Platypygus ridibundus (Costa)

Gharali, Babak, Evenhuis, Neal L. & Almeida, Jorge, 2013, World synopsis of described species of the genus Platypygus Loew (Diptera: Mythicomyiidae: Platypyginae), Zootaxa 3745 (2), pp. 199-242 : 225-226

Platypygus ridibundus (Costa)

( Figs. 16–18 )

Popsia ridibunda Costa, 1863: 52 . Loew, 1873: 206. Pagano, 1901: 270. Bezzi, 1924: 3. Paramonov, 1939: 28. François, 1966: 158. Hall, 1975: 3. Evenhuis, 1991: 63. El Hawagry, 2011: 138.

Platypygus ridibundus (Costa) . Becker et al., 1903: 192. Kertész, 1909: 97. Verrall, 1909: 14. Bezzi, 1926: 259. Paramonov, 1926: 87; 1929: 205; 1934: 16. Engel, 1933: 126. François, 1966: 157. Hennig, 1969: 59, 61; 1972: 16. Zaitzev, 1969: 558; 1989: 45. Mühlenberg, 1971: 20. Hull, 1973: 262. Evenhuis, 1983: 487; 2002: 26. Theodor, 1983: 33. Nagatomi et al., 1991: 596. Contini et al., 1995: 6. Hasbenli &Aktaş, 1995: 150. Carles-Tolrá & Báez, 2002: 108. Papp, 2003: 316; 2004: 137. Koçak & Kemal, 2009: 49.

Platypygus tauricus Paramonov, 1926: 88 . Engel, 1933: 126. Paramonov, 1934: 16. Liepa, 1969: 19. Hull, 1973: 262. Evenhuis, 1983: 490; 2002: 26. Zaitzev, 1989: 45.

Material examined. Types: UKRAINE: 1 lectotype male and 5 paralectotype females, / Krym, Karadag, 20. VI. 25, Paramonov l. / Platypygus tauricus ♂♀ / Zool. Mus. Berlin (ZMHB). Non-types: BULGARIA: 1 female, Rozen b. Melnik, 20 May 1981, U. Göllner (ZMHB). CROATIA: 1 male, 3 females, Omblatal, near Gruz, 21 May 1934, E. Lindner, (SMNS). CYPRUS: 2 females, Peri [Pera] Pedi, 13 June 1971, G.A. Mavromoustakis (BMNH); 1 male, 1 female, Kalavassos [Kalavasos] dam, 165 m, 24 April 2002, B. Merz, J. Deeming, M. Ebejer, P. Gatt (MHNG). GREECE: 1 male, 5 females, Fokis, Giona Oros, 2 km N. Sikea, 8 Jun 1982, R. Danielsson (MZLU); 2 males, 3 females, Corfu, Parga-Gaastouri, 10 May 1980, I.F.G. McLean; 2 males, 2 females, Corfu, Dassia, 30 April–6 May 1972, A.E. Stubbs (BMNH). PORTUGAL: 4 females, 1 male, Serra do Caramulo, Caramulinho, near Viseu, 30 June 2010, J. Almeida (J. Almeida); 5 males, 5 females, same data except, 11 July 2010, J. Almeida; 1 female, same data except 23 June 2011; 1 female, same data except 12 July 2010; 7 males, 7 females, Fonte Paulo Luís Martins, 30 June 2010, J. Almeida (all in BPBM). TURKEY: 3 males, 4 females, Antalya, Phaselis, 10 km S Kemer, 27 April 2000, Merz & Senay (MHNG); 1 female, Iznik, 3 km s. near Iznik Lake, 9 May 1991, B. Mocek (M. Barták); 3 females, Büyükiceli, Rt 400, 50 km SW Silifke, 12 May 2000, A. Freidberg, H. Ackerman, L. Freidman ( TAU).

Notes on types. Platypygus ridibundus was originally described by Costa (1863) (as “ Popsia ridibunda ”) based on an unknown number of specimens from Calabria, Italy. If the types survive, they would be in MZUN. We have not been able to track down the status of the original type series.

