Leptocera fontinalis

Leptocera fontinalis (Fallén, 1826)

(Figs. 28, 157–162, 206–209)

Copromyza fontinalis Fallén, 1826: 16 (lectotype ♀, NHRS, not examined).

Leptocera fontinalis.— Roháček, 1982: 13 (redescription); Roháček et al., 2001: 153 (World catalog).

Limosina arcuata Macquart, 1835: 572 (?MNHN,? types lost, tentative synonymy, see Roháček, 1982: 19).

Taxonomy. Most, if not all, previous records of this species from the Nearctic (and certainly all records from the Neotropical region) are based on misidentifications (see Introduction), namely of L. caenosa and L. erythrocera, and to a lesser degree L. neofinalis sp.n. and L. kanata sp.n. In fact, most literature citations refer to localities outside the fairly small range of L. fontinalis established here (e.g., Johnson & Coquillett, 1895; Howard, 1900; Tucker, 1907; Johnson, 1913; Malloch, 1914, Sanders & Shelford, 1922; Spuler, 1924; Bird, 1930; Usinger & Kellen, 1955; Judd, 1957; Kilpatrick & Schoof, 1957; Walker, 1957; Reed, 1958; Frost, 1964; Richards, 1967; Gapasin & Kim, 1972; Johnson, 1975; Samšinák, 1989).

Description. A detailed redescription of the species was provided by Roháček (1982). Outstanding paramedian acrostichals strongly enlarged, longest one at least 0.8x as long (usually as long) as lower orbital bristle; prescutellar acrostichals also slightly to moderately enlarged. Mid tibia with bristle above distal dorsal clearly longer than (up to twice as long as) anteroapical bristles; posteroapical bristles subequal and short (shorter than in any other species), not reaching socket of ventrobasal metatarsal bristle (Fig. 28).

Male terminalia (Figs. 157–159): Sternite 5 with posteromedial desclerotized area relatively large, bearing unusually numerous pale bristles (see Roháček, 1982: Fig. 18). Anterior section of surstylus with anterior process in lateral view moderately long and relatively wide apically; ventral lobe rounded and prominent, with long bristles. Apex of anterior process without prominent, bare, darker, lateral ridge (ventral view). Posterior section of surstylus with bristles restricted to basal half, very numerous; the two strong apical bristles more or less unequal. Aedeagal complex as in Figs. 206–209.

Female terminalia: Hind margin of sternite 7 straight, median 2/5 with edge narrowly bare (devoid of microtrichia), well sclerotized and usually slightly darker; sternite therefore appearing sharp-edged in undissected specimens (in other species except L. neovomerata sp.n. hind margin gradually desclerotized, evenly microtrichose and therefore ill-defined). Sternite 8 with lateral margins sinuate, posterolateral lobes well developed, subtriangular, rounded apically; median process rounded and wide. Spermathecae subcylindrical, spicules more numerous in apical half, often absent near base; apex with well-developed invagination, base laterally with similar depression (in paired spermathecae located on side facing other spermatheca); surface with very fine striation.

Material examined. CANADA. Newfoundland: 8 ♂♂, 3 ♀♀, St. John’s, Agric. Exp. Stn., various dates, 14–30.vii.1967, J.F. McAlpine (CNCI); 1 ♂, Portugal Cove, 11.vii.1987, garden sweep, T.A. Wheeler (DEBU); 2 ♂♂, Squires Mem. Pk. [= Sir Richard Squires Memorial Prov. Pk.], 12.vi. and 24.vii.1961, C.P. Alexander (USNM). Nova Scotia: 1 ♂, 3 ♀♀, Jordan Falls, 9.viii.1958, J.R. Vockeroth (CNCI); 2 ♀♀, Mount Uniacke, 5.viii.1958, J.R. Vockeroth (CNCI); 1 ♀, Lockeport, 4.viii.1958, J.R. Vockeroth (CNCI); 2 ♀♀, Kentville, 10 and 13.vii. 1924, R.P. Gorham (CNCI); 1 ♀, Antigonish Co., 1 km N Antigonish, 26.v–2.vii.1984, FIT, L. MacMillan (DEBU); 1 ♀, Cape Breton Highlands Natl. Pk., Lone Shielding, PG731861, 11.vii.1983, maple forest, malaise, A. Borkent (DEBU); 2 ♂♂, Halifax, vii.1967 and 8.vii.1971, N.L.H. Krauss (USNM). Quebec: 2 ♂♂, Beaulieu [probably: Sainte-Pétronille], Cottage Beaulieu, 7.vi. and 7.vii.1906. U.S.A. New Hampshire: 1 ♀, Rockingham Co., 1 mi SW Durham, 12–26.v.1967, FIT, D.S. Chandler (DEBU). We have also examined numerous specimens from the following European countries: Austria, Czech Republic, France, Germany, Italy, Spain, Sweden and Switzerland (DEBU, CNCI, TAMU).

Distribution (Map 10). Eastern Canada (NF, QC, NS) and northeastern U.S. (NH); western and central Palaearctic region: all of Europe, including Iceland (towards south mostly in mountains), North Africa (Tunisia), and central Asia (Uzbekistan, Tajikistan, Afghanistan) (Roháček et al., 2001). The distribution pattern of L. fontinalis strongly suggests that it was introduced to North America, probably by early settlers.

Discussion. This species is one of the most distinctive in its group. The numerous hairs on the basal part of the posterior section of the surstylus and on the posteromedial desclerotized region of sternite 5 give this area of the male terminalia an unusually hairy appearance (visible even in undissected specimens if not shrivelled). The anterior process of the anterior section of the surstylus is either more slender (L. kanata sp.n., L. tenuispina sp.n.) or stouter (L. angulispina sp.n.) in related species with rounded ventral lobe of the anterior section of the surstylus. Externally the very long enlarged acrostichals and short posteroapical mid-tibial bristles are distinctive (similar in L. kanata sp.n. but the acrostichals are usually shorter and the posteroapicals are usually longer). The female is highly distinctive because of its sharp-edged sternite 7 (see Description), a character shared only with the closely related, western L. neovomerata sp.n.