Loxocera (Loxocera) lonsdalei, Zhou & Yang, 2023

Zhou, Jiale & Yang, Ding, 2023, A review of the subgenus Loxocera Meigen, 1803 (Diptera, Brachycera, Psilidae) in China, ZooKeys 1186, pp. 71-96 : 71

Loxocera (Loxocera) lonsdalei sp. nov.

Figs 9-10 , 11-13 , 14-17

Type materials.

Holotype (♂): China, Shaanxi, Xi’an, Huyi, Zhuque Forest Park, 2606 m, 2020.vii.10, leg. Bing Zhang (CAU). Paratypes: China, Qinghai, Haibei, Menyuan, Deqian vill., 2725 m, 2019.vii.18, leg. Jinlong Ren (1♀, CAU); China, Qinghai, Haidong, Huzhu, Beishan Forest Farm, Zhalonggou, 2724 m, 2019.vii.2, leg. Qilemoge (1♂1♀, CAU); CHINA, Qinghai, Haidong, Huzhu, Yuanfugou, 2682 m, 2019.vii.3, leg. Qilemoge (1♀, CAU); same collection data as for holotype (5♂5♀, CAU); China, Shaanxi, Xi’an, Zhouzhi, Wangjiahe, 1165 m, 2020.vii.6, leg. Bing Zhang (1♀, CAU).

Diagnosis.

Generally brown to blackish brown; face yellowish brown; antennal pedicel distinctly longer than scape; antennal first flagellomere about 3 times as long as pedicel, gradually narrowed towards apex; arista whitish yellow, thin, arising near midpoint of antennal first flagellomere and 1.3 times as long as the latter; mesonotum blackish, with irregular brownish margin; wing without transverse dark band; hypandrial lobe large, broad, covered with short setae; pregonite short, simple in shape, apically blunt; phallus shovel-like, relatively long, abruptly widened apically with rounded posterior margin.

Description.

Male and female. Body length 7.7-9.5 mm, wing length 6.0-6.5 mm, length of antenna 1.6-1.8 mm. Generally brown to blackish brown, moderately shining (Figs 9 , 10 ). Frontal vitta black, with anterior part brown (Fig. 11 ); ocellar triangle and face yellowish brown; parafacial, gena and posterior eye margin dark yellow (Figs 11 , 12 ). Antenna with arista whitish yellow (Fig. 12 ). Proboscis and palpus pale brown. Postpronotum brown to dark brown. Mesonotum largely blackish brown, with irregular brown to dark brown margin as shown in Fig. 13 . Scutellum yellowish brown (Fig. 13 ). Mesopleuron dark yellow with variable brown to dark brown mottling (Fig. 10 ), or largely blackish brown (Fig. 9 ). Wing slightly infumated; wing veins yellowish brown to dark brown. Halter white with base slightly darkened. Legs dark brown to blackish brown; coxae brown to blackish brown; trochanters, apex of femora, tibiae, and tarsi yellowish brown; mid tibia with indistinct, narrow, dark ring subapically (Figs 9 , 10 ); hind tibia with wide dark ring at middle (Figs 9 , 10 ). Abdomen yellowish brown; anterior half and posterior margin of syntergite 1+2 and posterior portion of tergites 3-5 in male blackish brown (Fig. 9 ); anterior half and posterior margin of syntergite 1+2 and posterior portion of tergites 3-6 in female dark brown, posterior half of tergite 7 and anterior half of tergite 10 blackish brown (Fig. 10 ). Bristles on head and thorax black.

Head (Figs 11 , 12 ) nearly rounded in dorsal view, largely glabrous; length along midline 0.9 times as long as width across eyes, width across eyes 2 times as broad as interocular space. Frons strongly protruding beyond level of anterior eye margin; frontal vitta with shallow depression at middle; frontal orbit with some short, scattered hairs. Ocellar triangle broad, smooth. Face strongly slanting, with weakly elevated median carina. Parafacial narrow, with a tomentose golden patch between anterior eye margin and lunule. Gena swollen; postgena covered with silvery tomentum. Occiput with a large silvery tomentose patch at middle above foramen. Head chaetotaxy: 1 ocellar seta, 1 postvertical seta, 1 inner vertical seta, 1 outer vertical seta. Antenna (Fig. 12 ) long and thick, with short dense setulae; pedicel distinctly longer than scape; first flagellomere about 3 times as long as pedicel, gradually narrowed towards apex; arista thin, arising near midpoint of first flagellomere, 1.3 times as long as first flagellomere, divided into small aristomere 1 and large aristomeres 2+3. Palpus elongate oval, with short dense golden setulae and long scattered black setae.

