Colocasiomyia longivalva Li & Gao, 2014

Li, Nan-Nan, Toda, Masanori J., Fu, Zhao, Chen, Ji-Min, Li, Su-Hua & Gao, Jian-Jun, 2014, Taxonomy of the Colocasiomyia gigantea species group (Diptera, Drosophilidae), with descriptions of four new species from Yunnan, China, ZooKeys 406, pp. 41-64 : 49-51

Colocasiomyia longivalva Li & Gao sp. n.

Figs 6 , 13 , 20 , 29-36

Type material.

Holotype ♂ (No. 000079): CHINA: Baihualing, Longyang, Baoshan, Yunnan, 1500 m (25°17.19'N, 98°47.65'E), ex Rhaphidophora decursiva inflorescence at Stage III, 17.vi.2011, JJ Gao (KIZ).

Paratypes: same data as holotype but 16.vi.2011 (2♂, 8♀: Nos 000080-87, 171, 172); same but 15.vi.2011 (1♂: No. 000170) (KIZ, SEHU).

Description.

Adult male. Head: Supracervical setae 13 per side. Dorsomedial arm of tentorial apodeme 1/3 as long as dorsolateral arm. Eye red, somewhat roundish, with very sparse interfacetal setulae. Frontal vitta mat, black. First flagellomere not concave on inner margin. Facial carina trapeziform, medially wider than twice width of first flagellomere, as long as pedicel and first flagellomere combined. Palpus convex on ventrodistal portion. Cibarial posterior sensilla minute, 1 per side ( Fig. 29 ). Labellum with 20 pseudotracheae per side.

Thorax: Scutum and scutellum glossy, black; thoracic pleura glossy, blackish brown. Acrostichal setulae in 6 rows.

Wing: Veins yellow. Halter grayish brown except for grayish yellow stalk.

Legs: Foreleg second tarsomere with 8-10 pegs ( Figs 6 , 13 ). Foreleg coxa large, with approximately 8 long setae on underside near attachment to trochanter. Small preapical dorsal setae present only on tibiae of hindlegs.

Abdomen: Tergites glossy, entirely dark brown; II to VI+VII each bearing setulae and setae irregularly arranged; setae of posteriormost row largest. Sternites grayish yellow; VI posteriorly not bilobed.

Terminalia ( Figs 30-35 ): Epandrium notched above insertion of ventral lobe, pubescent except for anterolateral margin to ventral portion and ventral lobe, with 7-8 setae per side along ventral margin of ventral lobe and approximately 10 setae (including 2 thickest ones located just above and 2 shortest ones just on subventral notch) along posterior margin; anteroventral portion curved inward, apically articulated to lateral arm of hypandrium ( Figs 30 , 31 ); ventral lobe prolonged like rod, apically with grooved, finger-like peg ( Figs 30-32 ). Surstylus basally articulated to inner, basal corner of epandrial ventral lobe, 1/3 as long as epandrial ventral lobe, distally nearly parallel with epandrial ventral lobe, with 2 trichoid setae apically and 2 trichoid, thinner setae on ventral, subapical surface ( Figs 31 , 33 ). Cercus large, somewhat rhombic, wider than 1/2 its (dorsoventral) height, pubescent on dorsal 2/3, with approximately 33 setae mostly distributed near posterior margin, including slightly prominent one at caudoventral apex ( Fig. 30 ). Membrane between epandrium and cercus pubescent dorsally to laterally. Tenth sternite folded into two lateral lobes connected with each other caudodorsally; lateral lobe triangularly extended anterodorsally, fused with membrane between epandrium and cercus. Hypandrium narrow plate-like, posteriorly T-shaped, with lateral arms fused to membranous, aedeagal basal processes ( Figs 34 , 35 ). Parameres long, coalescent to hypandrium, triangular in ventral view, apically with 4 minute sensilla arranged in a row, basally fused to each other ( Figs 34 , 35 ). Aedeagus nearly entirely separated into a pair of lateral lobes, pubescent basally, bent ventrad subapically, narrowly pointed at apex; aedeagal apodeme rod-like, 1/2 as long as aedeagus ( Fig. 34 ); aedeagal basal processes membranous, connecting dorsobasal corners of aedeagus and lateral arms of hypandrium.

Measurements (holotype / range in 3♂ paratypes, in mm): BL = 3.30 / 2.40-3.20, ThL = 1.40 / 1.18-1.42, WL = 2.80 / 2.50-2.88, WW =1.09 / 1.03-1.20.

