Keilbachia megacantha, 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 : 15-16

Keilbachia megacantha sp. n.

( Fig.10 A–D)

Type locality: JAPAN: Ryukyu Islands, Okinawa Pref., Iriomote Island, Ohara.

Material examined: Holotype male. JAPAN: Ryukyu Islands, Okinawa Pref., Iriomote Island, Ohara, broad-leaved forest, exhaustor, 4.10.1995, leg. M. Jaschhof ( SDEI).

Description. Male. Colour. Almost unicolorous pale brown, maxillary palpus and legs yellow, wings fumose. Head. Eye bridge 3 facets wide. Face (prefrons) with 5 setae. Clypeus with 1 seta. Maxillary palpus with 2 palpomeres. Palpomere 1 with 1 seta, the hyaline sensilla in patch on the dorsal surface, no sensory pit. Palpomere 2 smaller than palpomere 1, with 3 setae. Antenna long, flagellomere 4, Fig. 10 A, body 3 times as long as wide, flagellomeral necks long and narrow, setae longer than width of flagellomeral bodies. Thorax. Anterior pronotum with 2 setae. Episternum 1 with 5 setae. Wings. Length 1.2 mm, width/length 0.4. R1/R 0.60. c/ w 0.70. r-m and bM of about equal length, non-setose. Anal lobe weak. Legs. Apex of fore tibia, Fig. 10 B. Length of fore basitarsomere/length of fore tibia 0.60. Tibial spurs about as long as apical width of tibiae. Abdomen. Setae of sternite 8 with 6 setae. Hypopygium ( Fig. 10 C, D). Tegmen as long as broad, apically roundish, with small sharp lateral shoulders. Aedeagal apodeme moderately long, ca. 15 aedeagal teeth. Gonocoxite slightly longer than gonostylus. Gonostylus mesially impressed, with one subapical, oblique, strong mesial megaseta on a very large basal body. No other megasetae, and no apical tooth.

Female. Unknown.

Discussion. Keilbachia megacantha is similar to K. praedicata Rudzinski by having a large, oblique megaseta placed at the apical half of the gonostylus, and by lacking other megasetae or an apical tooth. K. praedicata has the basal body of the gonostylar megaseta smaller, whereby the megaseta does not extend as far basad as in K. megacantha ( Figs 10 and 12 ). Furthermore, the antennal flagellomeres of K. praedicata are relatively much longer, whereas in K. megacantha they are shorter but have longer necks and setae. For other species with the mesial megaseta in a relatively apical position, see under K. adjuncta .

Figures

FIGURE 10. Keilbachia megacantha sp. n. (holotype). Antennal flagellomere 4 (A) in lateral view, apex of front tibia (B) in prolateral view, part of hypopygium (C) and gonostylus (D) in ventral view. Scale for A 0.05 mm, for others 0.10 mm.

FIGURE 12. Keilbachia praedicata Rudzinski (from Taiwan). Antennal flagellomere 4 (A) in ventral view, part of hypopygium (B) and gonostylus (C) in ventral view. Scale for A 0.05 mm, for B and C 0.10 mm.