The taxonomy and distribution of the genus Hybos Meigen in the Palaearctic Region is reviewed with a special reference to the European fauna. Twenty-three species have been recorded from the Palaearctic, of which only four species are known from Europe. We describe two new species, H. andradei sp. nov. (Portugal) and H. mediasiaticus sp. nov. (Middle Asia). The status of two previously considered doubtful species of Hybos are validated: H. striatellus Villeneuve, 1913 (Algeria) and H. vagans Loew, 1874 (the Caucasus). Both species are re-described, and the lectotype of H. striatellus is designated. A key to species of Hybos from the western Palaearctic is compiled. Numerous new data on distributions of H. culiciformis (Fabricius, 1775), H. femoratus (Müller, 1776), H. grossipes (Linné, 1767) and H. vagans are given. Hybos culiciformis is recorded for the first time from Algeria, Byelorussia, Croatia, Cyprus, Lebanon, and Portugal; H. femoratus—from Estonia, Georgia (including Abkhazia), Kazakhstan, Mongolia and Ukraine; H. grossipes—from Byelorussia, Estonia, Kazakhstan, Latvia, Mongolia, Ukraine; H. vagans—from Armenia, Azerbaijan, Georgia (including Abkhazia), Russia, Turkey. The variation of some characters in H. culiciformis is discussed and is confirmed for Portugese specimens by COI barcoding. Female postabdominal structures are examined and described for H. andradei sp. nov., H. culiciformis, H. femoratus, H. grossipes, H. mediasiaticus sp. nov., and H. striatellus. Possible relationships of the West-Palaearctic species are discussed. A check-list of Hybos from the Palaearctic Realm is provided.

The genus Rhaphium Meigen, 1803 is recorded for the first time from mangroves in Hong Kong. Three species are described as new to science: Rhaphium hongkongense sp. nov. and Rhaphium spinulatum sp. nov., both tentatively belonging to the Rhaphium crassipes group sensu Negrobov & Grichanov (2010), and Rhaphium canniccii sp. nov. assigned to a new species group, the Rhaphium micans group. The status of Rhaphium mediocre (Becker, 1922) described from Taiwan and Rhaphium eburnea (Parent, 1926) from Shanghai is discussed. NGS barcodes for the new species are provided.

This is the first comprehensive introduction to the flies of the subfamily Tachydromiinae (Hybotidae) of Singapore. The monograph summarizes all publications on the Tachydromiinae of Singapore and includes new data resulting from mass-trapping surveys made in Singapore during the last six years. A few samples from Malaysia (Johor province, Pulau Tioman and Langkawi) have been also included in this study. In Singapore the Tachydromiinae are the most diverse group of Empidoidea (except Dolichopodidae) and currently comprise 85 species belonging to the following nine genera: Platypalpus (1), Tachydromia (1), Chersodromia (6), Pontodromia (1), Drapetis (5), Elaphropeza (60), Crossopalpus (1), Nanodromia (3) and Stilpon (7). All species are diagnosed and illustrated. The following 28 species are described as new for science: Chersodromia bulohensis sp. nov. (Singapore), C. glandula sp. nov. (Singapore, Malaysia), C. malaysiana sp. nov. (Singapore, Malaysia), C. pasir sp. nov. (Malaysia), C. sylvicola sp. nov. (Singapore), C. tiomanensis sp. nov. (Malaysia), Crossopalpus temasek sp. nov. (Singapore), Drapetis bakau sp. nov. (Singapore, Malaysia), D. hutan sp. nov. (Singapore), D. laut sp. nov. (Singapore, Malaysia), D. mandai sp. nov. (Singapore), D. pantai sp. nov. (Singapore, Malaysia), Elaphropeza chanae sp. nov. (Singapore), E. collini sp. nov. (Singapore), E. gohae sp. nov. (Singapore), E. kranjiensis sp. nov. (Singapore), E. lowi sp. nov. (Singapore), E. semakau sp. nov. (Singapore), E. shufenae sp. nov. (Singapore), Nanodromia hutan sp. nov. (Singapore), N. spinulosa sp. nov. (Singapore), Platypalpus singaporensis sp. nov. (Singapore), Pontodromia pantai sp. nov. (Singapore), Stilpon arcuatum sp. nov. (Singapore), S. neesoonensis sp. nov. (Singapore), S. nigripennis sp. nov. (Singapore), S. singaporensis sp. nov. (Singapore), S. weilingae sp. nov. (Singapore). A redescription is given for Crossopalpus exul (Osten-Sacken, 1882) (Taiwan). Males of Elaphropeza feminata Shamshev & Grootaert, 2007 and E. modesta Shamshev & Grootaert, 2007 as well as females of Elaphropeza ubinensis Shamshev & Grootaert, 2007 and Nanodromia narmkroiGrootaert & Shamshev, 2003 are described for the first time. Keys to genera and species, which are generally applicable to the whole of Southeast Asia, are compiled. An analysis of the species ecological preferenda is presented.

