfamily Telmatogetoninae (originating mid-Cretaceous, 101–128, 114 Ma), with sister genera Telmatogeton Schiner and Thalassomya Schiner splitting later in the Cretaceous (56–82, 69 Ma). Two transitions in Orthocladiinae involve Clunio Haliday and Pseudosmittia Edwards, dating from the upper Cretaceous, both with Eocene crown groups. In subfamily Chironominae, transitions to marine occur in two tribes. Four transitions occur within the otherwise nonmarine crown groups Kiefferulus Goetghebuer, Dicrotendipes Kieffer, Polypedilum Kieffer and Ainuyusurika Sasa & Shirasaka. Two separate robust clades in tribe Tanytarsini involve: (1) a minor radiation within Paratanytarsus dated to the mid-Eocene around 43 Ma; and (2) an unexpected but fully supported diversification in Pontomyia Edwards plus Yaetanytarsus Sasa dated to around 47 Ma, with separation of Pontomyia from Yaetanytarsus around 40 Ma. Crown Pontomyia, represented by three species, was estimated to have diverged around 19 Ma, whereas the crown radiation of Yaetanytarsus, with 12 sampled species, dates to the mid-Eocene. In a comprehensive global review we concisely document new synonymies and new combinations revealed by the study. The evolutionary timing estimate provides insights into the frequency of marine transitions and diversifications in the Chironomidae in association with dynamic oceanic changes during the Oligocene and Miocene. [ABSTRACT FROM AUTHOR]

The newly discovered larva and previously unassociated pupa of Xiaomyia Sæther & Wang, a distinctive outlier in the subfamily Chironomidae, allows description, illustration and comparison with its proposed closest relative, Shangomyia Sæther & Wang. A previously described bizarre pupal exuviae, 'Taxon 2' sensu Coffman et al. (1988) from south India belongs to Xiaomyia. Molecular data from other sources allows review of the phylogeny and an estimate of the evolutionary tempo. As proposed for the pupa, and independently from adult male morphology, molecular data locate the two genera in a clade that is the sister group to the three other named tribes combined, warranting tribal status within the subfamily Chironominae. Expanded and revised diagnoses for larva, pupa, and adults of Xiaomyiini new tribe are provided. A novel ribbed and spinulose plate-like lobe associated with the ventral larval maxilla in Shangomyia and Xiaomyia is a major synapomorphy for the tribe. [ABSTRACT FROM AUTHOR]

The Afrotropical-Australian-Indomalayan genus Conochironomus Freeman, 1961 is here recorded for the first time from China, with the description of Conochironomus jat sp. nov. based on an adult male collected from Hainan Province and redescription of C. nuengthai Cranston, 2016 based on associated material collected from Guangdong Province. Three unassociated pupal exuviae collected from Yunnan and Hainan Provinces are also described. In addition, keys to adult males and pupae of Indomalayan Conochironomus are provided. [ABSTRACT FROM AUTHOR]

A chironomid-based calibration training set comprised of 100 lakes from south-western China was established. Multivariate ordination analyses were used to investigate the relationship between the distribution and abundance of chironomid species and 18 environmental variables from these lakes. Canonical correspondence analyses (CCAs) and partial CCAs showed that mean July temperature is one of the independent and significant variables explaining the second-largest amount of variance after potassium ions (K+) in 100 south-western Chinese lakes. Quantitative transfer functions were created using the chironomid assemblages for this calibration data set. The second component of the weighted-average partial least squares (WA-PLS) model produced a coefficient of determination (r2bootstrap) of 0.63, maximum bias (bootstrap) of 5.16 and root-mean-square error of prediction (RMSEP) of 2.31 °C. We applied the transfer functions to a 150-year chironomid record from Tiancai Lake (26°38'3.8 N, 99°43' E; 3898ma.s.l.), Yunnan, China, to obtain mean July temperature inferences. We validated these results by applying several reconstruction diagnostics and comparing them to a 50-year instrumental record from the nearest weather station (26°51029.22" N, 100°14'2.34" E; 2390ma.s.l.). The transfer function performs well in this comparison. We argue that this 100-lake large training set is suitable for reconstruction work despite the low explanatory power of mean July temperature because it contains a complete range of modern temperature and environmental data for the chironomid taxa observed and is therefore robust. [ABSTRACT FROM AUTHOR]