Indices (holotype / range in 3♂ paratypes): FW/HW = 0.49 / 0.48-0.50, ch/o = 0.51 / 0.53-0.54, prorb = 1.04 / 1.25-1.49, rcorb = 0.44 / 0.44-0.50, orbito = 0.74 / 0.56-0.66, vb = 0.47 / 0.38-0.50, dcl = 0.50 / 0.51-0.59, presctl = 0.50 / 0.51-0.59, sctl = 0.91 / 0.65-0.77, sterno = 0.65 / 0.56-0.66, mid katepisternal seta indistinguishable from other fine setae, dcp = 1.08 / 0.86-1.07, sctlp = 1.23 / 1.10-1.26, C = 1.76 / 1.79-1.83, 4c = 1.16 / 1.18-1.19, 4v = 1.83 / 1.85-1.95, 5x = 0.98 / 0.99-1.18, ac = 4.54 / 3.84-4.08, M = 0.14 / 0.15-0.17, C3F = 0.83 / 0.84-0.88.

Female. Head, thorax, wing and legs as in male.

Terminalia: Tergite VII mid-dorsally not constricted; VIII pubescent nearly entirely, with 3-4 setae in a transverse row on unpubescent medio-posterior portion. Oviscapt distal narrow portion twice as long as proximal, broad portion, with approximately 18, 6 and 3 trichoid ovisensilla per side on ventral, dorsal and apical margins, respectively, and tiny, peg-like ovisensillum near mid-dorsal margin ( Fig. 36 ).

Measurements (range in 8♀ paratypes, in mm): BL = 2.80-3.21 (7♀), ThL = 1.26-1.47, WL = 2.67-2.90, WW =1.08-1.26.

Indices (range in 8♀ paratypes): FW/HW = 0.49-0.52, ch/o = 0.49-0.54, prorb = 0.97-1.25, rcorb = 0.34-0.57, orbito = 0.56-0.73, vb = 0.43-0.64, dcl = 0.49-0.56, presctl = 0.49-0.56, sctl = 0.64-0.87 (7♀), sterno = 0.63-0.87, dcp = 0.82-1.06, sctlp = 1.10-1.31, C = 1.78-2.06, 4c = 1.05-1.23, 4v = 1.81-1.99, 5x = 0.88-1.18, ac = 3.55-4.36, M = 0.14-0.18, C3F = 0.84-0.89.

Distribution.

China (Yunnan).

Etymology.

Pertaining to the long oviscapt valva.

Remarks.

Adults of this species were very rarely captured from inflorescences of Rhaphidophora decursiva . So far we have never get any adult of this species by laboratory rearing from the host inflorescences/infructescences. This species is distinguished from the other members of the gigantea group: epandrium somewhat notched above insertion of ventral lobe; epandrial ventral lobe prolonged like rod, apically with grooved, finger-like peg ( Figs 30-32 ); surstylus 1/3 as long as epandrial ventral lobe, distally nearly parallel with the latter ( Figs 31 , 33 ); paramere large, as long as hypandrium ( Figs 34 , 35 ); distal narrow portion of oviscapt twice as long as proximal, broad portion ( Fig. 36 ).

Figures

Figures 2 - 22. SEM photographs showing leg and oviscapt fine structures in the Colocasiomyia gigantea species group. Foreleg tarsomeres I and II (2 - 8), pegs on foreleg tarsomere II (9 - 15) and warts on basal part of lateral lobe or basal membrane of oviscapt (16 - 22) of Colocasiomyia gigantea (2, 9, 16), Colocasiomyia scindapsae (3, 10, 17), Colocasiomyia rhaphidophorae (4, 11, 18), Colocasiomyia longifilamentata sp. n. (5, 12, 19), Colocasiomyia longivalva sp. n. (6, 13, 20), Colocasiomyia hailini sp. n. (7, 14, 21) and Colocasiomyia yini sp. n. (8, 15, 22). Scale line = 0.1 mm in 2 - 8, 0.05 mm in 9 - 15. Figures 16 - 22 are in the same magnification, with the width corresponding to 30 µm.

Figures 29 - 36. Colocasiomyia longivalva Li & Gao, sp. n. Adult male and female (paratypes) from Baihualing, Yunnan, China: 29 Cibarium and clypeus (dorsal view) 30 periphallic organs (posterolateral view) 31 periphallic organs (ventral view) 32 apical part of epandrial ventral lobe (ventral view) 33 surstylus (ventral view) 34 phallic organs (lateral view) 35 hypandrium and parameres (ventral view) 36 oviscapt (lateral view). Scale lines = 0.1 mm.