9. Pseudacteon formicarum (Verrall)

(Figs. 11A–F, 12A–F)

Phora formicarum Verrall, 1877: 258.

Diagnosis. Female. Frons (11A) with 14–16 setulae; apical seta longer than maximum width of palpus; ratio of fore tarsomeres 0.79: 0.63: 0.63: 0.53: 1 (Fig. 11C); mid tibia without setal palisade (Fig. 11D); setulae below basal half of hind femur shorter than those of anteroventral row of outer half (Fig. 11E); wing (Fig. 11B) length 1.07 mm, width 0.54 mm, width/length 0.51; costa index 0.44, costal ratio 1.06:1, costal cilia 0.055–0.059 mm; tergite VI convex behind, with 3–4 setulae each side; sternite VI rectangular, not clearly defined, with 4–5 setulae each side (Fig. 11F); dorsum of oviscape comprising an irregular lateral row of about 12 small setulae each side (Fig. 13F). Male. Frons (Fig. 12A) with 18–20 setulae; apical seta longer than maximum width of palpus; ratio of fore tarsomeres 0.83: 0.56: 0.50: 0.50: 1 (Fig. 12C); mid tibia without setal palisade (Fig. 12D); setulae below basal half of hind femur shorter than that of anteroventral half (Fig. 12E); wing (Fig. 12B) length 1.05mm, width 0.5mm, width/length 0.48; costa index 0.36, costal ratio 1.31: 1, costal cilia 0.047–0.055 mm; abdominal tergites brown; terminalia (Fig. 12F) brown and anal tube pale yellow.

Distribution. China (Jilin, Liaoning, Gansu), Russia (Far East), Austria, Belgium, Czechs, Denmark, Finland, Slovakia, Sweden, Switzerland, Germany, France, Great Britain, Hungary, Norway, Spain, The Netherlands, Poland.

Specimens examined. 1♀, Jilin, Yanbian, Tuan (42°11′17.38″N, 128°10′24.65″E; 1120m), 31-July-2014, Jianfeng Wang; 1♀, Jilin, Yanbian, Wangqing (43°15′26.19″N, 129°55′35.23″E, 380 m), 8-Aug-2014, Jianfeng Wang; 2♀ (slide), Jilin, Yanbian, Wangqing (43°15′26.19″N, 129°55′35.23″E, 380 m), 8-Aug-2014, Jianfeng Wang; 1♀, Liaoning, Benxi, Mt. Wunv (41°19′58.76″N, 125°25′11.81″E), 16-Sep-2010, Jianfeng Wang; 1♀, Liaoning, Anshan, Yufeyuan (41°6′43.55″N, 123°1′28.74″E), 15-Aug-2018, Jiao Zhang; 2♀, Liaoning, Fushun, Mt. Houshi (41°43′53.76″N, 124°27′7.93″E), 17-Jun-2015. Lina Huang; 1♀, Liaoning, Fushun, Mt. Houshi (41°43′53.76″N, 124°27′7.93″E), 18-Jun-2015, Jianfeng Wang; 2♂ (slides), Liaoning, Tieling, Mt. Longshou (42°17′39.0″N, 123°51′47.50″E), 27-July-2018, Jiao Zhang; 2♀, Zhejiang, Mt. Tianmu (30°21′22.05″N, 119°26′39.90″E), 15-Jul-2012, Yiping Wang; 1♂ (slide), Gansu, Wen County, Guanegou (33°55′12″N, 104°14′21″E; 2478 m), 10-Aug-2011, Yunlong Cai; 1♀ (slide), Gansu, Tanchang County (33°59′56.95″N, 104°23′53.65″E), 9-Aug-2011, Yunlong Cai.

Remarks. This widely distributed species is different from all other species of the genus in having no palisade on mid tibia in both male and female.