Djalmabatista sinica sp. n. is described and figured based on the adult male and pupa. The male can be separated from its congeners by the characteristic banded wing and the abdominal coloration, while the pupa differs from other species in the setal arrangement on abdominal segment III and the shape of the thoracic horn and the anal lobe. In addition, the pupa of D. reidi (Freeman, 1955) collected in China is briefly redescribed and a new distribution record is given. [ABSTRACT FROM AUTHOR]

Chironomid based calibration training sets comprised of 100 lakes from southwestern China and a subset of 47 lakes from Yunnan Province were established. Multivariate ordination analyses were used to investigate the relationship between the distribution of chironomid species and 15 environmental variables from these lakes. Canonical correspondence analyses (CCAs) and partial CCAs showed that mean July temperature is the sole independent and significant (p < 0.05) variable that explains 16 % of the variance in the chironomid data from the 47 Yunnan lakes. Mean July temperature remains one of the independent and significant variables explaining the second largest amount of variance after potassium ions (K+) in the 100 south-western Chinese lakes. Quantitative transfer functions were created using the chironomid assemblages for both calibration data sets. The first component of the weighted average partial least square (WA-PLS) model based on the 47 lakes training set produced a coefficient of determination (r²jack) of 0.83, maximum bias (jackknifed) of 3.15 and root mean squared error of prediction (RMSEP) of 1.72 °C. The two-component WA-PLS model for the 100 lakes training set produced an r²bootstrap of 0.63, maximum bias (bootstrapped) of 5.16 and RMSEP of 2.31 °C. We applied both transfer functions to a 150-year chironomid record from Tiancai Lake (26°38'3.8 N, 99°43'E, 3898 m a.s.l), Yunnan, China to obtain mean July temperature inferences. The reconstructed results based on both models showed remarkable similarity to each other in terms of pattern. We validated these results by applying several reconstruction diagnostics and comparing them to a 50-year instrumental record from the nearest weather station (26°51'29.22"N, 100°14'2.34"E, 2390 m a.s.l). Both transfer functions perform well in this comparison. We argue that the large training set is also suitable for reconstruction work despite the low explanatory power of MJT because it contains a more complete range of modern temperature and environmental data for the chironomid taxa observed and is therefore more robust. [ABSTRACT FROM AUTHOR]

Three new species of Nilothauma Kieffer are described and figured from Oriental China: N. angustum sp. n. based on the male only, N. aristatum sp. n. based on the male, pupa and larva, and N. bilobatum sp. n. based on the male and pupa. In addition, new distribution records are given for N. japonicum Niitsuma, N. nojirimaculatum Sasa, N. hibaratertium Sasa, and N. acre Adam & Sæther. A key to known males of Nilothauma Kieffer in China is provided. [ABSTRACT FROM AUTHOR]

The male of Microchironomus trisetifer (Hashimoto, 1981) is redescribed. The pupa of M. trisetifer and the larva and pupa of M. tabarui Sasa, 1987 are described for the first time based on material collected from southern China. Immature stages of M. tabarui deviate considerably from the previous generic concept. An emended generic diagnosis and keys to the known males and pupae are also provided. [ABSTRACT FROM AUTHOR]

Abstract The genus Nilothauma Kieffer, 1921 (Chironomidae: Chironominae) from China is revised. Nilothauma quatuorlobum sp. n. is described as male imago. N . acre Adam & Sæther, N . japonicum Niitsuma and N . nojirimaculatum Sasa are re-examined. One unplaced larva from Liaoning Province is described and illustrated. A key to males of Chinese species is given and systematics are discussed. [ABSTRACT FROM AUTHOR]

The pupa and larva of Propsilocerus taihuensis (Wen, Zhou & Rong, 1994) are described for the first time. Both are close to P. akamusi (Tokunaga). The phylogenetic argumentation of the genus outlined in Sæther and Wang (1996) is confirmed. Revised keys to larvae and pupae of the genus are given. The main morphological characters of the different species of the genus are compared in tables. [ABSTRACT FROM AUTHOR]