Xylota xanthotarsis, Jeong & Han, 2019

Jeong, Soo-Hyun & Han, Ho-Yeon, 2019, A taxonomic revision of the genus Xylota Meigen (Diptera: Syrphidae) in Korea, Zootaxa 4661 (3), pp. 457-493 : 482-485

publication ID	https://doi.org/ 10.11646/zootaxa.4661.3.3
publication LSID	lsid:zoobank.org:pub:28EFDB26-4C37-4DA9-ABBB-122083EE396B
persistent identifier	https://treatment.plazi.org/id/5A219B24-345D-4724-FCED-FCB89ECC13D1
treatment provided by	Plazi
scientific name	Xylota xanthotarsis
status	sp. nov.

Treatment

Xylota xanthotarsis View in CoL sp. n.

(Korean name: no-rang-da-ri-heo-ri-kkot-deung-e)

Figs 1G, H View FIGURE 1 , 2G, H View FIGURE 2 , 7 View FIGURE 7 J–R, 12I–L, 13I

Diagnosis. Xylota xantotarsis is similar to X. pseudoignava , especially by sharing the silvery pilose patched abdomen ( Fig. 2I, J View FIGURE 2 ), while other similar dark colored Korean species have yellowish or white pilose abdominal patches. The former species can be further distinguished from the latter by the following combination of characters: 1) metatarsus pale yellow ( Fig. 7L, M View FIGURE 7 ); 2) postalar callus of scutum with sparse or no black pile; and 3) hypandrium of male genitally ventrally with a weak hump ( Figs 12J, K View FIGURE 12 , 13I View FIGURE 13 ). See Diagnosis of X. pseudoignava .

Description. MALE. Body length 12.9–14.9mm; wing length 9.9–10.6mm. Head black ( Fig. 7O, P View FIGURE 7 ); face heavily covered with white pollinosity but slightly bare under antenna; posterior 1/3 of male frons anterior to eye contiguity with yellowish pollinosity ( Fig. 1G View FIGURE 1 ); area anterior to ocellar triangle (vertical triangle anterior to ocellar triangle) bare but posterior area covered with yellow pile ( Fig. 1G View FIGURE 1 ). Thorax entirely black; scutum subshiny black, covered with short appressed yellow pile, but posterior half sparsely with longer erect yellow pile mixed with short pile; anterior anepisternum covered with yellowish pollinosity; posterior anepisternum with yellowish pollinosity and light yellowish pile (upper 1/2 area mixed with yellow pile) anepimeron mostly covered with white pile but upper 1/3 yellow pile; katepisternum moderately covered with yellowish white pollinosity, dorsal posterior area with white pile; notopleuron with brownish yellow pile; scutal area anterior to wing base with yellow pile with few black pile mixed; postalar callus mainly with long pale yellow pile and only anterior area with few black pile; metasternum bare with yellowish brown pollinosity. Wing hyaline except for brown pterostigma; halter pale yellow. Legs: pro- and mesotibiae yellow and subapico-ventral 4/5 dark brown to black; pro- and mesotarsomere 1–3 yellow, tarsomeres 4 and 5 black; male metatrochanter ventrally with elongated and sharp calcar (at least twice as long as basal width) ( Fig. 7L View FIGURE 7 ); apico-ventral 1/3 of metafemur with two carinae covered with spinose setulae, remaining apical 4/5 areas with two irregular rows of spinose setae (anterior row cover whole length but posterior row reach 2/3 length); antero-dorsally and postero-ventrally with long white pile, apico-dorsal 1/3 area with black setulae; metatibia dark brown to black and basal 1/3 yellow ( Fig. 7L View FIGURE 7 ); metatarsomeres 1–3 yellow, tarsomeres 4 and 5 black ( Fig. 7L View FIGURE 7 ). Abdomen about 4x longer than wide ( Figs 2G View FIGURE 2 , 7J View FIGURE 7 ), terga 2 and 3 almost parallel-sided ( Figs 2G View FIGURE 2 , 7J View FIGURE 7 ); terga 2–4 black with pair of lateral facing silvery gray pollinose triangular areas covered with white erect pile (other areas of terga with short appressed black pile) ( Fig. 2G, H View FIGURE 2 ). Male genitalia ( Figs 12 View FIGURE 12 I–L, 13I): surstylus with dorsal lobe elongated about twice as long as ventral lobe, long finger shaped and slightly bent ventrally in lateral view, densely covered with setulae ( Fig. 12J, K View FIGURE 12 ); ventral lobe of surstylus widely bulged with apex setulose ( Fig. 12J, K View FIGURE 12 ); cercus cordated in profile with long pale pile ( Fig. 12 View FIGURE 12 I–K); lingula indistinct ( Fig. 13I View FIGURE 13 ); fenestra round in outline ( Fig. 12J, K View FIGURE 12 ); spur of superior lobe reduced ( Fig. 13I View FIGURE 13 ); superior lobes symmetrical ( Fig. 12J, K View FIGURE 12 ); lateral arms of theca about apical half with sparsely scattered spiny setulae, dorsally rounded, apico-ventrally with short tiny protrusion; lateral arms of theca and hypandrium ventrally separated by deep invagination ( Fig. 12J, K View FIGURE 12 ); hypandrium ventrally with small protrusion ( Fig. 12J View FIGURE 12 ); aedeagus with ejaculatory hood medially with furrow in postero-ventral view, dorsally round ( Fig. 12L View FIGURE 12 ); ejaculatory process short ( Fig. 12L View FIGURE 12 ); ejaculatory apodeme apically enlarged and bowl shaped.

