Description of the male of Euthycera seguyi Vala, 1990 (Diptera, Sciomyzidae)

Orsis, 8: 73-77 (I 993) Description of the male of Euthycera seguyi Vala, 1990 (Diptera, Sciomyzidae) Miguel Carles-Tolrhl and Jean-Claude Vala2 1. Avda. Principe Asturias 30 ático la, 08012 Barcelona, Spain 2. Université d'Avignon, Laboratoire de Biologie Animale, 33, me Louis Pasteur, 84000 Avignon, France Key words: Allotype male, diptera, distribution, Euthycera seguyi, Sciomyzidae. Abstract. The male of Euthycera seguyi Vala, 1990 (Diptera, Sciomyzidae) is described and illustrated for the first time. The distribution of this species, limited originally to the type-locality in France is extended to Spain. A key of west-palearctic species of Euthycera is established. Resumen. Descripción del macho de Euthycera seguyi Vala, I990 (Diptera Sciomyzidae). Se captura y describe por primera vez el macho de Euthycera seguyi Vala. La distribución de dicha especie se amplia a España. Por último, se da una clave de las especies paleártico-occidentales de Euthycera. Introduction In 1990, Vala described a new species of Sciomyzidae, Euthycera seguyi, from a single female collected in France at Le Vernet near Perpignan (Pyrénées Orientales) in 1904. The female holotype was discovered in the Diptera collection of the INRA Versailles. A few months later, the first author received a male specimen of Euthycera collected by Mr. Garanto in north-eastern Spain. After a detailed study we came to the conclusion that it belongs to Euthycera seguyi. In fact, it shows all of the most distinctive characters of the species, a typical general pattern and the absence of acrostichal presutural and prescutellar bristles in particular. We present the description of the male of Euthycera seguyi and illustrate the male genitalia for the first time. The examined specimen is here designated as the allotype of the species under study. Euthycera seguyi Vala. Male (Figures 1-8) Head. Face concave, with a whitish pruinosity, without any darkening in middle. Large lunula, shiny grey-brown, strongly exposed, with depression in middle, and protuberant between antennae. Mid-frontal stripe brown, subshining, large, and concave mid-frontal stripe, almost reaching anterior margin of frons. Orbito-antennal spot between lunula and eye margin pale brown, not very visible. On each orbital plate, 2 pairs of fronto-orbital bristles, bases of bristles are linked together by a long velvety brown orbital spot. Each orbital spot edged on anterior (ocular side) and posterior half (ocellar triangular side) with silvery pruinosity. Orbital plates mat yellow, with a few fine and short hairs on anterior margin. Convex ocellar triangle with 2 strong ocellar bristles. 1 pair of inner and outer verticals. Very strong postocellar bristles. Cheeks with a few fine black hairs extending along lateral margin of face. Some stronger and longer hairs on occiput. Antennae brownish; first segment minute, yellow-brown, with a row of bristles on anterior margin; second segment subshining, with many short bristles, particularly on anterior margin; third segment subequal to second segment, mat, yellowish around base of arista. Arista with brown basal segments, rest of arista with short and white plumosity. Thorax. Greyish, with 4 distinct longitudinal dark stripes on mesonotum: 2 continuous linear submedian, 2 lateral ones cut by the transverse suture. On each side of mesonotum, chaetotaxy consisting of 1 humeral, 2 notopleural, 1 supraalar, 2 postalar and 2 dorsocentral bristles. Scutellum with a large brown longitudinal stripe and 2 pairs of scutellar bristles. Legs. Pale yellow except for 115 apical part of fore tibia and the 3 last fore tarsal segments being black. Tarsal segments of other legs more or less whitish, nevertheless 2-3 first segments darkened by dense short hairs. Fore femur with 5 strong anterodorsal bristles and another 1 in middle of upper posterior side. Middle femur with 1 strong anterior bristle in middle. Hind femur with 2 ventrolateral rows of strong bristles. Preapical bristles well developed on all tibiae. Abdomen. Yellowish brown, strongly marked with whitish pruinosity; dorsal side distinctly darker; longitudinal brown mark present on each abdominal segment. Periandrium brownish. Male genitalia (Figs. 1-8): synsternite (Fig. 2) and sternite V (Fig. 3) equiped with large sclerotized parts; gonostylus (= posterior surstylus) with solid base and convex externa1 edge (Figs. 1, 4, 5, 6). Anterior cornua of hypandrium in shape of a claw with very outspread halves (Fig. 7) and with large sclerotized plate between them. Body length 6.6 mm, wing length 5 mm. Material examined Allotype male: Spain, Tarragona, Aiguamúrcia, 13-20.XI. 1988 (Garanto leg.), collected with a vinegar trap. Additional female: Spain, Barcelona, Begas, 28.1X.1982 (Carles-Tolrh leg.), collected on grass in a burned pinewood. All material is deposited in the private collection of Dr. Carles-Tolrh. EUTHYCERA SEGUYI, MALE 75 Figures 1-8. Euthycera seguyi allotype male. 1, periandrium in caudal view. 2, synsternite 6-7. 