Anthomyza oblonga, Roháćek & Barber, 2016

Roháćek, Jindřich & Barber, Kevin N., 2016, Nearctic Anthomyzidae: a monograph of Anthomyza and allied genera (Diptera), Acta Entomologica Musei Nationalis Pragae (suppl.) 56, pp. 1-412 : 123-130

Anthomyza oblonga sp. nov.

( Figs 206 , 223 , 225–238 )

Type material. HOLOTYPE: ♂, “CAN:ON: SSMarie, Bristol Pl.Pk., 04.vii.2008, KNBar-ber, sweeps, Impatiens , Clematis , Equisetum , Rub-us, ferns, Phalaris 46°30.77’N 84°16.66’W ” and “ Holotypus ♂ Anthomyza oblonga sp. n., J. Roháček & K. N. Barber det. 2013” (red). The specimen is in perfect condition, with highly visible, partly exposed genitalia (see Fig. 206 ) ( CNCI, intact). PARATYPES: CANADA: MANITOBA: Ninette, 13.vi.1958, 1 ♀, C. D. F. Miller leg.( CNCI); Ninette, ex. Rudbeckia laciniota , 3.vi.1958, 1 ♂, maple / elm noodplain community, 12.vi.1958, 2 ♂♂ 2 ♀♀, J. F. McAlpine leg. ( CNCI). NEWFOUNDLAND: Port aux Basques, 6.viii.1961, 1 ♀, C. P.Alexander leg. ( USNM, 1 ♀ genit. prep.). NOVA SCOTIA: C[ape] B[reton] H[ighlands] N. P., Beulach Ban Falls, PG812870, swept along fast rocky stream, 8.vii.1983, 2 ♀♀; Truro, 14.vii.1983, 1 ♀, all J. R. Vockeroth leg. (all CNCI). ONTARIO: Algonquin, mixed wood, 1.vi.1991, 1 ♂, M. Barták leg.( MBPC, genit. prep.); Cootes Paradise nr. Dundas, sweeping undergrowth of deciduous forest, 20.viii.1994, 17 ♂♂ 9 ♀♀, J. Roháček leg. ( SMOC 14 ♂♂ 8 ♀♀, 3 ♂♂ 3 ♀♀ genit prep., NMPC 3 ♂♂ 1 ♀); Dubreuilville, 48°21.05'N 84°33.84'W, sweeping Diervilla , ferns, Clintonia , Cornus , Aralia , Eurybia , Vaccinium under Populus / Pinus , 10.vii.2010, 1 ♀, J. Roháček leg. ( SMOC, genit. prep.); Fergus, Malaise trap, 21.vii.1990, 1 ♂, S. A. Marshall leg. ( DEBU); Fort Frances, 10 mi E on Hwy. 11, 8–9.vii. 1978, 1 ♀, H. J. Teskey leg. ( CNCI); Greenwater P. Pk., Green Trail, 49°11.73'N 81°16.76'W, sweeps, Eurybia , Cornus , Clintonia , Diervilla , Aralia under Populus , 21.vii.2009, 1 ♂, K. N. Barber leg. ( DEBU 01502212); 7 mi E Grifnth, 22.vi.1985, 1 ♂, B. E. Cooper leg. ( CNCI); Icewater Creek WS [watershed], ~ 12.7 km NNE Searchmont, mi. 10.5 Whitman Dam Rd., alder thicket, 1.viii.1986, 1 ♀ ( CNCI); Icewater Creek WS [watershed], 46°53.7'N 84°03.4'W, sweeps, Thalictrum , Eupatorium [ Eutrochium ], sedge, fern in mixed forest, 7.vii.1998, 6 ♂♂ 4 ♀♀ ( CNCI 4 ♂♂ 2 ♀♀, 1 ♀ genit. prep., USNM 2 ♂♂ 2 ♀♀), sweeps, Thalictrum , sedge, fern, riparian mixed forest, 7.vii.1998, 3 ♂♂ 4 ♀♀ ( AMNH 2 ♂♂ 2 ♀♀, CNCI 1 ♂ 2 ♀♀, 1 ♂ 1 ♀ genit. prep.), sweeps, Thalictrum , Eupatorium [ Eutrochium ], fern in mixed forest, 10.vii.1998, 2 ♀♀ (1 ♀ genit. prep.), sweeps, trailside sedges, ferns, grasses, 10.vii.1998, 2 ♀♀, sweeps, trailside veg. incl. sedges, ferns, grasses, 17.vii.1998, 1 ♀ (genit. prep.) ( CNCI); King Mt., 26 km N S[ault] S[te.] Marie, riparian sweeps, 16.vi.1987, 1 ♀ ( CNCI), all K. N. Barber leg.; Moosonee, 51.24622°N 80.67281°W, Repl. 1 mesic, Malaise trap, 18–21.vi.2010, 2 ♀♀; Moosonee, 51.24466°N 80.67767°W, Repl. 2 mesic, Malaise trap, 21–24.vi.2010, 1 ♂, NBP Field Party leg. ( LEMQ); Moosonee, 51°14.75'N 80°40.33'W, sweeps, mostly Rubus , Ribes , under Populus , 9.vii.2014, 1 ♀; Moosonee, 51°14.79'N 80°40.35'W, 9.vii.2014, sweeps, mostly Solidago , Calamagrostis , 1 ♀; Moosonee, 51°16.33'N 80°39.11'W, sweeps, mostly Rubus , Impatiens , under Salix , Alnus , 10.vii.2014, 2 ♂♂ 5 ♀♀; Moosonee, 51°16.36'N 80°39.11'W, sweeps, railside ditch, mostly Equisetum ssuviatile , Carex spp., 11.vii.2014, 1 ♀, all K. N. Barber leg. (all CNCI); Ottawa, 15.vii.1957, 1 ♀ (genit. prep.), J. E. H. Martin leg., 30.vi.1963, 1 ♀, J. R. Vockeroth leg. ( CNCI); S[ault] S[te.] Marie, S of Algoma U[niversity] College, 46°29.9'N 84°17.2'W, sweeps, Impatiens under Populus / Betula , 13.vii.1998, 1 ♂ 1 ♀ (♀ genit. prep.); S[ault] S[te.] Marie, Baseline Rd., 46°31.40'N 84°24.45'W, sweeps, edge of forest, Solidago , Rubus , Equisetum , grasses, 25.vi.2005, 