Egle steini Schnabl, 1911

Michelsen, Verner, 2009, Revision of the willow catkin flies, genus Egle Robineau-Desvoidy (Diptera: Anthomyiidae), in Europe and neighbouring areas, Zootaxa 2043 (1), pp. 1-76 : 37-39

10. Egle steini Schnabl in Schnabl & Dziedzicki, 1911

Figs. 103–108 , 180, 181 .

Egle steini Schnabl in Schnabl & Dziedzicki, 1911: 105, plate figs. 249, 250, 780; Ackland 1970: 188, 191, figs. 2, 7, 9,

12; Hennig 1976: 937, 938; Draber-Moṅko 1991: 234; Dely-Draskovits 1993: 52; Chandler 1998: 166; Petersen

2001: 184; Michelsen 2004. ‘ Hylemyia parva (Robineau-Desvoidy) ’; Ringdahl 1930: 5 (in part). Misidentification. Hylemyia ? steini (Schnabl) ; Ringdahl 1930: 5. ‘ Egle parvaeformis Schnabl’; Suh & Kwon 1985: 186, fig. 10 (1–6). Misidentification. Egle polychaeta Griffiths, 2003: 2331 , figs. 2631–2635. Syn. nov. For further references, see Griffiths (2003).

Taxonomic notes. The present species is unmistakable by the bugle-shaped distiphallus. Griffiths (2003) suggested that Egle steini is replaced by the vicariant E. polychaeta Griffiths in North America differing in some details of the male sternite V and pregonite. A direct comparison of Canadian and European males has convinced me that they belong to the same species. Accordingly, E. steini is here maintained as a Holarctic species.

Description. As for E. parvaeformis except: Slightly smaller, wing length 2.9–3.8mm.

Male. Notopleuron without accessory setulae. Proepisternals 1(–2). Submedian tibial setae: fore tibia with 1–3 pd- and 0–1 p-setae, all long and fine; mid tibia with 2–3 long and fine pd-setae. Sternite V ( Figs. 103, 104 ) strikingly large, also diagnostic in respect to setation and shape of posterior lobes; setal tufts posterolaterally on basal plate large, consisting of more that 20 setae and setulae. Terminalia ( Figs. 105–108 ): shape of cerci, surstyli and distiphallus diagnostic.

Female. Notopleuron without accessory setulae. Proepisternals 1; proepimerals 1–4. Hind femur on basal half with 1–2 very short and fine pv-setae. Oviscapt ( Figs. 180, 181 ): Tergite VI narrow and parallel-sided, no wider than long, spiracles VI and VII both situated far from its lateral margins. Sternites VI and VII extensively membranized on more than posterior halves. Epiproct complete, with 2–4 apical setulae; hypoproct deeply excavated basally, with 4–6 marginal setulae. Two spermathecae strikingly large and elongate, with cross-striae and very long ducts; third spermatheca and duct absent.

Material examined. BRITISH ISLES [ OUMNH]: Cambridgeshire: Chippenham Fen, 1 male 20.iii.1920, 1 male 23.iii.1945 (J.E. Collin). CZECH REPUBLIC [ ZMUC]: Central Bohemia: Praha-Hája, damp meadow + wood, 250m, 1 male 1.v.1991 (M. Barták); Libřické údolí, 250m, nr. brook, 1 female 23.iv.1983 (M. Barták); Nová Rabynĕ, 280m, meadow nr. river, 1 female 27.iv.1988 (M. Barták). DENMARK [ ZMUC]: NE Zealand: Utterslev Mose, 1 female 11.v.1981, 1 female 28.iv.1999, 3 females 28.iv.2008 ( V. Michelsen). NORWAY [ ZMUC]: Troms (outer): Tromsø, 1 female 25.v.1923 ( T. Soot-Ryen). FINLAND [ FMNH, ZMUC]: Nylandia: Helsinki , 1 male ( R. Frey), 1 male 18.v.1946 (L. Tiensuu). Karelia australis: Hamina , 1 male 29.v.1974 (L. Tiensuu); Vehkalahti , 7 males 7.v.1972, 1 male 17.v.1974, 2 males 13.v.1976 (L. Tiensuu). Ostrobottnia australis: Alavus , 3 males 14.v.1940, 1 male 17.v.1940 (L. Tiensuu). Karelia borealis: Hammaslahti , 1 male, 14.v.1928 (P. Kontkanen). RUSSIA [ FMNH]: St. Petersburg oblast: Pogra at river Svir , 1 male 16.v.1942 (L. Tiensuu). SWEDEN [ MZUL]: Skåne: Skanör , 1 female 5.v.1955 (P. Ardö). Torne Lappmark : Abisko , 1 male, 1 female 18.vi.1951 (J. R. Vockeroth). Nearctic specimens seen from CANADA [ ZMUC]: New Brunswick: Kouchibouguac Nat. Pk., 1 male 18.v.1977 (B. Cooper); Ontario: Ottawa , 1 male 14.v.1943 (A. Brooks) .

Biology. In Alberta ( Canada) reared from catkins of Salix planifolia Pursh according to Griffiths (2003). Other species of willow are certainly suitable as host plants, at least in the Palaearctic Region.

Distribution. A Holarctic species. Widespread in the boreal to low arctic zones of North America as summarized by Griffiths (2003) for the synonymous E. polychaeta Griffiths. Also from Korea (Suh & Kwon 1985), but misidentified as E. parvaeformis . According to my notes, Ringdahl’s (1930) record of ‘ Hylemyia ? Steini Schnabl’ from Kamchatka based on 1 male is correct, but also 1 male and 2 females recorded under ‘ Hylemyia parva R.D.’ represent the present species. In Europe, it is known from British Isles ( Ackland 1970), Denmark ( Petersen 2001), Poland ( Schnabl & Dziedzicki 1911) and from the Czech Republic, Finland, Norway, Sweden and NW Russia ( Michelsen 2004). Records from Germany ( Teschner 1999; Michelsen 2004) are based on a misidentification.

Figures

FIGURES 103–108. Egle steini, male terminalia. 103, 104. Sternite V, ventral and lateral views. 105, 106. Hypopygium, caudal and lateral views. 107. Pre- and postgonites, lateral view. 108. Phallus, lateral view. Same scale.

FIGURES 180–183. Egle spp., female terminalia. 180. E. steini, oviscapt, flat mounted. 181. Same, spermathecae. 182.?E. ignobilis, oviscapt, flat mounted [Norway]. 183. Same, spermathecae. Different scales.