Dicranomyia (Dicranomyia) quadra ( Meigen, 1838 )

Starý, Jaroslav & Stubbs, Alan E., 2015, Five species under Dicranomyia (Dicranomyia) mitis (Meigen, 1830) (Diptera, Limoniidae), Zootaxa 3964 (3), pp. 321-334 : 329-330

Dicranomyia (Dicranomyia) quadra ( Meigen, 1838) , sp. restit.

Figs 3 , 8 , 13 , 18

Limnobia quadra Meigen 1838: 29 (description).

? Dicranomyia hygropetrica Vaillant 1952: 250 (description), Figs 11 (tarsal claw), 13–14 (male terminalia). Limnobia quadra: Morge 1976 , Plate 78, Fig. 6 (general view).

Species A: Stubbs 1998a: 23 (key), Fig. (wing, male terminalia).

Diagnosis. Medium-sized species. Body colouration ochreous to yellowish-brown, variegated with yellow. Wing pattern with only quadrangular pterostigma fairly distinct; other markings feebly indicated. Sc1 without any macrotrichia. Two last male tarsomeres long, parallel-sided; male tarsal claws with only one tooth fairly distinct. Male terminalia with rostral prolongation of ventral gonostylus truncate close beyond medial spine; rostral spines shorter than those of other species treated here, gently curved, separated at base by their own breadth. Female terminalia with cercus subequal in length to tergite 10; space between cerci very narrow, about one third width of cercus breadth at base. Wing length 6.5–9.5 mm.

Redescription. Male. Head with silvery grey pruinosity on frons and vertex, yellowish-brown at base, rostrum yellowish-brown. Antenna brown, reaching to about anterior margin of prescutum. Flagellomeres ovoid, with verticils slightly shorter than respective segments. Palpus dark brown.

Thorax generally ochreous to yellowish-brown. Pronotum ochreous, sometimes slightly darker posteromedially. Prescutum ochreous, with pale grey pruinosity, sometimes darker medially as well as on scutal lobes; scutellum and mediotergite yellowed anteriorly. Pleuron ochreous, slightly paler than dorsum of thorax. Wing with pterostigma moderately distinct, quadrangular; narrow, sometimes little-distinct seam along so-called outer cord (Fig. 18). Sc1 without any macrotrichia. Halter with knob infuscated. Legs generally yellow to yellowish-brown, tips of femora, tibiae and tarsal segments slightly darkened. Two last tarsomeres darker, rather long, subequal in length, straight, parallel-sided, rod-like, both with longitudinal row of stiff, short, suberect setae on distal half ventrally; setae indistinctly hooked at tip. Tarsal claws shorter than those in D. (D.) mitis and D. (D.) affinis , about one fourth length of tarsomere 5, with one well-developed tooth at one third length, other teeth littledistinct ( Fig. 3 ).

Abdomen brown dorsally, paler ventrally. Male terminalia ( Fig. 8 ): Tergite 9 distinctly shorter than in D. (D.) mitis and rather narrow, more than twice as broad as long, with shallow, rather U-shaped, median emargination at posterior margin and usually incomplete median suture. Gonocoxite enlarged laterally at base, comparatively short, distinctly less than half length of ventral gonostylus. The latter long-ovoid, about twice as long as broad. Rostral prolongation of ventral gonostylus truncate close beyond medial spine. Rostral spines shorter and broader than in other species treated here, gently curved, separated at base by their own breadth.

Female. Resembling male in general appearance, including structure of tarsi and tarsal claws. Female terminalia ( Fig. 13 ): Cercus gently upturned, subequal in length to tergite 10. Space between cerci very narrow, about one third width of cercus breadth at base. Genital fork (vaginal apodeme) triangular, extending to posterior margin of tergite 10. Sternum 9 short, about one third length of tergite 10.