1 ♂, all K. N. Barber leg. (all CNCI); Sault Ste. Marie, Baseline Road, 46°31.40'N 84°24.40'W, sweeping Aster [ Doellingeria ], Rubus , Equisetum , Carex , Clematis , ferns under aspen ( Populus ), 7.vii.2010, 2 ♂♂ 2 ♀♀ (2 ♂♂ 1 ♀ genit. prep.), 12.vii.2010, 1 ♂ (genit. prep.), J. Roháček leg. ( SMOC); S[ault] S[te.] Marie, Baseline Rd., 46°31.40'N 84°24.40'W, Malaise #1, Aster [ Doellingeria ], Rubus , Equisetum , Carex , Solidago , in aspen clearing, 8–18.vii.2005, 1 ♀, sweeps, Aster [ Doellingeria ], Rubus , Equisetum , Carex , ferns under aspen, 25.vi.2005, 2 ♂♂, 26.vi.2005, 1 ♂ 2 ♀♀, 22.vii.2010, 1 ♀ ( CNCI), 19.vi.2011, 1 ♂ 2 ♀♀ ( INHS), 29.vii.2012, 2 ♀♀, sweeps, mostly ferns under aspen, 19.vi.2011, 3 ♂♂ 2 ♀♀ ( LACM), 27.vii.2012, 1 ♂ 3 ♀♀ (1 ♀ genit. prep.), 28.vii.2012, 2 ♂♂ 1 ♀ (1 ♂ genit. prep.), 29.vii.2012, 2 ♀♀ ( CNCI), K. N. Barber leg.; S[ault] S[te.] Marie, Birchwood Pk., mixed forest, 15.vi.1986, 1 ♂ ( MCZC), 28.vi.1986, 1 ♂, 6.vii.1986, 1 ♂ ( CNCI); same locality but 46°30.7'N 84°15.6'W, sweeps, mostly Impatiens , under Betula / Acer , 19.vi.1998, 3 ♀♀ (1 ♀ genit.prep.), 23.vi.1998, 1 ♀, sweeps, Impatiens , under Betula / Acer , 27.vi.1998, 1 ♀ (genit. prep.), sweeps, graminoids, Impatiens , ferns under Betula / Acer , 17.ix.2004, 1 ♀; same locality but 46°30.67'N 84°15.63'W, sweeps, Rubus , Aralia , graminoids, ferns, under Betula / Acer , 29.vi.2008, 1 ♂, sweeps, mostly Impatiens , fern, Aster [ Eurybia ], 23.viii.2009, 1 ♂ (all CNCI), all K. N. Barber leg.; S[ault] S[te.] Marie, Bristol Place, 28.vi.1987, 1 ♀, 1.vii.1987, 1 ♂, K. N. Barber leg. ( CNCI); S[ault] S[te.] Marie, Bristol Pl[ace] Pk., 46°30.8'N 84°16.6'W, sweeps, Impatiens under Betula / Acer , 9.vii.1998, 1 ♂ 1 ♀, sweeps, Clematis , Rubus , Impatiens , grasses, 28.v.1999, 1 ♂, sweeps, mostly Impatiens , Clematis , Rubus , grasses, 11.vi.1999, 2 ♂♂ ( CNCI); same locality but 46°30.77'N 84°16.66'W, sweeps, Impatiens , Clematis , Equisetum , Rubus , ferns, Phalaris , 29.vi.2008, 2 ♂♂ 3 ♀♀ ( CASC), 30.vi.2008, 1 ♂ 1 ♀ ( MCZC), 1. vii.2008, 2 ♀♀, 4.vii.2008, 6 ♂♂ 2 ♀♀ (1 ♂ wing illustration, one pair in copula), 5.vii.2008, 1 ♂ 2 ♀♀ ( CNCI), 9.vii.2008, 2 ♂♂ 3 ♀♀ ( DEBU, 1 ♀ genit. prep.), 11.vii.2008, 7 ♂♂ 3 ♀♀ (1 ♀ genit. prep.), 13.vii.2008, 1 ♀, 27.vii.2009, 1 ♂ 5 ♀♀ ( CNCI), 21.vii.2014, 1 ♂ 1 ♀ ( SMOC), all K. N. Barber leg.; S[ault] S[te.] Marie, Finn Hill, 46°31.6'N 84°17.4'W, sweeps, vegetation under Populus , 4.vii.2002, 1 ♀; S[ault] S[te.] Marie, Fish Hatchery Road, along Coldwater Ck., 46°34.33'N 84°17.23'W, sweeps, trailside Clematis , Eutrochium , 17.vi.2010, 1 ♂; S[ault] S[te.] Marie, Florwin Dr. greenbelt, 46°30.3'N 84°17.2'W, sweeps, Impatiens under Acer / Betula , 23.vi.1999, 1 ♀; S[ault] S[te.] Marie,Sault Coll[ege] Woodlot, 46°32.08'N 84°18.25'W, sweeps, Clintonia , ferns, under Acer , 31.v.2010, 1 ♂, all K. N. Barber leg. (all CNCI). QUEBEC: Abbotsford, 4.vi.1937, 1 ♂, G. E. Shewell leg.; Beechgrove, 7. vi.1955, 1 ♀, J. F. McAlpine leg.; Beechgrove, 45°39'N 76°08'W, 29.vi.1962, 1 ♂, J. R. Vockeroth leg.; Bolton Pass, Knowlton, 800', 5.vi.1963, 1 ♂, J. G. Chillcott leg. (all CNCI); 1.2 km E Bristol, Silver Creek, 45°31'N 76°27'W, noodplain meadow, 5.vi.1996, 1 ♀, L. Dumouchel leg. ( LEMQ 0040277); Gatineau Pk., Harrington Lk., 3.vii.1963, 1 ♂, J. R. Vockeroth leg.; Lac Roddic, 16 km S Maniwaki, 23.vi.1991, 1 ♂ 1 ♀, M. Barták leg. ( MBPC, both genit. prep.); Magog, 1.vi.1965, 1 ♀, D. M. Wood leg. (genit. prep.); Old Chelsea, 18.vi.1963, 1 ♂, J. R. Vockeroth leg. (genit. prep.); Old Chelsea, King Mt., 26.v.1963, 1 ♂, J. G. Chillcott leg.; Wakeneld, 26.vi.1946, 1 ♀, 9.vii.1946, 1 ♀, G. E. Shewell leg. (all CNCI). SASKATCHEWAN: Kenosee, 7.vi.1958, 2 ♂♂ 7 ♀♀; Saskatoon, 9.vii.1951, 1 ♀, all A. R. Brooks leg. (all CNCI). UNITED STATES OF AMERICA: CONNECTICUT: Canaan, 17.viii.1952, 1 ♀, A. Stone leg.; Redding, 8.vi.1928, 1 ♀ (genit. prep), A. L. Melander