Platypygus tauricus was originally described by Paramonov (1926) based on 41 male and female specimens from “Krym” in the Ukraine, all collected by S.J. Paramonov on 20 June 1925. Paramonov said “ Typus in Meiner Sammlung” but there is no single specimen that could be singled out as the intended holotype so, following Evenhuis (2002) they are considered here as syntypes. Forty of these syntypes were located by Evenhuis (2002): 37 syntypes in ZMHB and 3 syntypes in SIZK. Six of these syntypes in ZMHB were examined in this study. The best preserved of these is here designated as lectotype male ( Fig. 16 a) and carries the following labels: “Krym / Karadag / 20.VI.25 / Paramonov. l.” [handwritten], “ Syntypus ” [printed on red card], “Zool. Mus. / Berlin” [printed], “ Typus Platypygus / tauricus ♂♀ ” [handwritten].

Diagnostic features. Face yellow; frons yellow with Y-shaped black mark ( Fig. 16 b); postgena without posterior extension; occiput black ( Fig. 16 c); pronotum with a dark orange mark dorsomedially; mesonotum yellowish white with three longitudinal orange stripes, with moderately dense black hairs; scutellum yellowish white with black hairs; lateral margin of mesonotum yellowish white; spot next to transverse suture absent ( Fig. 16 c); pleura yellowish white, usually without black mark ( Fig. 16 c), although in some specimens lower pleura can appear grey to black; halter yellowish white; crossvein r-m at middle of cell dm (16d); legs yellowish white except two last tarsal segments blackish; abdomen yellowish with short scattered black hairs.

Male genitalia ( Fig. 17 ). In dorsal view epandrium semicircular, acutely narrowed apically, cerci triangular, not well sclerotized ( Fig. 17 b), gonocoxites triangular, fused, with two long hyaline sclerites medially; gonostyli fused to gonocoxites, greatly sclerotized apically and concave with two small denticles ( Fig. 17 a); epiphallus conical, tapering to tip, aedeagal bulb large, basal aedeagal apodemes narrow, length about two times that of lateral apodeme ( Fig. 17 c), apically with three short denticles ( Fig. 17 d); lateral apodemes rectangular.

Female genitalia ( Fig. 18) (description based on a dissected specimen from Croatia). Furca U-shaped, lateral arms thin, sclerotized, connecting bridge weakly sclerotized; common oviduct very short; each spermathecal duct divided into two sections, a striated and broad basal duct, and a narrow, long, thin apical duct; without distinct sperm pump or valves; basal portion of median spermathecal duct narrower than that of lateral ducts, twisted spirally in median section; apical portion of duct narrower than basal portion, very long, 3.5 times basal portion; width of lateral spermathecal ducts about 2.5 times that of median duct; basal section of lateral spermathecal duct subequal to apical section; spermathecal reservoirs obconical, about 2 times longer than greatest width, sclerotized with a small rounded apical cap without canaliculi.

Theodor (1983) illustrated the female genitalia of a specimen he identified as Platypygus ridibundus . In his figure (page 33, figure 62), the vaginal furca is composed of two separate rods, which is different from the general U-shaped pattern found in the other species of the genus. Dissection of three female specimens of P. ridibundus from Portugal showed that the shape of furca is indeed U-shaped ( Fig. 18) and the apex of each lateral arm is bifurcate. A check of the actual slide upon which Theodor used for his illustration showed that it was based upon a misidentified specimen from Israel. There are no P. ridibundus in Israel and the species appears not to occur south of Turkey (over 3, 0 0 0 specimens of Mythicomyiidae from Israel, Syria, Egypt, Jordan, and the Arabian Peninsula have been seen by NLE and none are P. ridibundus ). Close examination of Theodor’s slide shows that the furca is indeed U-shaped but the portion connecting the two lateral arms [which are not bifurcate at the apex] is difficult to discern from surrounding tissue and was no doubt missed because of this. It is unknown what species Theodor illustrated as there are no associating numbers or labels between slides and pinned adults and Theodor dissected numerous individuals of Platypygus although only a few were illustrated. One adult in TAU is labeled in pencil by Theodor as “ ridibundus ” but it is not the dissected specimen and it appears instead to be a greasy specimen of P. chrysanthemi .

