Ablabesmyia (Karelia) perexilis, Niitsuma, Hiromi, 2013

Niitsuma, Hiromi, 2013, Revision of the Japanese Ablabesmyia (Diptera: Chironomidae: Tanypodinae), with descriptions of three new species, Zootaxa 3664 (4), pp. 479-504 : 501-502

Ablabesmyia (Karelia) perexilis sp. n.

( Figs 67–69 )

Ablabesmyia longistyla: Sasa et al. 1998: 125 partim. [nec Fittkau, 1962]

Type material. Holotype male (SUM-IC-T0484), JAPAN: Gif, Mino, Suhara, Nagara River, 12.ix.2009 (adult emerged 20.ix.2009). Paratype. Kochi, Nakamura, 1 male (NSMT), labelled, “ Ablabesmyia longistyla No. 358: 49”, 26.iv.1998.

Etymology. From Latin perexilis , slender, referring to the long and narrow lateral lobe in the aedeagal complex.

Description. Male (n = 2). Body length 3.1–3.8 mm.

Colouration. Thorax yellow with dark brown scutal vittae, anepisternum II, preepisternum and postnotum. Abdomen pale yellow with dark markings; tergites III–V each with anterolateral markings, tergites VI–VIII mostly dark brown; hypopygium pale yellow. Wing ( Fig. 67 ) darkened on humeral cross-vein, RM, FCu, apex of R4+5, and areas along C between apices of R1 and R3, and above RM; distal marking in anal cell with basal extension. Subbasal and median bands on foretibia located 0.78–0.80 and 0.41–0.42, respectively, from apex of tibia.

Head. Temporals 24–34, multiserial except uniserial postorbitals. AR 1.6–1.7. Clypeus rounded with 35–39 setae. Lengths of palpomeres 1–5 (μm): 50–65, 100–120, 165–190, 190–215, 303–335. Pm4 1.1–1.2 times as long as Pm3; Pm5 1.6 times as long as Pm4.

Thorax. Aps 9–11; Ac 54–73, biserial between median scutal vittae, diverging posteriorly; Dc 23–24, uniserial, becoming biserial anteriorly; H 10–15; Pa 24–30; Su 1; Scts 72–85.

Wing. Length 2.1–2.5 mm. Squama with 48 (1) setae. VR 0.83.

Legs. Spur on foretibia 45–50 μm long, with 10 (1) lateral teeth. Spurs on mid tibia 53–55 and 33–38 μm long, with 7–8 and 5 lateral teeth, respectively; inner spur 1.5–1.6 times as long as outer spur. Spurs on hind tibia 55–70 and 33–38 μm long, with 6 (1) and 5 (1) lateral teeth, respectively; inner spur 1.7–1.9 times as long as outer spur; hind tibial comb consisting of 4–5 bristles. All legs with subapical pseudospurs on ta1–3; claws pointed or slightly bifid apically, each with 2 long and 3 short basoventral spines. Lengths and proportions of leg segments as in Table 7 .

Hypopygium ( Fig. 68 ). Tergite IX with 2 lateral setae. Gonocoxite 130–150 μm long; dorsal lobe 20 μm long, with setal fringe along almost full length; blade 38–43 μm long, curved with apex pointed; lateral lobe 45–53 μm long, slender, tapering and thinning toward membranous apex; lateral filaments not evident ( Fig. 69 ). Gonostylus 153–168 μm long, 1.1–1.2 times as long as gonocoxite, with apically acute megaseta.

Female, pupa and larva. Unknown.

Remarks. The males of A. (K.) perexilis are similar to those of A. (K.) makarchenkoi and A. (K.) lata in having a prominent lateral lobe in the aedeagal complex. However, the species are easily separable from them. The lateral lobe is slender in the former, while broad and stout in the latter two species.

Figures

FIGURES 67 – 69. Ablabesmyia (Karelia) perexilis sp. n., male. 67, Wing; 68, hypopygium, dorsal view; 69, aedeagal complex, dorsal view.