Heterangaeus Alexander 1925, n. sp.

Heterangaeus Alexander, 1925

East Palaearctic genus Heterangaeus Alexander, 1925 has only eight species worldwide (including new species, described in this paper) (Table 2). Two of them have two subspecies each. Three species are known from the continent: H. gloriosus gloriosus, H. mongolicus and H. koreanus n. sp. Remaining species are endemic to Japan. Only H. gloriosus gloriosus has comparatively wide distribution, it is known not only from the continent, but also from Japan and Kuril and Sakhalin islands of Russia.

Not much can be said about biology and ecology of these species. Most species are known only from original descriptions and original specimens. Despite H. gloriosus kusunoki, H. palidellus and H. spectabilis were described from females, only ovipositor of H. mongolicus was illustrated (Podenas et.al. 2014). Larva is described only for H. mongolicus.

Characteristic morphological details of genus Heterangaeus were described by Alexander (1925), later updated by Alexander (1958), and a key for all species was given in the latter paper. Although half of species were known from females only, and no males were found, it is possible to describe most important structures, which could be used to characterize the genus (updated from Podenas et al. 2014, with addition of features from new species). Wings of all species have distinct spots, sometimes they are cross-banded (at the level of Rs base and at cord). Rs long, mostly angulated and spurred at base, sometimes arched. Vein R2+3 always angulated and short spurred at base. Additional cross-veins in cells r3, r4, m1 and m, sometimes also in r1. Discal cell always present. Cell m1 with or without short stem. Posterior wing margin could be very wavy, with deep incisions at tips of both anal veins and at posterior margin of second anal cell, but usually posterior wing margin smooth like in most crane flies. Wings of most species have large anal angle, but it could be very small due to narrow second anal cell. Antennal flagellum 10–11-segmented. Gonocoxite of male terminalia with wide rounded distal part, which sometimes is separated from the rest part of gonocoxite by narrower “neck“. Rounded distal part bears numerous small black spines. One pair of gonostyli, gonostylus with strong black subapical, or nearly so, spine. Aedeagus short, terminating in a capitate head, or long and extended into needle-like spine. Cercus of ovipositor wide with rounded tip turned upwards. Hypovalvae dorsally bear a row of 6–7 strong setae pointing caudally.

Larvae of genus Heterangaeus are known just for recently described species H. mongolicus (Podenas et al. 2014) Overall appearance of this genus is typical for subfamily Pediciinae. They have two spiracular lobes, which are almost three times as long as its basal width. Anus is surrounded by four white, short, fleshy and segmented anal papillae. Spiracular field is entirely covered with setae. Spiracles are small, oval in shape, close to each other and at the same level as spiracular field. Setae covering body are longer on tergites and forming longitudinal line interrupted by short pubescence on seventh abdominal segment. Creeping welts on 7th–10th segments laterally elevated into humps. General appearance of head capsule is the same as in other species in the family: well sclerotised, dorsally depressed, narrow and elongate in shape with curved dorsal sutures and straight frontoclypeal suture. Larvae of Heterangaeus have short antennae and two long apical papillae. Mandibles are large, sickleshaped, with well developed teeth, three dorsal and four ventral. Maxillae sclerotised and consists of well developed inner (galea) and outer (palpiger) lobes with distinctly arched cardo at the base. Hypostoma of H. mongolicus consists of two plates, each bearing three teeth. Push-button connection at the base of innermost teeth is not visible. During recent fieldwork in Korea larval specimens for H. koreanus sp. n. were discovered, which provided additional information on larval morphology of the genus Heterangaeus.

No fossil species of Heterangaeus were discovered so far (Evenhuis 1994).