leg. (both USNM). ILLINOIS: Savanna, 13.vi.1917, 1 ♂, [no collector] ( INHS 40,188). INDIANA: Lafayette, 24.v.1917, 1 ♂, J. M. Aldrich leg. ( USNM). MARYLAND: Bethesda, 14.viii.1981, 1 ♀, G. C. Steyskal leg. ( USNM); Montgomery Co., Bethesda, 5.v.1968, 3 ♂♂, L. V. Knutson leg., 26.v.1968, 1 ♂, G. Steyskal leg.; Cabin John, 21.vii.1921, 1 ♂, J. R. Malloch leg. (Malloch det. as A. tenuis ); Montgomery Co., Dickerson, 14.vii.1974, 1 ♂ (genit. prep.), G. A. Foster leg.; Glen Echo, 23.vii.1922, 1 ♂, J. R. Malloch leg.; Lavale, 9.v.1970, 1 ♂ (genit. prep., left wing and apical half of right wing missing), G. Steyskal leg. (all USNM); Plummers Is., 12.v.1907, 1 ♂, W. L. McAtee leg. (with det. as A. tenuis ), 9.viii.1909, 1 ♀ (genit. prep.), Barber & Schwarz leg., 28.vii.1912, 1 ♀, H. L. Viereck leg., 5.v.1914, 1 ♂, 10.v.1914, 1 ♂, at light, 13.vi.1914, 1 ♀ (genit. prep.), R. C. Shannon leg., Malaise trap, 8–20.vii.1968, 1 ♂ (genit. prep.), Paul Spangler leg. (all USNM). MASSACHUSETTS: Franklin Co., ~0.5 km E Farley, 42°36.16'N 72°25.94'W, sweeps, asters, ferns, Impatiens , Rubus , under canopy, 26.vii.2006, 2 ♂♂ 3 ♀♀, K. N. Barber leg. ( CNCI, 1 ♀ genit. prep.); Middlesex Co., Lincoln, Malaise trap, 4–8.vi.1952, 1 ♀, E. T. Armstrong leg. ( USNM, genit. prep.). MICHIGAN: Hillsdale Co., 21.v.1960, 1 ♂, R. & K. Dreisbach leg. ( USNM). MINNESOTA: Itasca Pk., 12.vii.1952, 1 ♂, [no collector] ( AMNH). NEW HAMPSHIRE: Mt. Washington, 18.vii. [-], 1 ♀, C. W. Johnson leg. ( MCZC). NEW YORK: Bemus Pt., Chautauqua Lk., swampy woods, 31.v.1963, 1 ♀, W. W. Wirth leg. ( USNM); Ithaca, 24.v.1900 [?], 1 ♂, [no collector] ( AMNH, genit. prep., wings in genit. vial); New York, 31.v.1923, 1 ♂, A. H. Sturtevant leg.; Tompkins Co., Ringwood Res., swamp, 16–17.vi.1963, 1 ♀, W. W. Wirth leg.; Rome, 24.vi.1935, 1 ♀, H. K. Townes leg. (all USNM); Whiteface Mt., 4600–4872', 19.vii.1962, 1 ♂, J. R. Vockeroth leg. ( CNCI). NORTH CAROLINA: Buncombe Co., Blue Ridge Pkwy. at Craggy Gardens, 35.70°N 82.39877°W, 5400', sweep forest path and clearing, 17.viii.2007, 1 ♀, T. A. Wheeler leg. ( LEMQ); Swain Co., Rte 441, 3 mi N Cherokee, Great Smoky Mountains National Park, 35°31.3'N 83°18.5'W, 2000', 27.v.1999, 1 ♀, S. D. Gaimari leg. (99-5, Nat’l Pk. Svc. Permit #GRSM-99-074) ( USNM). ENNSYLVANIA: Dauphin Co., Grantville, 24.v.1962, 1 ♀, J. R. Vockeroth leg. ( CNCI, genit.prep.); Roxborough, 23.v.1909, 1 ♀, [no collector] ( USNM, genit. prep.). VIRGINIA: Bland Co., Brushy Mt. at Rd. 623, 37.05229°N 81.30209°W, sweep forest edge, 15.viii.2007, 6 ♂♂ 5 ♀♀, J. Mlynarek leg., 4 ♂♂ 1 ♀ ( LEMQ 0040768–72, 1 ♂ genit. prep.), T.A. Wheeler leg., 1 ♂ ( LEMQ 0040310, genit. prep.), A. MacLeod leg.; Chain Bridge, 7.v.1922, 1 ♀ (genit. prep.), 20.viii.1922, 1 ♀, 14.v.1924, 1 ♂, J. R. Malloch leg.; Fairfax Co., Dead Run, 28.vii.1915, 1 ♂ 1 ♀, R. C. Shannon leg. (♀ genit. prep.); Falls Church, Holmes Run, light trap, 24.viii.1960, 1 ♀, W. W. Wirth leg. (all USNM); Page Co., G.Washington N. F., Gap Creek Trail, 38.70764°N 78.56077°W, 1662', sweep forest path at creek, 19.viii.2007, 1 ♀, J. Mlynarek leg. ( LEMQ 0040534); Great Falls, “ 12-vi ”, 1 ♀, N. Banks leg. ( MCZC); Giles Co., Mountain Lake Biol. Stn., 37°22'31"N 80°31'18"W, sweep nr. station, 20.v.2005, 1 ♂, S.A. Marshall leg. ( DEBU 00252870); near Plummers Island, MD [Maryland], at light, 20.v.1914, 1 ♀ (genit. prep.), R. C. Shannon leg. ( USNM); Shenandoah N. P., mi. 65–100, sweeps, 29.v.1979, 2 ♂♂, M. J. Sharkey leg. ( DEBU); Hawksbill Gap, Shenandoah N. P., 1600 m, 17.viii.1981, 1 ♂ 1 ♀, J. R. Vockeroth leg. ( CNCI); Shenandoah Co., Mt. Jackson, 25.v.1962, 1 ♂ 1 ♀, J. G. Chillcott leg., 2 ♂♂, J. R. Vockeroth leg. ( CNCI); Tazewell, Burkes Garden, Sta[tion] Spr[in]g, 37°05.9'N 81°22.4', 960 m, 18.v.2005, 4 ♂♂, W. N. & D. Mathis leg. ( USNM). WEST VIRGINIA: Grant Co., Dahle Soda, 13. vi.1986, 1 ♂, A. L. Norrbom leg. ( USNM).

