Keilbachia acumina, Vilkamaa, Pekka, Menzel, Frank & Hippa, Heikki, 2009

Vilkamaa, Pekka, Menzel, Frank & Hippa, Heikki, 2009, Review of the genus Keilbachia Mohrig (Diptera: Sciaridae), with the description of eleven new species, Zootaxa 2272, pp. 1-20 : 3-4

Keilbachia acumina sp. n.

( Fig. 1 A–F)

Type locality: JAPAN: Honshu Island, Hyogo Pref., Mt. Hyonosen.

Material studied: Holotype male. JAPAN: Honshu Island, Hyogo Pref., Mt. Hyonosen, broad-leaved forest ( Fagus crenatus and bamboo), 1200 m a.s.l., sweep-net, 28.9.1995, leg. M. Jaschhof & T. Yagi ( SDEI). Paratypes: Honshu Island, Hyogo Pref., Mt. Hyonosen, broad-leaved forest (dominated by Fagus crenatus and bamboo), 1200 m a.s.l., sweep-net, 2 males, 28.9.1995, leg. M. Jaschhof & T. Yagi ( SDEI). Shikoku Island, Kochi Pref., Ashizuri Peninsula, Tosashimizu, Sata-yama Forest Reserve, 300–400 m a.s.l., primary evergreen broad-leaved forest (dominated by Castanopsis sieboldii ), sweep-net, 2 males, 9.11.1998, leg. M. Jaschhof ( SDEI). Shikoku Island, Kochi Pref., Yusuhara-cho, Takatori-yama Forest Reserve;, mixed primary forest (dominated by Abies firma, Chamaecyparis obtusa, Quercus spec., Cinnamomum spec.), 300–500 m a.s.l., sweep-net, 2 males, 5.11.1998, leg. M. Jaschhof ( SDEI). Kyushu Island, Kagoshima Pref., Higashiichiki, sweep-net, 1 male, 15.9.1998, leg. M. Sutou ( NSMT). Kyushu Island, Kagoshima Pref., Mt. Eboshi near Hirakawa, sweep-net, 1 male, 17.8.1998, leg. M. Sutou ( NSMT). Kyushu Island, Kagoshima Pref., Mt. Kinpou near Kumamoto, broad-leaved forest, 600 m a.s.l., sweep-net, 2 males, 18.9.1995, leg. M. Jaschhof ( SDEI). Kyushu Island, Kagoshima Pref., Sakurajima, sweep-net, 1 male, 11.7.1998, leg. M. Sutou ( NSMT). Honshu Island, Kanagawa Pref., Miura, Tsurugizaki, sweep-net, 2 males, 21.6.1998, leg. M. Sutou (1 male NSMT; 1 male PMSY). Honshu Island, Kanagawa Pref., Sagamiko, sweep-net, 1 male, 27.7.1998, leg. M. Sutou ( PMSY). Shikoku Island, Kochi Pref., Ashizuri Peninsula, Tosashimizu, Sata-yama Forest Reserve, 300–400 m a.s.l., primary evergreen broad-leaved forest (dominated by Castanopsis sieboldii ), sweep-net, 2 males, 9.11.1998, leg. M. Jaschhof ( SDEI). Kyushu Island, Kumamoto Pref., Aso, Mt. Aso National Park, coniferous forest (dominated by Cryptomeria japonica ), 700 m a.s.l., exhaustor or sweep-net, 11 males, 12.10.1995 or 14.10.1995, leg. M. Jaschhof (3 males KUEC; 6 males SDEI; 2 males MZH). Honshu Island, Kyoto Pref., Mt. Daimonji NW of Kyoto, mixed forest, exhaustor, 5 males, 26.10.1995, leg. M. Jaschhof (2 males KUEC; 3 males SDEI). Honshu Island, Kyoto Pref., Mt. Hiei NE of Kyoto, mixed forest, exhaustor, 3 males, 25.10.1995, leg. M. Jaschhof ( SDEI). Honshu Island, Miyagi Pref., Sendai, Mukaiyama, sweep-net, 1 male, 25.8.1998, leg. M. Sutou ( PMSY). Ryukyu Islands, Okinawa Pref., Iriomote Island, Funaura, broadleaved forest, exhaustor, 2 males, 5– 6.10.1995, leg. M. Jaschhof ( SDEI). Honshu Island, Tokyo, Hachioji, Yaentouge, sweep-net, 1 male, 20.7.1998, leg. M. Sutou ( PMSY).

Description. Male. Colour. Head, antenna, thorax and abdomen pale reddish brown, coxae paler brown, legs yellow. Wing fumose. Head. Eye bridge 3 facets wide. Face (prefrons) with 3–6 setae. Clypeus with 1 seta. Maxillary palpus, Fig. 1 A: with 3 palpomeres. Palpomere 1 with 1 seta, the hyaline sensilla in patch or shallow sensory pit. Palpomere 2 with 6 setae, palpomere 3 with 5 setae. Antennal flagellomere 4, Fig. 1 B, body 1.8–2.9 times as long as wide. Thorax. Anterior pronotum with 3–4 setae. Episternum 1 with 3–7 setae. Wings Length 0.9–1.4 mm, width/length 0.40–0.50. R1/R 0.45–0.80. c/ w 0.70 –0.85. r-m as long as bM or shorter, r-m/bM 0.60–1.00, r-m and bM non-setose. Anal lobe weak. Legs. Apex of fore tibia, Fig. 1 C. Length of fore basitarsomere/length of fore tibia 0.45–0.60. Abdomen. Sternite 8 with 4–11 setae. Hypopygium ( Fig. 1 D–F). Tegmen with gently curved sub-basal lateral shoulders. Aedeagal apodeme rather long, aedeagal teeth ca. 10. Gonocoxite as long as gonostylus, sparsely setose. Gonostylus narrow, with one large curved megaseta on a large basal body at about the basal third of the gonostylus, with one stout apical and one smaller subapical megaseta. No apical tooth.

Female. Unknown.

Discussion. In the large material studied, there is variation in the structure of the gonostylus and in the length of the antennal flagellomeres of Keilbachia acumina . However, we consider the specimens conspecific. K. acumina is very similar to K. subferrata Rudzinski , but is distinguished by having the smaller mesial megaseta in a more apical position, the large megaseta in a more basal position and by having the basal body of the latter shorter. K. acumina also resembles K. ferrata Hippa & Vilkamaa by having a rather long subbasal mesial megaseta on a large basal body and one apical and one subapical megaseta on the gonostylus. K. acumina can be distinguished by having the basal body slightly smaller, and by having the socket of the apical megaseta more distinct, and by having its tegmen more roundish laterally, with no distinct basolateral shoulders.

Figures

FIGURE 1. Keilbachia acumina sp. n. (A paratype from Higashi-ichiki, B paratype from Iriomote, C paratype from Mt. Aso, E and D holotype, F paratype from Tsurugizaki). Maxillary palpus (A) in lateral view, antennal flagellomere 4 (B) in lateral view, apex of front tibia (C) in prolateral view, part of hypopygium (D), gonostylus (E) and apex of gonostylus (F) in ventral view. Scale for B 0.05 mm, for others 0.10 mm.