Material examined (55 ♂, 25 ♀). Bulgaria: Kresna nr. Simitli, 30. v.1976, 1 ♂ (K. Majer leg.); Ostar Kamak, 6. v.1980, 2 ♂, 1 ♀ (W. Krzemiński leg.) (all JSO). Czech Republic: Bohemia: Šumava Mts, Horská Kvilda, Hamerský brook, 6. vii.1992, 1 ♂ (J. Starý leg., JSO). Moravia: Hrubý Jeseník Mts, Branná, “Dembauda”, 17. vii.1972, 1 ♂; Hrubý Jeseník Mts, Kouty nad Desnou, Divoká Desná valley, “Zámčisko” (970 m), 26. vi.2003, 3 ♂, 2 ♀, 21. vii.2003, 1 ♂, 1 ♀, 21. vii.2009, 1 ♂; Hrubý Jeseník Mts, Praděd, Bílá Opava valley (900–1000 m), 26. vii.1994, 1 ♂; Bedřichov nr. Oskava, 11. vi.1975, 1 ♂; Rešov, waterfall, 17. vi.1969, 1 ♀; Jívová nr. Olomouc, 27. vi.1969, 1 ♂, 14. vi.1978, 1 ♂; Hrubá Voda nr. Olomouc, 23. vi.1970, 1 ♂; Moravskoslezské Beskydy Mts, Tanečnice (900–1000 m), 18. vii.1985, 1 ♂, 2 ♀, 15. vi.1989, 1 ♂, 23. vi.1989, 1 ♂, 12. vii.1990, 1 ♂; Moravskoslezské Beskydy, “Malinová” (700–800 m), 27. vi.1991, 1 ♂, 17. vii.1991, 1 ♂, 24. vi.1993, 3 ♂; Moravskoslezské Beskydy Mts, Prostřední Bečva (500–600 m), 4. vi.1992, 1 ♂, 30. vii.1992, 1 ♀, 9. vi.1993, 2 ♂, 18. vi.1993, 3 ♂, 1 ♀, 23. vi.1993, 1 ♂, 2 ♀, 7. vi.1994, 1 ♂ (all J. Starý leg., all JSO). Great Britain: England: Westmorland, Loughrigg, 3. vi.1968, 1 ♂; Westmorland, Stock Ghyll, 3. vi.1968, 1 ♂, 3 ♀ (all A.M. Hutson leg., all BMNH)). Scotland: Kinlochewe, 4. vii.1953, 1 ♀; Kinlochewe, Ben Eighe, 11. vii.1953, 1 ♂, 1 ♀ (all O.W. Richards leg.); Eigg Isle (West Scotland), Cleadale, by stream, 28. v.1970, 6 ♂, 1 ♀ (A.M. Hutson leg.); Glenshiel, 30.VI.1934, 2 ♂ (O.W. Richards leg.); Balmoral Forest, 24.vi.–13. vii.1951, 1 ♂ (R.L. Coe leg.); Isle of Arran, Catacoul, 29.–30. v.1919, 2 ♂ (F.W. Edwards leg.); Glen Lyon, 14. vii.1955, 1 ♀ (L. Parmenter leg.) (all BMNH). Wales: Flint, Frith, 7.–9. vi.1919, 2 ♂, 1 ♀ (F.W. Edwards leg., BMNH). Greece: Region Pieria: Olympos Mts, Prionia (1000–1200 m), 1. vi.2007, 2 ♂, 6. vi.2007, 2 ♂, 4 ♀ (J. Starý leg., JSO). Italy: Sardinia: Monte Albo Mts, Siniscóla 5 km W, nr. Sant’Anna (maquis) (715 m), 40°35'N 9°38'E, 9. v.2014, 1 ♀; Monte Albo Mts, Simiscóla 4.3 km W (brook) (570 m), 40°35'N 9°39'E, 9. v.2014, 1 ♀ (all J. Starý leg., all JSO). Slovakia: Zuberec env., 23. vi.1998, 1 ♂; Vysoké Tatry Mts, Nové Štrbské pleso, 22. vii.1969, 1 ♂; Belianske Tatry Mts, Skalné Vratá, 24. vii.1969, 1 ♂ (all J. Starý leg., all JSO).

Discussion. By its size and general body colouration D. (D.) quadra somewhat resembles pale specimens of D. (D.) mitis , but it lacks setae on Sc1. Male tarsal claws are shorter than those in D. (D.) mitis and D. (D.) affinis , about one fourth the length of tarsomere 5 ( Fig. 3 ). Male terminalia of D. (D.) quadra show traits not seen in the other species treated here: tergite 9 proportionally small; gonocoxite comparatively short and broad, distinctly less than half the length of the ventral gonostylus, enlarged laterally at base; rostral spines shorter than in the other species ( Fig. 8 ). Female terminalia have the space between cerci very narrow, about one third the width of cercus breadth at base, which is not the case for the other species treated here ( Fig. 13 ).

Ecology. In Great Britain, this is a northern and western species though locally present in more southerly parts. It can occur in abundance by woodland streams and modest-sized rivers, including ravines. It can be found in company with D. (D.) lutea and D. (D.) imbecilla . The flight season can extend from June to August ( AS).

Distribution. The species is here recorded for Bulgaria, Czech Republic, Great Britain, Greece, Italy (Sardinia), and Slovakia; other country records are Germany (probable type locality of quadra , see Meigen 1838) and possibly Algeria (type locality of hygropetrica , see Vaillant 1952). Probably widespread throughout Europe.

Figures

FIGURES 1 – 5. T wo distal tarsomeres and tarsal claw (with details of tarsal claw). 1 — D. (D.) mitis (Czech Republic: Bohemia: Šumava Mts). 2 — D. (D.) affinis (Morocco: Rif Mts). 3 — D. (D.) quadra (Czech Republic: Moravia: Hrubý Jeseník Mts). 4 — D. (D.) lutea (Czech Republic: Moravia: Moravskoslezské Beskydy Mts). 5 — D. (D.) imbecilla (Czech Republic: Moravia: Hrubý Jeseník Mts). Scale bar 0.25 mm.

FIGURES 6 – 10. Male terminalia, general view, dorsal (with details of rostral prologation of ventral gonostylus). 6 — D. (D.) mitis (Czech Republic: Bohemia: Šumava Mts). 7 — D. (D.) affinis (Morocco: Rif Mts). 8 — D. (D.) quadra (Czech Republic: Moravia: Hrubý Jeseník Mts). 9 — D. (D.) lutea (Czech Republic: Moravia: Moravskoslezské Beskydy Mts). 10 — D. (D.) imbecilla (Czech Republic: Moravia: Hrubý Jeseník Mts). Scale bar 0.5 mm.

FIGURES 11 – 15. Female terminalia, internal structures, ventral. 11 — D. (D.) mitis (Czech Republic: Moravia: Moravskoslezské Beskydy Mts). 12 — D. (D.) affinis (Morocco: Rif Mts). 13 — D. (D.) quadra (Czech Republic: Moravia: Hrubý Jeseník Mts). 14 — D. (D.) lutea (Czech Republic: Moravia: Moravskoslezské Beskydy Mts). 15 — D. (D.) imbecilla (Czech Republic: Moravia: Hrubý Jeseník Mts). Scale bar 0.5 mm. ce—cerci; gf—genital fork (vaginal apodeme); ifp—infraanal plate; s 9 — sternum 9; t 10 — tergite 10.