Other material examined (not included in type series). Provenance unknown, “Loew Coll.”, “Type 13427” (red label), 1 ♀, ( MCZC, genit.prep., erroneously labelled a syntype of Anthophilina tenuis Loew ). CANADA: ONTARIO: Moosonee, 51°16.33'N 80°39.11'W, sweeps, mostly Rubus , Impatiens , under Salix , Alnus , 10.vii.2014, 1 ♀, K. N. Barber leg. ( CNCI, deformed postabdominal tergites); S[ault] S[te.] Marie, Bristol Pl[ace] Pk., 46°30.77'N 84°16.66'W, sweeps, Impatiens , Clematis , Equisetum , Rubus , ferns, Phalaris , 21.vii.2014, 3 ♂♂, K. N. Barber leg. ( SMOC, used for molecular work). SASKATCHEWAN: Kenosee, 7.vi.1958, 1 ♀ ( CNCI, headless, genit. prep.). UNITED STATES OF AMERICA: NEW HAMPSHIRE: “N.H.”, “205”, “Loew Coll.”,“ Type 14558” (red label), 1 ♀ ( MCZC, headless, double mount with a ♀ of Arganthomyza duplex on the same pinned bricket, erroneously labelled as type specimens of Anthophilina terminalis Loew ). NEW YORK: Delaware Co., Franklin Mtn. nr. Oneonta, 3.vii.1980, 1 ♀, D. J. Bickel leg. ( MCZC, head glued to pin, genit. prep.).

