Ptecticus guangxiensis, Zai-Hua, Yang, Xiao-Ming, Chen & Mao-Fa, Yang, 2015

Zai-Hua, Yang, Xiao-Ming, Chen & Mao-Fa, Yang, 2015, Two new species and two new records of Ptecticus Loew (Diptera: Stratiomyidae: Sargiinae) from China, Zootaxa 3964 (4), pp. 433-444 : 436-438

2. Ptecticus guangxiensis sp.nov.

( Figs 6–12 )

Diagnosis. A species from the australis group with a black frons, an ochre yellow thorax, a hyaline postcubital vein (CuP) and a transversely striped abdomen. The male terminalia are different from all other species in this group.

Description. Body length 7.2–11.5 mm, wing length 7.2–12.0 mm.

Head with upper frons, vertex and occiput shining black, upper frons densely punctate, with sparse yellow hairs, hairs on vertex and occiput black, longer than those on upper frons. Ocellar triangle relatively narrow, placed far from posterior head margin. Eyes almost touching above frontal callus, frons at narrowest point much narrower than anterior ocellus. Frontal callus nose-shaped, snow white, sometimes with dark lateral spots. Face yellowish white, sometimes with darker parts. Antenna ochre yellow, arista dark brown. Proboscis yellow. Posterior margin of eyes bordered by erect brown hairs becoming paler ventrally.

Thorax yellow and shining, slightly darker yellow and finely punctate on scutum, scutum with longitudinal though inconspicuous stripes, finely punctate, with sparse yellow short hairs. Scutellum yellow as scutum. Pleura completely shining yellow, without any dark pattern, with sparse yellow pubescence. Wing ( Fig. 6 ) hyaline, usually longer than abdomen, with a slight brownish yellow tinge, veins and stigma yellowish brown. R2+3 arising proximal to anterior crossvein, slightly longer than R4, anterior crossvein relatively strong, M3 not touching wing margin (its apical 1/4–1/6 missing). Halter dark brown, with yellowish base. Posterior crossvein absent. Legs mostly yellow, but two apical tarsomeres on fore and mid legs darkened, hind tibia dark brown to black. Fore and mid basitarsus almost as long as tibia. Hind femur slightly darker than the fore and mid femur. Hind tibia and basal 1/5 of hind basitarsus dark brown, rest of hind tarsus snow white. Pubescence on legs predominantly short and dense, golden yellow but brownish yellow on mid femur and tibia, and black on hind tibia and basal part of hind basitarsus. White parts of hind tarsus with white pubescence.

Abdomen ( Fig. 7 ) shining black with yellow transverse bands. Black part with bronze to purplish metallic sheen. Tergite 1 with (sometimes without) narrow yellow distal margin. Nearly distal half (or less) of tergites 2–4 yellow, sometimes tergite 4 with very narrow yellow distal transverse band. Tergite 5 wholly black. Venter shining yellow, sternite 5 black. Abdominal pile yellowish white. Width of abdomen about 0.8 times as thorax. Male terminalia ( Figs11–12 ). Dorsal part simple, proctiger arched, with semicircular depression in lateral view. Width of genital capsule distinctly longer than its length, medial emargination of genital capsule with a pair of sharp, teethlike structures. Aedeagal complex bipartite, apical third of both parts gradually tapered and sharply pointed, scissors-like, about basal part of aedeagal complex unusually swollen.

Female. Body length 7.5–11.5 mm, wing length 7.2–12.0 mm. Very similar to male, except as follows: eyes distinctly separated by broad frons, frons at narrowest part about 0.08 times as head, with almost parallel lateral sides, upper frons shining black, frontal callus, face and proboscis white, without any dark part. Abdomen about 1.2 times as long as thorax, distinctly wider than in male. Tergite 5 with yellow parts at proximal margin and distal lateral corners. Cerci cylindrical, black with dark hairs, two-segmented, basal segment approximately 1.2 times as long as apical segment.

Specimens examined. Holotype ♂, 12.viii.2011, Neichao village (( 23°30’N, 108°27’E), 222–463m, Liangjiang town, Wuming, Guangxi Province, Zaihua Yang leg (GAFC). Paratypes: 21♂, 7♀, with same locality labels (GAFC).

Etymology. The species is named after the province where the holotype was collected.

Remarks. The new species is very similar to P. vulpianus but it can be distinguished by the frontal callus almost snow white, usually without brown to black patches, but occasionally they appear at lateral sides, but not in lower half. The hind femur completely yellow. The middle of the genital capsule with a pair of sharply pointed structures. The aedeagal complex bipartite, its apical 1/3 is scissors-like, basal part considrably swollen.

Distribution. China (Guangxi).

Figures

FIGURES 6 – 12. Ptecticus guangxiensis sp. nov., male: 6, wing; 7, abdomen in dorsal view; 8, epandrium, proctiger and cerci in dorsal view; 9, epandrium, proctiger and cerci in lateral view; 10, aedeagal complex in lateral view; 11, genital capsule and aedeagal complex in dorsal view; 12, genital capsule in ventral view.