Dicranophragma Osten Sacken, 1860

Podenas, Sigitas, Park, Sun-Jae, Byun, Hye-Woo, Kim, A-Young, Klein, Terry A. & Aukštikalnienė, Heung-Chul Kim and Rasa, 2020, New data on Limoniinae and Limnophilinae crane flies (Diptera: Limoniidae) of Korea, Journal of Species Research 9 (4), pp. 492-531 : 508-509

Dicranophragma Osten Sacken, 1860

Limnophila (Dicranophragma) Osten Sacken, 1860: 240- 241 ; Alexander, 1943: 381-382.

Dicranophragma Starý, Reuch, 2009: 209 .

Type species: Limnophila fuscovaria Osten Sacken, 1860 ( North America ) .

Adult.

Small crane flies with body length 4.5-7.5 mm and wing length 5.4-8.2 mm. Body coloration varies from yellow, gray, brown, to dark brown.

Head: Rounded posteriorly without neck-like extension. Vertex wide without or with small indistinct tubercle. Antenna 16-segmented, usually longer in male, reaching from frontal margin of prescutum to wing base, if bent backwards. Verticils long and distinct, longer than respective segments.

Thorax: Prothorax elongate. Mesonotal prescutum with small distinct separate tubercular pits at frontal margin, pseudosutural fovea distinct, sclerite usually with longitudinal stripes. Pleuron with bare katepisternum and small reduced meron, thus middle and posterior coxae close to each other. Wing long and narrow, cells without macrotrichiae. Venation: arculus missing, vein Sc long, reaching wing margin at or beyond branching point of Rs; Rs long, arched at base; cell r 3 with short stem; cell m 1 present, deep in some species, very small in other, sometimes missing in some specimens; discal cell always present, elongate; cross-vein m-cu close to the middle of discal cell. Anal vein long, slightly sinuous, reaching wing margin close to the level of Rs base. Anal cell long and narrow. Wing squama setoseless. All legs with tibial spurs, usually foreleg with single spur, middle and posterior legs with two spurs each.

Abdomen: Tergites with paired transverse sutures. Male terminalia approximately as wide as the rest abdominal segments, slightly elongate. Ninth tergite wider than longer, simple, without additional structures. Gonocoxite strongly elongate, more than twice as long as wide, interbase well developed, often spoon-shaped, two pairs of terminal gonostyli, outer gonostylus long and narrow, usually bidentate at apex, inner gonostylus fleshy and setose. Aedeagus usually short and straight, curved in D. ( Mixolimnomyia ) Savchenko, 1979. Ovipositor with long and narrow cerci and hypovalvae, distal part of cercus slightly raised upwards.

A total of 49 species belong to Dicranophragma worldwide ( Oosterbroek, 2020). They are divided into three subgenera, two of them, D. ( Brachylimnophila ) Alexan- der, 1966 and D. ( Dicranophragma ) Osten Sacken, 1860 occur in Korea, another, D. ( Mixolimnomyia ) ( Savchenko, 1979) has only one species, recorded from Caucasus Mountains only. No fossil species are described ( Evenhuis, 2014).

Larva.

Light brown, up to 8 mm long. Head capsule heavily reduced. Mandible large, sickle shaped. Maxilla elongate, inner and outer lobes fused. Hypopharyngeal bar present on ventral side. Spiracular disk surrounded by five short lobes and entirely fringed with short marginal hairs. Ventral lobe is the longest, dorsal short and blunt, sclerites on lateral and ventral lobes V-shaped, dorsal lobe not pigmented, but lined with longitudinal stripes, ventral lobe with long apical seta.

Pupa.

Length up to 6 mm. Head, pronotal horns, sheaths of wings and legs dark brown, abdomen light brown. Cephalic crest prominent. Pronotal horns short, cylindrical, slightly narrowed apically. Mesonotum unarmed. Wing sheaths short, reaching distal margin of second abdominal segment. Sheaths of legs reaching base of fourth abdominal segment. Abdominal segments divided by transverse groove into anterior and posterior parts, anterior part with eight slender tubercles on dorsal surface, posterior part with a transverse row of spines. Spiracles present. Terminal end of male blunt, with additional spines. Terminal segment of female elongated, with additional spines.

Preimaginal stages develop in rich organic mud.