Other A. macra group material of questionable identity ( Anthomyza sp. cf. oblonga ). CANADA: ONTARIO: S[ault] S[te.] Marie, Baseline Rd., 46°31.40'N 84°24.40'W, sweeps, Aster [ Eurybia ], Rubus , Equisetum , Carex , ferns, under aspen, 8.viii.2005, 1 ♀ (genit. prep.); S[ault] S[te.] Marie, Birchwood Park, mixed forest, 28.vi.1986, 1 ♀ (genit. prep.), both K. N. Barber leg. (both CNCI). UNITED STATES OF AMERICA: PENNSYLVANIA: Dauphin Co., Grantville, 24.v.1962, 1 ♀, J. R. Vockeroth leg. ( CNCI, genit. prep.).

Description. Male. Total body length 2.02–2.66 mm. Externally extremely similar to A. tenuis including colouration and chaetotaxy, thus body bicolourous and sparsely pale grey microtomentose as in the latter species. Head shape as in A. tenuis , about as long as high. Colouration of head practically identical with that of the latter species including microtomentose pattern of all its parts. Also mouthparts very similarly coloured. Cephalic chaetotaxy as in A. tenuis , only pvt somewhat longer (usually slightly longer than half length of vti), 3–4 (usually 3) pairs of medial microsetulae in anterior third of frons, 9–10 postocular setulae; vi long as in A. tenuis ; subvibrissa weak but usually distinctly longer than anterior peristomal setula. No differences in colour and chaetotaxy of palpus. Eye large and oval as in A. tenuis , with longest (oblique) diameter 1.3–1.4 times as long as shortest. Gena higher than that of A. tenuis , about 0.12 times as long as shortest eye diameter. Also antenna (including arista) as in the latter species although whitish marginal cilia on 1st nagellomere slightly longer.