The first records on the genus Platypalpus Macquart from Thailand are presented including 10 species new to science: P. fai sp. nov., P. gaemluang sp. nov., P. hualuang sp. nov., P. isaanensis sp. nov., P. nuadkhao sp. nov., P. phomyaaw sp. nov., P. seedam sp. nov., P. seeluang sp. nov., P. siamensis sp. nov., and P. thaicus sp. nov.. A key to these species is provided. All species of Platypalpus known from the Oriental Region (totally 54) are arranged into the species groups currently established for the genus. Eight species groups are recognized from the Oriental Realm and the distribution of each group is briefly discussed. The P. albiseta‐group is most diverse in the Orient with 16 species recorded. Two species of this group possess a modified structure and vestiture of certain abdominal segments that is the first record of this phenomenon in Platypalpus. Also, within the P. albiseta‐group a complex of closely related species sharing an apomorphous condition of the hypoproct has been recognized. In these species the structure of the hypoproct is likely to deal with clasping during copulation instead of the cerci and epandrial lamellae.

The following 8 species are described as new to science: Chrysotimus acutatus Wang, Yang and Grootaert, sp. nov., C. chikuni Wang, Yang and Grootaert, sp. nov., C. guangdongensis Wang, Yang and Grootaert, sp. nov., C. ningxianus Wang, Yang and Grootaert, sp. nov., C. sanjiangyuanus Wang, Yang and Grootaert, sp. nov., C. songshanus Wang, Yang and Grootaert, sp. nov., C. xiaohuangshanus Wang, Yang and Grootaert, sp. nov., C. xuae Wang, Yang and Grootaert, sp. nov. A key to the Chinese species of the genus is presented.

Phylogenetic inference, based on five molecular markers (COI, 28S, AATS, 12S, PGD), corroborates the synonymy of the flightless genera Pieltainia Arias, 1919 and Ariasella Gil, 1923 with Tachydromia Meigen, 1803. The secondary structure of the 28S rRNA gene is used for the first time in this family to align the multiple sequences. Molecular and morphological data are largely congruent for all known species of flightless Tachydromia. This paper treats ten western Mediterranean species (nine Iberian and one Italian) in detail, including the description of four new species: T. ebejeri Goncalves, Grootaert & Andrade sp. nov., T. stenoptera Goncalves, Grootaert & Andrade sp. nov., T. cantabrica Goncalves, Grootaert & Andrade sp. nov. and T. nigrohirta Goncalves, Grootaert & Andrade sp. nov. The male of Tachydromia pieltaini (Gil Collado, 1936) and the female of Tachydromia apterygon Plant & Deeming, 2006 are described for the first time, while a lectotype is assigned to Tachydromia pandellei (Seguy, 1941). A key to all non-macropterous Tachydromia is supplied. Knowledge on the geographic distribution of most species is considerably enhanced. The mating behaviour of Tachydromia semiaptera (Gil Collado, 1923) and Tachydromia iberica (Arias, 1919) is documented for the first time, and we propose a change in the definition of terms apterous and micropterous to properly accommodate the diversity of wing states in this cluster of species.