3, sternite V. 4, gonostylus in caudal view. 5, ibid. in anterior view. 6, ibid. in lateral view. 7, aedeagal complex, ejaculatory apodeme and hypandrium in anterior view. 8, aedeagal complex in posterior view. aed= aedeagus; aej= ejaculatory canal apodeme; ant hyp= anterior arm of hypandrium; cer= cercus; gon= gonostylus; hyp= hypandrium; par= paramere (= postgonite); peri= periandrium. Scales equal to 0.2 mm. 76 M. CARLES-TOLRA & J.-C. VALA Discussion Regarding Vala's description of Euthycera seguyi female (1990), we found only a few externa1 morphological differences between both sexes: the right anterior dorsocentral bristle is present, no hairs on the prosternum are distinct and the orbito-antennal spot is barely visible in the male. As regard the male postabdomen, the particular morphology of synsternite 6-7 (sternum 6), hypandrium and aedeagal complex are clearly different from those of the other Euthycera species. Among 17 species of the genus Euthycera, Euthycera seguyi is the ninth species recorded in Spain: Rozkosny (1987), Vala (1989) and Carles-Tolrh (1990). The previously cited species are E. alaris Vala, 1983, E. chaerophylli (Fabricius, 1798), E. cribrata (Rondani, 1868), E. fumigata (Scopoli, 1763), E. stichospila (Czerny, 1909), E. stictica (Fabricius, 1805), E. vockerothi Rozkosny, 1988 -described exclusively from Spain-, and E. zelleri (Loew, 1847). In addition to these species, we can cite E. guanchica (Frey, 1936), endemic species of Canary Islands. The species is recently known in the west-mediterranean area with 1 site in south-western France and 2 sites in north-eastern Spain (Fig. 9). Geographically all these sites are situated in the same Catalonian area. Figure 9. Euthycera seguyi, distribution map. EUTHYCERA SEGUYI, MALE 77 Key to the west-mediterranean species of Euthycera 1. Arista long black plumose, yellowish species .................... chaerophylli (Fabricius) - Arista short white haired ..................................................... 2 2. Face with a black spot in the middle ................................... 3 - Face without black spot ....................................................... 4 3. Mesonotum without acrostichal presutural bristles, femora bicolorous, dark brown with a broad yellow ring in apical half at least on middle and hind femora ..................................... vockerothi Rozkosny - Mesonotum with complete chaetotaxy, femora unicolorous stictica (Fabricius) 4. Mid-frontal stripe flat and mat, antenna dark brown to blac. cribrata (Rondani) - Mid-frontal stripe concave and shining ............................... 5 5. Anterior wing margin mainly dark brown without pale spots, legs yellow .......................................................................... fumigata (Scopoli) - Anterior wing margin with pale spots ................................. 6 6. Mesonotum without presutural and acrostichal presutural brisseguyi Vala tles ........................................................................................ - Mesonotum with complete chaetotaxy ................................ 7 7. Wings with pale spots concentrated into distinct groups ...... alaris Vala - Wings with pale spots not concentrated into groups ........... 8 8. Body dark brown, central area of wings around anterior cross-vein not distinctly paler ............................................. stichospila (Czerny) - Body yellow-brown, central area of wings around anterior cross-vein distinctly paler ................................................... zelleri (Loew) Acknowledgements We want to thank very much Mr. Oscar Garanto (Mida, Les Borges Blanques) for the loan of his dipterological material for study. We are also most grateful to Dr. R. Rozkosny of Bmo (Czechoslovakia) for corrections and cornments on the original manuscript. References Carles-Tolrh, M. 1990. Contribución al estudio de 10s Diptera, Cyclorrhapha, Acalyptratae (Insecta) de España peninsular. Tesis Doctoral. Facultad de Biologia. Barcelona. 621 pp. Rozkosny, R. 1987. A review of the palaearctic Sciomyzidae (Diptera). Folia Fac. Sci. Natur. Univ. Purkyn. Brun., Biol., 86: 1-99 + 56 pls. Rozkosny, R. 1988. New records of Sciomyzidae (Diptera) from Spain, including the description of a new species of Euthycera Latreille. Acta ent. bohemoslov., 85: 457-463. Vala, J.-C. 1989. Diptkres Sciomyzidae euro-méditerranéens. Faune de France 72, 302 p. 9 pl. Vala, J.-C. 1990. Une nouvelle espbce d'Euthycera Latreille récoltée en France (Diptera: Sciomyzidae). Annals Soc. ent. Fr. (N.S.), 26(3): 451-455. Manuscript received on Aprill992