Thorax dark brown dorsally and yellow laterally and ventrally as in A. tenuis but the pattern is yet more variable. In lightest specimens the yellow is extended not only on humeral and notopleural areas but also on lateral sides of mesonotum (up to supralar seta); even disc of scutellum is broadly yellow leaving only its sides brownish. In darkest specimens, on the contrary, humeral callus and a band across dorsal margin of mesopleuron and pteropleuron are also brownish, in addition to darkened laterotergite, mediotergite, subscutellum and scutellum. Intermediates between these extremes are frequent. Thoracic chaetotaxy: hu, npl(s), prs, sa and pa as in A. tenuis ; also both (postsutural) dc similar; 5–6 dc microsetae in front of anterior dc, the hindmost only slightly longer than others; ac microsetae less numerous than in A. tenuis , normally in only 2 rows on suture (plus a few single microsetae laterally to them), usually ending slightly behind anterior dc, only rarely reaching up to posterior dc; 2 sc and 2 stpl as in A. tenuis but upcurved setulae on sternopleuron more numerous (4–5) and differently arranged, in more or less perpendicular row with most dorsal setulae longer and situated almost between stpl macrosetae; no setula in front of anterior stpl. Scutellum formed as in A. tenuis but usually paler on disc medially, sometimes largely yellow (see above). Legs yellow as in A. tenuis , with only distal third to half of apical segment of all tarsi brownish. f 1 with ctenidial spine about as long as maximum width of t 1; other pedal chaetotaxies as in A. tenuis . Wing ( Fig. 223 ) closely resembling that of A. tenuis , with hyaline pale ochreous brown membrane and ochreous veins. Venation as in A. tenuis , only with r-m sometimes situated in middle of cell dm, and terminal section of CuA 1 slightly to distinctly longer than dm-cu. Wing measurements: length 2.30–2.74 mm, width 0.79–0.97 mm; Cs 3: Cs 4 = 1.48–1.84, rm\ dm-cu: dm-cu = 1.95–2.79. Haltere yellowish white, knob often lighter.

Abdomen colouration and structures very similar to those of A. tenuis . Preabdominal terga brown to pale brown (sometimes slightly paler dorsomedially), distinctly lighter than mesonotum or epandrium. T1 concolourous or slightly paler than T2. T2–T5 as in A. tenuis . Preabdominal sterna somewhat wider than in A. tenuis , pale yellow and with denser setosity. S1 as in A. tenuis , S2–S5 slightly to distinctly wider than long, becoming wider and more transverse posteriorly; S5 the largest and widest, posteriorly distinctly widened. T6 as in A. tenuis but somewhat longer, seemingly bipartite, with dorsomedial unpigmented part narrower. S6–S8 dorsally fused and more or less asymmetrical as usual. S6 and S7 ochreous to yellow in pale specimens, brown and concolourous with T 5 in dark ones, with anterior ledge-like margins always darker brown. Both S6 and S7 usually with more setulae (S6 with 3–5, S7 with 2–4). S8 long, brown to pale brown as T5 or (in pale specimens) with lightened marginal areas.

Genitalia. Epandrium ( Figs 225, 226 ) very broad as in A. tenuis but smaller, with similar chaetotaxy, usually with setae denser laterally; anal nssure higher (longer) and cercus slightly larger (compared to epandrium) than in A. tenuis . Medandrium distinctly higher, with dorsolateral corners small ( Fig. 225 ). Gonostylus ( Figs 225, 226, 231 ) distinctive, dissimilar to those of all relatives, roughly suboblong, relatively narrow but with outer side convex, with both distal corners more or less angular, setose only on inner side and externally largely micropubescent, with only anterior marginal band bare ( Fig. 226 ). Hypandrium ( Fig. 227 ) as in A. tenuis but more robust anteriorly. Transandrium ( Fig. 228 ) generally constructed as in relatives, somewhat wider and with terminal arms of caudal process thicker than those of A. tenuis . Pregonite ( Fig. 227 ) similar to that of A. tenuis , 3 anterior and only 4 posterior setae (latter on short lobe-like process). Postgonite more slender (only when viewed in pronle) than that of A. tenuis and with 1–2 setiform microsensilla below 1 usual seta inserted more proximally at anterior margin ( Fig. 227 ). Aedeagal part of folding apparatus with the same armature as in A. tenuis ; connecting sclerite also similar although somewhat paler and less sclerotized; basal membrane with dense short excrescences more spine-like ( Fig. 227 ). Phallapodeme more robust, particularly the fulcrum ( Fig. 230 ). Phallophore as in A. tenuis . Saccus ( Fig. 230 ) voluminous but somewhat smaller and its membranous distal part with markedly fewer spines than that of A. tenuis hence resembling that of A. silvatica . Filum ( Fig. 230 ) compact ribbon-shaped, largely dark, fading only towards apex which is (in contrast to A. tenuis ) parallel-sided with blunt tip ( Fig. 229 ). Ejacapodeme larger than in relatives ( Fig. 230 ).