Zaitzev (1966) also illustrated the female genitalia, but only the spermathecal reservoir. It is somewhat similar in appearance to the one drawn by Theodor (1983) but lacks the canaliculi apically. We dissected specimens from Portugal ( Fig. 18), Croatia, and Turkey and the shape of the spermathecal reservoirs and apical caps differ from those drawn in Theodor (1983) and Zaitzev (1966). Assuming Zaitzev’s specimens were correctly identified, it could be that the shape of the spermathecal reservoir varies in P. ridibundus , or that this variation in spermathecal reservoir shape represents a complex of species that have a very similar external morphology.

Distribution. This species has a fairly wide but scattered distribution in the Old World occurring in the western parts of Europe (e.g. Portugal [new record], Spain), the southern and eastern parts of Europe ( Bulgaria, Croatia, Cyprus [new record], Greece (mainland and islands), Italy, Romania, Gruzia, Crimean Russia, Turkey, Ukraine), and extending toward Middle Asia (e. g. Azerbaijan, Armenia). Although Zaitzev (1989) implied a continuous range from Spain to Bulgaria and southern Russia in Europe and into northern Africa ( Egypt), many of these records were apparently based on misidentifications and there are actually very few verified records. Greathead & Evenhuis (2004) listed only the following verified countries in Europe based on examination of verified identifications of specimens: Croatia, Greece, Italy, Russia (south), and Spain. We can here confirm the records of Turkey (see Hasbenli & Aktaş 1995), Romania (Papp, 2004) and Bulgaria that are additional to those in Greathead & Evenhuis (2004) and here add the following new country records in Europe and Asia: Cyprus and Portugal. The Egyptian records, as with many others in the Mediterranean Region, were possibly specimens of Cyrtisiopsis melleus (Loew) [a very commonly occurring and, because of its generally yellowish to orangish color, a somewhat similar looking species] that were misidentified as P. ridibundus .

Remarks. Although Loew (1873: 206) mentioned in his note under Platypygus bellus that Popsia ridibundus was similar in body shape to his Platypygus bellus , he did not explicitly synonymize Popsia under Platypygus . Bezzi (1898: 36) was the first to do so.

Numerous specimens of this species were collected in Portugal by Jorge Almeida for the first time. Specimens were collected in Serra da Estrela, near Covão D’Ametade on Sedum spp. ( Crassulaceae ) flowers and in Serra do Caramulo, in Caramulinho on the flowers of Spergularia spp. ( Caryophyllaceae ) ( Figs. 19 b, c and e). This finding extends the distribution westward in the Iberian Peninsula.

An interesting finding in the specimens from Portugal is that the two lateral spermathecal reservoirs were atrophied and the apical ducts were aborted and did not end in any reservoirs ( Fig. 18). This situation is unique in the Platypygus species we have dissected. Reasons for this unusual character state in the specimens we dissected are unknown but could represent a genetic anomaly for that population or a variable set of characters for P. ridibundus .

Figures

FIGURE 16. Platypygus ridibundus: a — male lectotype of P. tauricus Paramonov (lateral view), b — specimen from Portugal (dorsolateral view of head), c — specimen from Portugal (lateral view), d — wing, e — unlaid egg.

FIGURE 17. Male genitalia of Platypygus ridibundus: a—gonocoxites (dorsal view), b—epandrium (dorsal view), c—phallic complex (dorsal view), d— (dorsal view), e—base of phallic complex (lateral view). Scales are the same for figures a-e.

FIGURE 19. Platypygus adults in field: a — Type locality of Platypygus titanomedea in northern Iran (Ghazvin), b, c — hovering activity of Platypygus ridibundus, d — fielf of flowering Gypsophila bicolor, e — Platypygus ridibundus on the flower of Spergularia cf. purpurea (Caryophyllaceae), f — Platypygus titanomedea on the flower of G. bicolor.