Platypygus titanomedea Gharali & Evenhuis

Gharali, Babak, Evenhuis, Neal, Kamali, Karim & Talebi, Ali Asghar, 2011, A review of the genus Platypygus Loew (Mythicomyiidae: Platypyginae) in Iran, with notes on Cyrtisiopsis maculiventris (Loew) n. comb., Zootaxa 2979, pp. 25-40 : 27-30

Platypygus titanomedea Gharali & Evenhuis , sp. nov.

( Figs. 1 & 2 )

Diagnosis. Frons entirely yellow; scape and pedicel yellow; mesonotum covered with dense, fine, long, pale hairs, with three longitudinal black stripes and two black spots; male genitalia huge, well exposed; furca of female genitalia with two sclerotized plates next to genital orifice, spermathecal reservoirs acorn-shaped.

Specimens examined. 40 males and 40 females, Zereshk Pass, North of Ghazvin city, Ghazvin province, N 36°28'85", E 50°10'80", 1738 m asl., 24 June 2009, swept on Gypsophila bicolor , leg. B. Gharali; 2 males and 2 females, Marand, Payam region, N 38°20'15", E 45°46'59", 1914 m asl., 3 August 2009, sweeping, leg. B. Gharali.

Type depositories. Holotype female and 9 paratypes [4 males, 5 females], Zereshk pass ( TMUC); 16 paratypes [8 males 8 females] ( BPBM); 20 paratypes [10 males, 10 females], data same as holotype ( IRIPP); other paratypes (12 males, 12 females), data same as holotype, in personal collection of the first author.

Description. Holotype female. Length 2.8 mm.

Head ( Figs. 1 b & k). Subglobular, slightly longer than high; eyes dichoptic, separated at vertex by 1.7 x distance between lateral ocelli; occiput wide, 0.2 x eye width, yellow at lower third, remainder black, with long white hairs, hairs denser in upper part; postgena minutely extended posteriorly as blunt process; vertex black, with black color extends triangularly below median ocellus; ocellar triangle with scattered short white hairs; frons depressed medially as longitudinal furrow, yellow, with long white hairs laterally; antennal length ( Fig. 1 f) 0.5 x head height, basal two segments of antennae yellow, remainder black, antennal ratio: 1.2: 1: 2.1: 1.4; scape obconical, 1.5 x as long as widest part; pedicel subcylindrical, slightly longer than wide; first flagellomere oblong oval, length about 2 x greatest width; second flagellomere cylindrical, length 0.7 x that of first flagellomere, style bullet-shaped, length 0.3 x that of second flagellomere; face yellow, with scattered long and white hairs; oral margin very narrow, yellow; gena yellow, as narrow as oral margin; mentum yellow; labrum blackish, sclerotized, stiff, pointed apically; proboscis blackish, with fleshy wide labellum.

Thorax ( Figs. 1 c, 1h). Pronotum yellow with black mark medially; mesonotum yellow, with dense and white long hairs, with three longitudinal black stripes on disc and two black spots next to transverse suture; black stripes joined together by a transverse black band posteriorly; lateral stripes extend from posterior margin of postpronotal lobes to scutellum, median stripe from anterior margin of mesonotum to scutellum, postpronotal lobes large, yellow; postalar calli yellow; scutellum yellow with a triangular black mark basomedially, with long white hairs throughout; halter stem and knob yellow; pleura yellow except lower two thirds of katepisternum black and a large black basomedial spot on meron leaving anterior margin and upper part of meron yellow.

Legs. Completely yellow except last three tarsal segments faintly brownish; claws black; pulvilli white, as long as claws.

Wings ( Fig. 1 j). Hyaline, veins yellow at base, becoming brownish apically; costa ends slightly beyond R4+5; R2+3 originates from about the middle of Rs; R4+5 sinuous, ending in costa well beyond the level of M2; M1 curved, longer than M2; M2 straight; M3 straight, originates from middle of discal cell; CuA1 straight, reaching wing margin

2. P. k u rd o r u m Paramonov is usually found on the plant family Asteraceae (e.g., Anthemis sp.).

freely; humeral crossvein as long as crossvein r-m; crossvein m1-m2 shorter than crossvein r-m; crossvein m-cu as long as crossvein r-m; crossvein r-m slightly beyond the middle of discal cell; discal cell closed, length 2.7 x widest part; anal cell narrowly open, alula and alar squama reduced; fringe of hairs on posterior margin of wing shortest at wing tip becoming longer toward base.

Abdomen ( Fig. 1 e). Tergites predominantly black except posterior and lateral margins yellow with long white hairs; sternites completely yellow.

Female genitalia: ( Figs. 2 f, 2g). Furca U-shaped, sclerotized, much sclerotized in lateral arms; with two sclerotized plates next to vaginal opening; common spermathecal duct very short, brown, sclerotized; lateral spermathecal ducts about 2 x width of median duct; without distinct sperm pump or valves; each spermathecal duct divided into two sections, a basal section as a striated, long and broad tube, shortly sclerotized proximally, widening gradually toward tip and end as a small bulb, and an apical section as a narrow and smooth tube, 1/6 width of basal tube, 0.4 x length of basal tube; basal part of median spermathecal duct much narrower than that of lateral ducts, without striation, twisted spirally in median section, gradually broadened apically, expanded as a small bulb at the end; spermathecal reservoirs acorn-shaped with apically rounded caps, height of caps about 3/4 of basal part.

