Lonchoptera vaillanti, Zwick, 2004

Peter Zwick, 2004, Lonchoptera vaillanti sp. nov., a new fly from Switzerland (Diptera: Lonchopteridae), Mitteilungen Der Schweizerischen Entomologischen Gesellschaft 77, pp. 133-136 : 133-136

Lonchoptera vaillanti sp. nov.

( Figs 1-6 )

Material: Holotype ♂, paratype ♂, Switzerland, Ticino, Valle Mesolcina, Fiume Moesa at Buffalora Falls , 12 Aug. 2001, R Zwick . Specimens in 15% ethanol, some parts in Euparal on glass slides. Holotype in Musée de Zoologie, Lausanne; paratype in my collection.

A typical Lonchoptera , wing length 3.5-3.8 mm. Vein A ends in wing margin. No long seta at the end of R. Wing index 2.9, wing angles: 1, 155°; 2, 224°; 3, 135° (see Vaillant 1989). Most veins with tiny black setae.

Body brown, thorax more vividly ochre with 3 dark dorsal stripes; part of thoracic pleura also infuscate, ventral side of thorax and legs yellow. Setae dark except the moderately sized ones around the inner rear margin of the compound eyes and small setae on the rear face of the head. Wings ochre, veins brown.

Fore tarsus segments 3-5 modified, able to roll up tightly, ventrally with en­larged dark setae near medial edge as follows: segment 3 with a distal spatulate seta; segment 4 with 3 basal setae, the large outer ones spatulate, the smaller one between them pointed; segment 4 with a curved small dark seta at base ( Fig 1 ). Middle femur with a row of 6 ventral spines, the 3 posterior ones thick and curved. Middle tibia simple, unmodified, without anterodorsal seta. Hind leg unmodified.

Secondary male characters: Abdominal sternites 3 and 4 each with a pair of straight setae on either side, those on segment 4 very large, reaching over the anterior edge of the large genitalia which are folded forward against the abdominal venter. Tergite IX large, dish-shaped, dorsal face with sparse dark setae. Short flangelike cerci enclosing the indistict proctiger between them not well separated from tergite IX. Cerci strongly setose, ventrally with 3 enlarged sinuous setae on either side near edge ( Figs 2, 3 ). Sternite IX in the shape of a narrow transverse bar with indistinct anterior tip and a strongly socketed and strongly sinuous seta on either side, middle bare ( Figs 2, 3 ). Posterior gonapophyses short, with a pair of very unequal setae. The huge anterior one with double sinuosity, conspicuously narrowed to long pointed tip. The small posterior seta straight (note that the normally erect posterior gonapophyses and their setae are downfolded and therefore pointing mediad in the slide preparation shown in Figs 3, 4 !). All major setae distinctly fluted ( Fig 5 ). Anterior gonapophyses in the shape of two divergent transparent fingers, each with three tiny sensilla in a subterminal fold ( Fig 6 ). The base of the gonapophysis carries a large external hook ( Fig 4 ). Penial sclerites not studied in detail; the long phallapodeme visible by transparency ( Fig 4 ).

Female, pupa and larva: Unknown.

Affinities and distinction: L. vaillanti sp. nov. belongs to a group identified by the same general shape o f tergite IX, short, flange-like cerci, and short posterior gonapophyses with a pair of unequal setae. Among these species, L. vaillanti sp. nov. shares a row of spines on the middle femur with L. strobli (De Meijere) andC. nerana Vaillant. L. vaillanti sp. nov. shares with L. nerana the finger-shaped distal part of the posterior gonapophysis, with L. strobli the basolateral hooked portion. In the key to German species ( Bährmann & Bellstedt 1988) L. vaillanti sp. nov. keys to L. strobli but the setal pair on the anterior gonapophyses easily separates the related taxa. In L. strobli and L. nerana both setae are only slightly curved; they are of very unequal size in L. nerana , less so in L. strobli . The thickness and double sinuosity of the larger seta in L. vaillanti sp. nov. reminds a little bit of L. tristis Meigen, 1824 where, however, the sinuous part is contracted, knob like, and the thin tip reduced to a tiny spine so that the entire apex resembles a bird’s head (see figures in Vaillant 1992). However, L. tristis has simple middle femora and a curved and slightly swollen hind tibia ( Bährmann & Bellstedt 1988, their fig. 17). L. tristis and also L. pictipennis (Bezzi, 1899) have 4 setae on sternite IX. However, the development of the paramedian setae differs much between these two species.

Distribution and habitat: Geographically, L. vaillanti sp. nov. occurs in the Ticino, between its two closest relatives. L. strobli is found in the Alps but Vaillant (1989) emphasizes its absence from France, which is not far from where L. vaillanti sp. nov. was taken. The single known specimen of L. nerana comes from the spring shore of the Nera river in the Apenninian Mti Sibillini. L. vaillanti sp. nov. was picked at the waterline on a large rock in the torrential Fiume Moesa and was, at the time of collection, mistaken for some aquatic Empididae . The numerous specimens of L. strobli that served for comparison all came from an emergence trap on the stream Jägergraben at Lunz, Lower Austria. Adults of several additional Lonchoptera are regularly and in large numbers taken in emergence traps on streams, or swept from stream banks or hygropetric sites on rock faces, like L. tristis and L. fallax (De Meijere, 1906) (my own data). However, aquatic larval habitats are documented only for L. lutea Panzer, 1809 and L. nigrociliata (Duda, 1927) ( Vaillant 2002 ).

Dedication: It is my pleasure to respectfully name this species for Prof. François Vaillant, Grenoble, in recognition of his important contributions to the study of Lonchopteridae , and many other groups of mainly aquatic insects.

Figures

Figs 1 - 6. Lonchoptera vaillanti sp. nov., male. 2. male genitalia, dorsal view - 3. same, ventral view - 4. same, detail, scale is same as for fig 1. — 5. left anterior gonapophysis - 6. apex of left posterior gonapophysis - 1. ventral view of segments 2 - 5 of right fore tarsus. Figs 5 and 6 are not to scale. aG, anterior gonapophysis; C, cercus; P proctiger; pG, posterior gonapophysis; S 9, sternite IX; T 9, tergite IX.