Osmylus Latreille

Xu, Han, Wang, Yongjie & Liu, Zhiqi, 2016, Three new species of Osmylus Latreille from China (Neuroptera, Osmylidae), ZooKeys 589, pp. 107-121 : 109-113

Taxon classification Animalia Neuroptera Osmylidae

Genus Osmylus Latreille

Osmylus Latreille, 1802: 289. Type species: Hemerobius fulvicephalus Scopoli, 1763: 270.

Dictyosmylus Navás, 1910: 189. Type species: Dictyosmylus lunatus Navás, 1910: 189, by monotypy.

Diagnosis.

Moderate to large body size (body length 15-20 mm); forewing generally large and broad (length 20-30 mm), with numerous fragmentary marks; two nygmata present at the center and the proximal base of wing between MP and Rs; veins dark brown; costal cross-veins generally bifurcate distally, without interlinking veinlets; cross-veins among branches of Rs forming at least two series of gradates; MP forked close to the base, MP2 with many branches. The hindwing resembles the forewing in shape, but with fewer spots. The 9th tergite has variably-shaped dorsal process. Genitalia are composed of a gonarcus and a mediuncus; the gonarcus is variable in shape, consisting of a sclerotized and pilose external section posteriorly with a lightly sclerotized anterior-lateral section, the latter laterally with an anterior rod shaped process (i.e., baculum of some authors) which is sometimes articulated. The mediuncus (i.e., parameres of some authors) is curved with a fused base (although the shape is variable in Osmylus pachycaudatus ). The mediuncus is subtended laterally by the rod-shaped, paired parameres (i.e., subarcus of other authors) that are not fused anteriorly. The female 9th tergite occasionally has a ventral process, the gonapophysis lateralis is generally finger-like and articulated with stylus distally, and the spermatheca is either oval or cylindrical in shape.

Included species.

Osmylus angustimarginatus sp. n., Osmylus biangulus Wang & Liu, Osmylus bipapillatus Wang & Liu, Osmylus cilicicus Krüger, Osmylus conanus Yang, Osmylus decoratus Nakahara, Osmylus fuberosus Yang, Osmylus fulvicephalus (Scopoli), Osmylus gussakovskii Kozhanchikov, Osmylus hyalinatus McLachlan, Osmylus kisoensis Iwata, Osmylus lucalatus Wang, Osmylus maoershanicola sp. n., Osmylus megistus Yang, Osmylus minisculus Yang, Osmylus multiguttatus McLachlan, Osmylus pachycaudatus Wang, Osmylus posticatus Banks, Osmylus pryeri McLachlan, Osmylus shaanxiensis sp. n., Osmylus taiwanensis New, Osmylus tessellatus McLachlan, Osmylus wuyishanus Yang, Osmylus xizangensis Yang.

Comments.

Osmylus has been often confused with three other genera, Grandosmylus Makarkin, 1985, Parosmylus Needham, 1909 and Plethosmylus Krüger, 1913. Banks (1913) advanced that Parosmylus should be a junior synonym of Osmylus because the spur on the coxa in Parosmylus is also present in some species of Osmylus . Krüger (1913) erected the genus Plethosmylus based on venation characters (presence of interlink veinlets between costal cross-veins). Nakahara (1914) considered the opinion of Krüger subjective and synonymized the latter genus. Kuwayama (1953, 1962) again separated Plethosmylus , differentiating it from Osmylus by the presence of interlinking veinlets among the costal and two basal Rs-Mp cross-veins before the proximal nygma. However, Makarkin (1985) revised the status of Plethosmylus , synonymizing it with Osmylus and establishing a new subgenus Plesiosmylus within Osmylus . He also established a new genus Grandosmylus , separated from Osmylus by the irregular gradate cross-veins and the shape of 9th sternite in males and 8th sternite in females; this opinion was accepted by Sekimoto (2011) in his revision of Japanese Osmylus . The relationship among Grandosmylus , Parosmylus and Plethosmylus remains unclear. Wang and Liu (2009) clarified the generic status of Parosmylus , after reviewing specimens from mainland China, and they concluded that both genera could be valid due to differences in the number of gradate series, the configuration of gonarcus and the shape of spermatheca ( Wang and Liu 2009). Furthermore, after re-examining the specimens of Plethosmylus from mainland China, we observed that Osmylus and Plethosmylus possessed significant differences in male genitalia (the configuration of gonarcus) and in female genitalia. Moreover, the interlink veinlets among costal cross-veins could conveniently divide them. Considering the vague relationships among these genera, we consider is suitable to maintain them as separate genera until a robust phylogenetic work can be conducted in the future. In this paper, three new species of Osmylus are described from China: Osmylus maoershanicola sp. n. Osmylus shaanxiensis sp. n. and Osmylus angustimarginatus sp. n., primarily based on genital characters.

Key to Osmylus species in the Palaearctic and Oriental regions

(Note: Osmylus kisoensis is not included as it is only known from the larval stage, while Osmylus cilicicius and Osmylus posticatus are poorly known and could not be included in the key.)