Empis (Xanthempis) montsegurensis, Langlois & Daugeron, 2024

Langlois, Dominique & Daugeron, Christophe, 2024, Two new species of the genus Empis Linnaeus, 1758 (Diptera, Empididae, Empidinae) from French nature reserves, Zoosystema 46 (13), pp. 319-325 : 322-323

Empis (Xanthempis) montsegurensis n. sp.

( Fig. 2 )

urn:lsid:zoobank.org:act:AEE7D705-F046-4877-B160-E215A6FA0835

TYPE MATERIAL. — Holotype. France • ♂; France , Montségur (09211), Réserve naturelle régionale du massif de Saint-Barthélémy, Caramille; 42°49’44”N, 1°47’41”E; 1745 m a.s.l.; 26.VI.2019; L. Servière; Malaise trap no. 4, wet meadow, near a pine and acidophilous beech forest; MNHN-ED-ED10936.

ETYMOLOGY. — Named after Montségur, the locality where the species was collected.

DIAGNOSIS. — A species of medium size belonging to the subgenus Xanthempis with the occiput dusted blackish dorsally to yellowish ventrally, a dusted greyish to blackish scutum except around postpronotal lobe and postalar callus. Hypandrium bare, phallus characteriscally sinuous at middle.

DISTRIBUTION. — France: Pyrenees ( Fig. 3 ).

DESCRIPTION

Male

Head. Ocellar triangle dusted blackish with pair of rather strong setae, occiput dusted blackish dorsally, yellowish ventrally, with strong, short setae. Frons brownish with setulae along the margin of eyes. Face, gena yellowish. Labrum yellowish, twice head height, labium brownish. Palpus yellowish with a few black hairs. Scape and pedicel brownish, postpedicel blackish; scape and postpedicel long, three and six times pedicel length respectively, style very short. Eyes dichoptic, all ommatidia of equal size.

Thorax. Antepronotum yellowish to blackish at middle, bilobed with 5-6 short spine-like setae. Postpronotum yellow with one anterior and one apical distinct setae, the latter stronger and longer. Prosternum, proepisternum yellow with 1-2 minute black hairs. Scutum dusted greyish to blackish, but yellowish around postpronotal lobe, postalar callus, notopleural area. Acrostichals absent, dorsocentrals uniserial, distinct, becoming strong, long in presculettar depression. Strong, long following setae: one postpronotal, one presutural supraalar, one notopleural, one postalar. Scutellum dusted greyish, with one pair of strong, long apical setae. Lateral parts of thorax yellow, laterotergite with a few strong, long setae. Postscutellum blackish to yellowish laterally. Anterior and posterior spiracles yellow.

Wing. Length: 6.5 mm. Rather clear feebly tinted of brown, veins brown, well sclerotized except anal vein feebly sclerotized basally but complete; anal lobe obtuse. Haltere slightly brownish. Stigma brownish not well visible.

Abdomen. Yellow with dorsal stripe formed by brown T-shaped spots on each tergite in dorsal view, another brownish stripe on each side along margin of tergites. Thin, short yellowish hairs or black thin, short setae at margin of tergite and sternite. Posterior margins of tergites 6 and 7 with a few strong, long and black dorsal setae, posterior margins of tergite and sternite 8 with many strong, long and black setae. Tergite and sternite 8 fused.

Hypopygium. Entirely yellow. Cercus higher than wide, lengthened ventrally, with dense rather thin, short and black dorsal setae, epandrium subrectangular, pointed apically, with strong and long dorsal setae subapically and apically, hypandrium reduced, bare, phallus long, curved, characteristically sinuous at middle.

Female

Unknown.

REMARKS

E. (X.) montsegurensis n. sp. can be easily distinguished from all other species of Xanthempis . For the moment it is known from a single specimen collected in the Pyrenees, and in addition to E. (X.) hypandrialis Daugeron, 2000 , E. (X.) montivaga Daugeron, 2000 , E. (X.) fagina Daugeron, 2009 , and E. (X.) virgulata Daugeron, 2009 , E. (X.) montsegurensis n. sp. is the fifth species of Xanthempis only known from the Pyrenees. The key proposed previously by Daugeron (2009) for species known from the mountain area is here modified to include the new species.

KEY TO SPECIES OF EMPIS (XANTHEMPIS) KNOWN FROM THE PYRENEES

1. Scutum entirely yellow ................................................................................................................................ 2

— Scutum with a blackish pattern ................................................................................................................... 3

2. Scape and pedicel brownish, occiput with a blackish-brown spot, hypandrium with pair of short apical spines, phallus pointed at tip ( Daugeron 2000: fig. 6) ......................................... E. (X.) montivaga Daugeron, 2000

— Scape and pedicel yellowish, occiput with pair of subrectangular blackish spots ( Daugeron 2009: fig. 3A), hypandrium with two pairs of short apical spines, phallus truncate at tip ( Daugeron 2009: fig. 1) ..................... ........................................................................................................................ E. (X.) fagina Daugeron, 2009

3. Scutum with at least one more or less broad central black stripe between dorsocentrals, epandrial lamella sub-triangular .................................................................................................................................................... 4

— Scutum entirely blackish, epandrium subrectangular ( Chvála 1994: fig. 301) .............................................. 6

4. Scutum with a broad central black stripe ..................................................................................................... 5

— Scutum with a single narrow central black stripe ( Chvála 1994: fig. 284) ........... E. (X.) stercorea Linné, 1761

5. Scutum yellow between dorsocentrals and notopleuron, hypandrium lengthened with many apical and subapical spines ( Daugeron 2000: figs 2; 3) ...................................................... E. (X.) hypandrialis Daugeron, 2000

— Scutum with pair of brownish to black spots, sometimes entirely fused in a single stripe, between dorsocentrals and notopleuron ( Daugeron 2009: fig. 3B), hypandrium not lengthened, bearing a single pair of subapical spines ( Daugeron 2009: fig. 2) ................................................................... E. (X.) virgulata Daugeron, 2009

6. Large species (wing length> 7 mm), abdomen usually entirely yellow, without stripe, two notopleurals, phallus regularly curved .............................................................................................. E. (X.) testacea Fabricius, 1805

— Smaller species (wing = 6.5 mm), abdomen yellow with a well visible dorsal stripe, one notopleural, phallus somewhat sinuous at middle ............................................................................... E. (X.) montsegurensis n. sp.

Figures

FIG. 2. — Empis (Xanthempis) montsegurensis n. sp.: A, male habitus;B, male hypopygium.Abbreviations:see Material and methods.Scale bars:A,1 mm;B, 0.2 mm.

FIG. 3. — Map of France showing the distribution of Empis (Empis) cartusiana n. sp. (●) and Empis (Xanthempis) montsegurensis n. sp. (Ω). Background map: Sémhur, Wikimedia Commons.