OSMYLINAE Leach, 1815

Winterton, Shaun L., Martins, Caleb Califre, Makarkin, Vladimir, Ardila-Camacho, Adrian & Wang, Yongjie, 2019, Lance lacewings of the world (Neuroptera: Archeosmylidae, Osmylidae, Saucrosmylidae): review of living and fossil genera, Zootaxa 4581 (1), pp. 1-99 : 35-36

OSMYLINAE Leach, 1815

Type genus. Osmylus Latreille, 1802: 289 .

Diagnosis. Ocelli present, antennae shorter than half length of FW; prothorax width subequal to length; female forecoxae sometimes with narrow processes; trichosors present along most of wing margin; usually numerous FW forked subcostal veinlets, sometimes with interlinking crossveins; HW subcostal veinlets sometimes forked, particularly distally; single FW with single sc-r crossvein basally; RP with 10–17 branches, crossveins numerous and regularly spaced, rarely with crossveins almost completely absent in basal half of radial area (e.g., Sinosmylus ), RP branches only slightly sinuous distally; RP with outer and inner gradate series distinct in both wings, although inner series sometimes absent (e.g., Parosmylus , Lithosmylus ); FW M vein forked opposite or slightly distal (rarely basal, e.g., Parosmylus ) to origin of RP1; HW medial area slightly expanded basally, narrowed distally; marginal branches of M and Cu near perpendicular to wing margin, palisade-like in arrangement; CuA with more branches in HW than in FW; CuP in both wings elongate with numerous pectinate branches; male abdominal tergites 8 and 9 as separate sclerites with eversible scent glands present on membrane between; male genitalia with enlarged gonarcus, externally visible with distinct setal pile, anterior apodeme narrow and articulated upon gonarcus; entoprocesses reduced and rounded; parameres narrow rod-shaped sclerites flanking mediuncus; female genitalia with sternite 8 plate-like, positioned immediately posterior to sternite 7; gonopophysis 9 as lateral sclerites anterior to and closely associated with gonocoxite 9, articulated with tergite 9 ventrally. Larvae typically have a dark brownish-black body colour.

Comments. Osmylinae are closely related to Kempyninae and Stenosmylinae and share many morphological similarities with Kempyninae , especially in wing venation. Indeed, this similarity in wing venation has been problematic for placing fossil genera (e.g., Lithosmylus ) where typical discriminating wing vein characters at the subfamily level (e.g., branching pattern of subcostal veinlets, forewing media and hind wing cubitus) are the same in both Osmylinae and Kempyninae . Osmylinae occupy an intermediate position in the phylogeny of the family, sister to more derived subfamilies such as Kempyninae , Porisminae and Stenosmylinae and exhibit a variety of characters shared with other subfamilies (e.g., fusion of male tergites 8 and 9, eversible scent glands, presence of parameres, and position of female gonopophysis 9). Osmylinae comprise at least six morphologically similar genera, although some authors recognise up to eight. Unfortunately, characteristics useful in defining genera in this subfamily are relatively few in number, and those used are not adequate. This has resulted in very little consensus amongst various authors regarding generic concepts ( Banks, 1913; Nakahara, 1914; Kuwayama, 1953, 1962; Makarkin, 1985; Wang & Liu, 2009; Sekimoto, 2010; Xu et al., 2016), even amongst authors of this present work. Moreover, in their phylogenetic analysis of both molecular and morphological data, Winterton et al. (2017) confirmed the uncertain status of most genera in the subfamily, with Osmylus rendered paraphyletic by all other osmyline genera included in the study (i.e., Plethosmylus , Parosmylus and Sinosmylus ). Herein we diagnose the following genera but consider the status of all but the type genus Osmylus as uncertain and in need of further detailed study. Larvae are found in the air-water interface of riparian habitats.

Genera included. Grandosmylus Makarkin , Lahulus Navás , Lithosmylus Carpenter , Osmylus Latreille , Parosmylus Needham , Sinosmylus Yang.