Dioctria vainsteini Lehr

Young, Charles L. & Hradský, Milan M., 2008, Robber flies (Diptera: Asilidae) of South Korea. Parts VI – VIII. South Korean species of the Subfamilies Dasypogoninae, Dioctriinae and Trigonomiminae, Zootaxa 1876, pp. 1-18 : 10

Dioctria vainsteini Lehr

( Figs 11–16 )

Dioctria vainsteini Lehr, 1999: 626 .

Small sized dark, slender delicate flies, 7–8.5 mm. Dioctria vainsteini is distinguished from the other species of the genus Dioctria from South Korea by the 1st antennal segment which less than 2 times as long as segment 2, and by the distinct basally dark tinged wings.

Adult. Male.

Head. Upper face shining black, extending medially to mystax; laterally with bright gold tomentum. Mystax semicircular in shape, with sparse long yellow hair. Relative lengths of antennal segments: 3 + 4<1<2. 1st antennal segment less than 2 times as long as long as segment 2. Thorax dull black with fine yellow micropubescence. Stripe of yellow/gold tomentum on pleurae complete, running ventrally up from anterior margin of katepisternum, dorsally and laterally along anepisternal margins, terminating on posterior margin of katepisternum. Postpronotum dark yellow, black medially. Median and paramedian stripes of scutum well defined, yellow micropubescence. Scutum wrinkled. Chaetotaxy with: 1 presutural; 2 supraalar bristles. Postalar yellow laterally. Scutellum broadly wrinkled with sparse fine yellow marginal hair. Legs yellow and black with fine white hair and yellow bristles. Fore, mid and hind femora yellow; fore, mid and hind tibiae yellow, black laterally. Hind tibia apically swollen with sharp apical spurs. Tarsomeres black. Wing clearly tinged black on basal half, distal half clear. Abdomen: Black with diffused yellow apical bands. Tergites 2–4 with faint yellow lateroapical patches; tergite 5 with basal lateral yellow patch; tergites 4, 5 with apical yellow dorsal bands. Male genitalia ( Figs 11–16 ) dark orange/tan with long yellow hair. Gonopod ( Figs12–14 ) slender; gonostylus lobate. Aedeagus ( Figs 15, 16 ) stout, truncated with 2 slender endoaedeagi.

Female. Similar to male. Tergite markings less prominent. Cerci prominent with stiff yellow hair.

Variation. The yellow of the postpronotum (humeral callus) and postalar may be bright to barely visible.

Material examined. Kangwon Province. 1ɗ,Ψ: 11/VII /– 7/VIII/2004, Chuncheon Nam-Myon, Magon-Li, Hongcheon River, 37° 43’ 78”N, 127° 34’ 58E.

Kyongsangnam Province. 1ɗ: 5–15/VIII/2003, Macheon, Chiri Mt. 750m., 35°20’55”N, 127°38’21’’E.

Field notes. All specimens were collected in Malaise traps using 95% ethanol. No recorded prey. See also the table on prey and seasonality.

Figures

FIGURE 11 – 16. Dioctria vainsteini, male genitalia. 11, lateral; 12, ventral; 13, gonopod, ventral; 14, gonopod, dorsal; 15, aedeagus, dorsal; 16, aedeagus, lateral.