FEMALE. Similar to male except for the following non-genitalic characters: Head ( Fig. 1H View FIGURE 1 ): frons with about anterior 1/3 shiny black and bare with posterior 2/3 shiny black and covered with yellowish pile, medially with pair of areas of white pollinosity, except for narrow longitudinal bare area; area anterior to ocellar triangle (small area immediately anterior to ocellar triangle) bare but posterior area covered with yellow pile. Leg ( Fig. 7M View FIGURE 7 ): metatrochanter without calcar. Abdomen ( Fig. 2H View FIGURE 2 ): terga 2 and 3 almost parallel-sided but medially widen.

Type material. HOLOTYPE: ♂, South Korea, Gangwon-do , Hongcheon-gun , Nae-myeon, Daedong, Mt. Gye- bangsan, 6.VIII.1997, HY Han et al. ( NIBR) . PARATYPES: 1♂, South Korea, Gangwon-do : 1♂, Chuncheon-si, Nam-myeon, Balsan-ri , 300m, N37°43’29” E127°37’73”, Malaise trap in forest in shade, Tripotin rec., 17.V.– 6.VI.2006, M. Hauser ( CSCA); 1♂ Hongcheon-gun, Nae-myeon, Daedong, Mt. Gyebangsan, 6.VIII.1997, HY Han et al. ( NIBR); 1♀, ditto, 6.VIII.1997 HY Han et al. ( NIBR); 1♂, Jeongseon Nam-myeon, Mt. Mindungsan from Yupyeong-ri to 1119m peak, 37°16‘10“ N 128°46‘49“ E, 9.VIII.2001, HY Han et al. ( NIBR) ; 1♂, ditto, 19.VII.2005 HY Han and KE Ro ( YSUW) ; 1♀, Samcheok, Dogye-eup, from Sinbangteo to Mt. Dohwasan , 925m, 8. VI .2003, DS Choi et al. ( YSUW) ; 1 ♂, Wonju-si, Heungeop-myeon, Maeji-ri , Yonsei Univ. Wonju Campus , 10. VI .1996, HW Byun ( YSUW) ; 1♀, ditto, 7. VI .2003, DS Choi and HW Byun. Jeollanam-do: Gwangyang-si, Ongnyong-myeon, Mt. Baegunsan from Jinteul , 35°6‘23“N, 127°37‘17“E, 23. VI .2015, YB Lee et al. ( YSUW) ; 2♂, ditto, 31.V.2006, HY Han et al. ( YSUW) ; 8♂, ditto, 6. VI .2006, HY Han et al. ( YSUW) ; 1♂, ditto, 20. VI .2006, HY Han et al. ( YSUW) ; 1♂, ditto, 7.VII.2007, HY Han et al. ( YSUW) , 1♂, ditto, 13. VI .2008, HS Lee et al. ( YSUW) ; 2♂, ditto, 27. VI .2008, JS Lim et al. ( YSUW) ; 1♂, ditto, 12.V.2012, HY Han et al. ( YSUW) ; 1♂, Samcheok Dogye-eup from Sinbangteo to Mt. Dohwasan , 925m, 1.VIII.2003, DS Choi et al. ( YSUW) .

Distribution. Korea.

Remarks. In the Palaearctic region, X. pseudoignava and X. caeruleiventris Zetterstedt, 1838 appear to be most closely related to this new species by sharing the silvery pilose patched abdominal tergites 2–4 and very similar male genitalia (i.g., Figs 11 View FIGURE 11 E–H vs. 12 I–L). Separation of this new species is based on the pale yellow basal tar- someres of the metatarsus while the other two species have an entirely dark-brown metatarsi, in addition to their slightly but significantly different male genitalic structures (See Diagnosis of X. pseudoignava and X. xanthotarsis sp. n.). Another species, X. jakutorum Bagatshanova, 1980 , seems to be also closely related to the new species because it also has similar male genitalia (especially the hump on hypandrium; illustration of Vujić & Milankov, 1999: 125). This species can be easily separated by the light colored abdominal pattern in dark background in males from the above three species.

Etymology. The specific epithet is an adjective derived from the Greek ‘ xantho’ meaning yellow, and the Greek ‘ tarsi’ meaning tarsus, referring to yellow metatarsus.