Female. Similar to male unless mentioned otherwise. Total body length 2.46–3.21 mm. Cephalic and thoracic setae longer and thicker. Orbit rarely (2 specimens seen) with 1–3 additional microsetulae among ors. Antenna with 1st nagellomere only sometimes darker yellow around base of arista. Mesonotum with ac microsetae sometimes more numerous forming up to 4 rows on suture. Ctenidial spine on f 1 distinctly longer and thicker, longer than maximum width of t 1. Wing measurements: length 2.73–3.25 mm, width 0.93–1.13 mm; Cs 3: Cs 4 = 1.33–1.68, rm\dm-cu: dm-cu = 1.85–2.82. Preabdomen with terga more transverse, bicolourous, typically dorsally largely yellow and laterally brown (cf. Fig. 232 ). T1 more or less ochreous to pale brown; T2 not only laterally but also anteriorly brownish, otherwise yellow, or (more rarely, in dark specimens) completely pale brown. T3–T5 largely yellow, only laterally (on bent sides) brown, with dark parts sharply contrasting with yellow dorsum of sclerites. More rarely T3–T5 (or only some of them) with dorsal pale areas smaller and ochreous and/or with dorsomedial pale brown spot. Preabdominal sterna pale yellow, narrower than in male but also densely (more than in A. tenuis ) setose; S2 and S3 about as long as wide; S4 and S5 wider than long, both slightly transverse. S5 the largest sternum, about as wide as S6.

Postabdomen ( Figs 234, 238 ) relatively elongate, extremely similar to that of A. tenuis and, consequently, mainly the differences are stressed below. T6 largely blackish brown but anteriorly with larger yellow marginal area (longest medially, Fig. 234 ). S6 somewhat smaller (particularly shorter) than in A. tenuis . T7 usually slightly shorter and with more setae, always with sides convex ( Fig. 234 ) to straight; S7 also very similar, narrow and elongate; enlarged micropubescence of membrane between T7 and S7 somewhat different (cf. Fig. 238 ). T8 of almost the same shape as that of A. tenuis and with similar sparse micropubescence but sometimes darker, more rarely somewhat shorter and more transverse. S8 hardly different from that of A. tenuis . Genital chamber ( Figs 233, 236 ) with similar posterior pair of bent sclerites ( Fig. 233 ), but elongate annular sclerite below them anteriorly more dilated (cf. Fig. 236 ) and in pronle distinctly more curved ( Fig. 233 ) than that of A. tenuis ; terminal part of genital chamber without distinct plate-like sclerite (or this structure is membranous). Ventral receptacle ( Fig. 233 ) also closely resembling that of A. tenuis but with curved terminal end also nnely ringed. Accessory gland vesiculate ( Fig. 233 ), on distinctly subterminally dilated and partly ringed duct. Spermathecae (1+1) cone-shaped as those of A. tenuis but terminally more slender and tapered ( Fig. 235 ) and with short basal part markedly narrower than maximum width of distal part, the latter being more densely transversely striated ( Figs 235, 237 ); spermathecal ducts as in A. tenuis . T10 ( Fig. 234 ) shorter and more transverse than that of A. tenuis , otherwise similar to that of latter species; also S10 hardly different ( Fig. 238 ). Cercus slender, with chaetotaxy as in A. tenuis but with dorsopreapical seta often longer ( Fig. 234 ).

Discussion. Owing to the highly characteristic suboblong shape of the gonostylus, Anthomyza oblonga sp. nov. is the most distinctive of the Nearctic species of the A. macra group. In addition, there are several more features in the male genitalia distinguishing it from relatives (particularly from the externally most similar A. tenuis ), viz. the larger medandrium, the robust fulcrum of the phallophore, fewer spines in the saccus of the distiphallus and the blunt apex of the nlum. However, in the female sex it might sometimes be very difncult to distinguish it from A. tenuis because their postabdominal structures are very similar. The pale specimens of A. oblonga can be easily recognized in having the disc of the scutellum contrastingly yellow but in darker females (with scutellum brownish with or without pale brown medial area) it is necessary to carefully compare other characters, particularly the yellow pattern of the preabdominal terga (more contrasting in A. oblonga ), the shape of T7 (laterally convex to straight in A. oblonga ), the sclerotization of the genital chamber (shape of annular sclerite) and the form and striation of the spermathecae (see the key). However, despite the above female resemblances (with A. tenuis ), A. oblonga is probably more closely allied to A. silvatica than to A. tenuis sharing with it the similar armature of the saccus (with spines concentrated more basally near the internal coiled structure) and the more densely striated spermathecae. The E. Palaearctic species A. decolorata Roháček, 2009 also shares these characters but further resembles A. oblonga in the very projecting posterior corner of the gonostylus, the blunt apex of the nlum (all other species of the group have the nlum apically lanceolate) and the female preabdominal terga strongly desclerotized and depigmented.All these characters are probably apomorphic and may demonstrate a sister-species relationship of the latter pair.