Thorax (Figs 9 , 10 , 13 ) robust, with short dense whitish yellow setulae, except anepisternum (anterior half), anepimeron, katatergite, katepisterum (middle portion), meron, scutellum and mediotergite (middle portion) glabrous; anatergite with fine tomentum. Scutum 1.2 times as long as wide. Scutellum (Fig. 13 ) subtriangular, slightly swollen and wider than long. Thoracic chaetotaxy: 1 dorsocentral seta, 1 notopleural seta, 2 posterior supra-alar setae, 1 apical scutellar seta. Wing with last sector of M1 strongly curved; apex of M4 nearly reaching wing margin. Legs with dense, whitish-yellow setulae, except ventral surface of fore and mid femora largely glabrous; femora subfusiform, slightly compressed laterally; tibiae gradually widened towards apex, nearly straight.

Abdomen elongate, with short, dense, whitish-yellow setae; syntergite 1+2 with several long hair-like setae laterally.

Male genitalia: Sternite 8 (Figs 14 , 15 ) broad, relatively flattened, with long, dense setae. Cerci (Figs 14 , 15 ) relatively slender, slightly curved, with short, dense setae. Hypandrium (Fig. 17 ) well developed; hypandrial arms posteriorly produced into very large, broad, convex lobes covered with short setae (Figs 14-17 ). Hypandrial bridge present and robust. Pregonite (Figs 14-16 ) short, simple in shape, apically blunt. Phallus (Figs 14 , 15 ) shovel-like, relatively long, abruptly widened apically with rounded posterior margin. Phallotrema (Fig. 16 ) large, flanked by peculiar, short or long, simple or apically bifurcate processes. Ejaculatory apodeme (Fig. 15 ) small, hook-like, strongly curved.

Female terminalia: Segment 7 laterally compressed; sternite 7 keeled along midline. Segment 8 coriaceous and longitudinally striate, posterodorsal margin shallowly emarginate, posterolateral margin forming blunt angular protrusion, posteroventral margin with deep linear incision. Tergite 10 relatively long and broad, with tiny, scattered setulae. Cerci relatively broad, separate from tergite 10, with rows of long setulae on posterior margin.

Etymology.

The specific epithet is dedicated to the Canadian entomologist Owen Lonsdale (Agriculture and Agri-Food Canada, Ottawa, Canada), for his outstanding contribution to the systematics of Acalyptratae , and his encouragement to the first author.

Distribution.

China - Qinghai: Haibei, Haidong; Shaanxi: Xi’an (Fig. 37 ).

Comparative notes.

This new species is most similar to L. (L.) omei Shatalkin, 1998, but it can be easily distinguished from the latter by the following character states: antennal pedicel distinctly longer than scape [vs subequal in length in L. (L.) omei ]; antennal first flagellomere distinctly narrowed towards apex [vs weakly narrowed in L. (L.) omei ]; mesonotum largely blackish with irregular brownish margin [vs uniformly blackish in L. (L.) omei ]; abdomen yellowish brown with distinct ring-like markings [vs blackish brown with apical segments reddish in L. (L.) omei ].

Antennal morphology similar to that of this new species also presents in L. (L.) hoffmannseggi Meigen, 1826 from Central and West Europe and L. (L.) matsumurai Iwasa, 1992 from Japan. However, the coloration of head, thorax, and abdomen of the new species is very different from that of the latter two species. Additionally, the head of the new species is nearly rounded in dorsal view with the frons strongly protruding anteriorly, while in the latter two species, the head is transverse oblong in dorsal view and the frons weakly protrudes anteriorly.

Figures

Figure 37. Known distribution of species of the subgenus Loxocera Loxocera in China.

Figures 9, 10. Loxocera (Loxocera) lonsdalei sp. nov., habitus, lateral 9 male, holotype 10 female, paratype. Scale bar: 3 mm.

Figures 11 - 13. Loxocera (Loxocera) lonsdalei sp. nov., paratype, female 11 head, dorsal 12 same, lateral 13 thorax, dorsal. Scale bar: 1 mm.

Figures 14 - 17. Loxocera (Loxocera) lonsdalei sp. nov., male genitalia 14 sternite 8 to genitalia, caudal 15 same, lateral 16 pregonite and phallus, ventral 17 hypandrium and associated structures, ventral. Abbreviations: ce = cercus, ea = ejaculatory apodeme, ep = epandrium, ha = hypandrial arm, hb = hypandrial bridge, hl = hypandrial lobe, pg = pregonite, s 8 = sternite 8, ph = phallus, pt = phallotrema. Scale bars: 0.25 mm (14, 15, 17); 0.1 mm (16).