Male ( Fig. 1 a). Similar to female except the following:

Yellow color of tergites expanding anteriorly toward last tergites, so three last tergites are almost entirely yellow; hypopygium very large, prominent, yellow except epandrium brown posteriorly and its long processes blackish brown.

Male genitalia. ( Figs. 2 a–d). In lateral view epandrium trapezoid, height subequal to greatest width, with two long processes posteroventrally; cerci membranous, not evident, gonocoxites suboval, fused narrowly, medially with a pair of less sclerotized and clavate processes; gonostyli clavate, stem long, deeply inserted in gonocoxites, apically much sclerotized, hollowed; epiphallus conical; aedeagal bulb large, ventrally with two small triangular processes basally; basal aedeagal apodeme subquadrate with forwardly oriented rectangular and narrower plate in lateral view, length about 1.5 x that of lateral apodeme; lateral aedeagal apodemes subrectangular, length 2.3 x greatest width.

Remarks. Using Engel’s key (1933) to the species of Platypygus in the Palaearctic region, P. titanomedea runs to P. kurdorum , but both Engel’s (1933) and Paramonov’s (1929) keys included only a part of the Palaearctic species, so P. titanomedea is here compared with all related species. Adult males of the new species are easily distinguished from the related species by the huge and well exposed male genitalia, and females are separated from related species by the following characters, which are also applicable to males.

It is similar to Platypygus kurdorum Zaitzev, 1975 but is easily distinguished by the hairy mesonotum (bare in P. kurdorum ), the two yellow basal segments of antennae (completely black antennae in P. kurdorum ) and the presence of two sclerotized plates adjacent to the genital orifice in the female genitalia (without sclerotization around the genital orifice in P. kurdorum ). Platypygus titanomedea is also separated easily from P. lativentris by the yellow halter (with a black spot on the knob of the halter in P. lativentris ) and the yellow frons (with a wide black stripe in P. lativentris ). It is also distinguished from P. melinoproctus by the soft and pale hairs on the abdomen (bristly black hairs in P. melinoproctus ), and the two black spots behind the transverse suture (without black spots in P. melinoproctus ). Platypygus titanomedea is separated from P. chrysanthemi by the color of hairs on mesonotum. In the former species these hairs are completely pale but in the latter the hairs on mesonotum are completely black. The hairs on the mesonotum are moderately weak and may be matted by handling (especially on disc) so in dubious cases the lateral margin of the mesonotum and the other diagnostic characters (including antennal color, female genitalia) should be checked for correct identification of female specimens.

Variability. The black mark on the frons is somewhat variable and ranges from no mark to a narrow black stripe in the middle. The proboscis length is highly variable and ranges from shorter to much longer than head (the shortness could be due to retraction of the proboscis within the head capsule in some specimens). Also the end of the median black stripe on the mesonotum is sometimes narrowed, pointed, and separated from the posterior margin of the mesonotum.

Distribution. Currently known from northern Iran (Ghazvin, East Azerbaijan & Zanjan provinces) ( Fig. 10 ) but future examination of specimens that were misidentified as P. k u rd o r u m by Zaitzev (1966) may show a wider distribution for P. titanomedea including Middle Asia and the Caucasus regions.

Etymology. The specific epithet derives from the combination of two Latin words, titan = “large size” and medea = “genitalia” referring to very large and well exposed male genitalia in which the epandrium is much larger than the other parts and is easily seen without dissection.

Plant association. This species was frequently collected on the flowers of Gypsophila bicolor (Freyn & Sint.) Grossh., 1919 (Caryophyllaceae) ( Fig. 8 a, b), a common plant in the north of Iran, and is also widely distributed in Turkey, Transcaucasia, the Caucasus, Afghanistan, and Armenia, so P. titanomedea could potentially be found in these regions in association with this plant.

Figures

FIGURE 2. Genitalia of P. titanomedea: a—epandrium (lateral view), b—epandrium (posterior view), c—gonocoxa and gonostyli (dorsal view), d—phallic complex (lateral view), e—phallic complex (dorsal view), f—female genitalia except reservoirs, g—spermathecal reservoir.

FIGURE 8. Gypsophila bicolor: a—natural habitat of the plant, b— P. titanomedea on the flower of G. b i c o l o r.

FIGURE 10. Distribution map of Platypygus species in the Palaearctic region.

FIGURE 1. P. titanomedea: a—male, b—female, c—mesonotum (dorsal view), d—male abdomen (dorsal view), e—female abdomen (dorsal view), f—antenna, g—male abdomen (lateral view), h—mesonotum (lateral view), j—wing, k—head (anterodorsal view).