Etymology. The species name is a Latin adjective (oblongus, -a, -um), meaning oblong, to renect the suboblong shape of its gonostylus.

Biology. Anthomyza oblonga and A. silvatica frequently co-occur in Ontario, Canada. Here, this habitat is the same as that of three or even four (including the recently transferred Arganthomyza vittipennis ) eastern species of Arganthomyza (see Figs 69 , 149 ) – mixed vegetation within or on the edge of mesic mixed forest with ferns possibly representing an indicator of appropriate habitat that often has at least a component of Populus tremuloides (in east). A very notable exception is the Ontario: Moosonee site under Salix and Alnus with no ferns or Populus (in immediate vicinity) and where all three species of the A. macra group were found with three species of Arganthomyza (see discussion under A. tenuis ). Dennitive plant hosts have not been identined for any of these species. Other label references include sweeping in habitats such as “ maple / elm noodplain community”, “along fast rocky stream”, “noodplain meadow” and “swamp”. Anthomyza oblonga has been collected as early as 5 May (Maryland: Bethesda & Plummers Island) and as late as 17 September (Ontario: Sault Ste. Marie – Birchwood Pk.).

Distribution. This is a fairly widely distributed species in the east and not yet known from west of Manitoba. Canada: Manitoba, Newfoundland, Nova Scotia, Ontario, Quebec, Saskatchewan; United States of America: Connecticut, Illinois, Indiana, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New York, North Carolina, Pennsylvania, Virginia, West Virginia (see Table 2).

Figures

Figs 203–206.Primary types of the Nearctic species of the Anthomyza macra group and their habitat. 203 – A. tenuis (Loew, 1863), lectotype male, laterally and its type labels, body length 2.74 mm; 204 – habitat of the Nearctic species of the A. macra group in Moosonee (Canada: Ontario); 205 – A. silvatica sp. nov., holotype male, laterally, body length 2.50 mm; 206 – A. oblonga sp. nov., holotype male, laterally, body length 2.65 mm. Photo by K. N. Barber (Fig. 204) and J. Roháček (others).

Figs 222–224. Wings of the Nearctic species of the Anthomyza macra group. 222 – A. tenuis (Loew, 1863) male, wing length 2.8 mm (Canada: Alberta); 223 – A. oblonga sp. nov., paratype male, wing length 2.7 mm (Canada: Ontario); 224 – A. silvatica sp. nov., paratype male, wing length 2.5 mm (Canada: Ontario). Photo by K. N. Barber.

Figs 225–231. Anthomyza oblonga sp. nov., paratype male (Canada: Ontario). 225 – external genitalia, caudally; 226 – the same, laterally; 227 – hypandrial complex, laterally; 228 – transandrium, caudally; 229 – apex of nlum, lateroventrally (widest extension); 230 – aedeagal complex, laterally; 231 – gonostylus,sublaterally (widest extension, micropubescence omitted). Scales = 0.05 mm (Fig. 229) and 0.1 mm (others).

Figs 232–238. Anthomyza oblonga sp. nov., paratype female (Canada: Ontario). 232 – abdomen, dorsally; 233 –female genital chamber and S8 (with setosity omitted), laterally; 234 – postabdomen, dorsally; 235 – spermatheca; 236 – internal sclerites, ventrally; 237 – spermatheca; 238 – postabdomen, ventrally. Scales = 0.3 mm (Fig. 232), 0.05 mm (Figs 235, 237) and 0.1 mm (others).

Figs 66–69.Living Arganthomyza carbo Roháček & Barber, 2013 and its habitat. 66 – A. carbo, male dorsally, body length ca. 2.7 mm; 67 – same specimen, laterally (Canada: Ontario:Sault Ste. Marie); 68 – same, enlarged, frontally; 69 – undergrowth of humid aspen forest at Baseline Rd. in Sault Ste. Marie, habitat of A. carbo, A. vittipennis, A. bivittata, and A. duplex. Photo by J. Roháček. Adapted from ROHÁĆEK & BARBER (2013: Figs 48–51).

Figs 146–149. Living Arganthomyza duplex Roháček & Barber, 2013 and its habitat. 146 – mating pair of A. duplex, laterally, body length ca. 2.3–2.9 mm; 147 – male, laterally, body length 2.5 mm; 148 – female, laterally, body length ca. 3 mm; 149 – fern-dominated undergowth of mixed forest, habitat of A. duplex and A. carbo (all photos from Canada: Ontario: Dubreuilville). Photo by J. Roháček. Fig. 146 adapted from ROHÁĆEK & BARBER (2013: Fig. 100).