Arganthomyza duplex, Rohacek & Barber, 2013

Roháček, Jindřich & Barber, Kevin N., 2013, A worldwide review of the genus Arganthomyza Roháček, with revision of the Nearctic species (Diptera: Anthomyzidae), Zootaxa 3604 (1), pp. 1-72 : 26-34

Arganthomyza duplex sp. n.

Figures 3 , 100, 101 , 106–120 , 169

Type material: Holotype ♂ labelled: “CAN: ON: ~20kmE Nipigon, Hwy. #17, rest area, 31.vii.2008, KNBarber, sweeps, Aster [ Eurybia ], Rubus , Aralia , Diervilla , 48°58.00’N 87°59.09’W ” and “ HOLOTYPUS ♂, Arganthomyza duplex sp.n., J. Roháček & K. N. Barber det. 2011” [red label] ( DEBU, intact). Paratypes: CANADA: Alberta: A[lberta] O[il] S[ands] E[nvironmental] R[esearch] P[rogram], Mildred Lake facilities, Malaise trap, 16.ix.1979, 1♀, G. J. Hilchie & J. K. Ryan ( PMAE 1983.002); Banff Nat. P., 15 mi E Mt. Eisenhower Jct., 27.vii.1967, 1♂, S. P. Whitney ( USNM); Bilby, 1.vii.1924, 1♀, O. Bryant ( CASC); ~1.2 km S Cadomin, entrance to Whitehorse Wildland P. Pk., 53°00.70’N 117°20.05’W, sweeps, Bromus inermis , Hedysarum boreale , 23.vii.2008, 2♀, K. N. Barber leg. ( DEBU); Cypress Hills Prov. Pk., sweeping Pinus contorta forest meadow, 14.vii.1980, 1♂, G. Gibson leg. ( DEBU); Dunvegan, S side Peace River, pan traps in forest, 19–28.vi.1995, 1♂ ( LEMQ 0040200), 28.vi.–11.vii.1995, 17♂ 4♀ ( LEMQ 0040188-193, -195-197, -198, -205, -212-214, -219-221, - 224, -225, -231, -232), 11–25.vii.1995, 9♂ 1♀ (1♂ headless LEMQ 0040194, -199, -201-203, -208-211, -222), 25.vii.–1.viii.1995, 2♂ 1♀ ( LEMQ 0040204, -23, -30), S. Boucher leg. ( LEMQ); Dunvegan, N side Peace River, pan traps in grasses, 6–19.vi.1995, 2♀ ( LEMQ 0040248, -49), 19–28.vi.1995, 10♂ 7♀ ( LEMQ 0040227-29, -33, - 37-40, -46, -47, -50, -60, -71-75), 28.vi.–11.vii.1995, 14♂ 4♀ ( LEMQ 0040185, -216-218, -226, -251-254, -257, - 262-267, -269, -270, 1♂ genit. prep.), 11–25.vii.1995, 10♂ 1♀ ( LEMQ 0040215, -41-45, -55, -56, -58, -59, -61), 25.vii.–1.viii.1995, 3♂ 1♀ ( LEMQ 0040206, -34-36), S. Boucher leg. ( LEMQ); Dunvegan, N shore of Peace River, sweep grasses at edge of agricultural field, 13.vii.1997, 11♂ 2♀, T. A. Wheeler leg. ( LEMQ 0040165, -66, - 68, -69, -73-78, -82-84); as above but sweep grasses along agricultural field, 14.vii.1997, 2♀, T. A. Wheeler leg. ( LEMQ 0040171, -72); Edmonton, 20.viii.1936, 1♀, E. H. Strickland leg. ( CNCI); Edmonton, Ft. Edmonton Pk., River Loop Trail, 53°30.3’N 113°34.2’W, sweeps, trailside veg. under Populus / Betula , 14.vii.1999, 11♂ 6♀, K. N. Barber leg. ( DEBU, 1♀ genit. prep.); Elkwater Park, 12.vii.1952, 2♂ 1♀, A. R. Brooks leg., 1♂ 3♀, L. A. Konotopetz leg., 21.vii.1956, 1♂, O. Peck leg. (all CNCI); [Fort] McMurray, 20.vi.1953, 2♂ (1♂ genit. prep.), 3.vii.1953, 1♂ 1♀, 10.vii.1953, 1♂ 3♀, 30.vii.1953, 1♀, 8.viii.1953, 8♂ 7♀, 10.viii.1953, 3♂ 2♀ (1♀ genit. prep.), G. E. Ball leg. ( CNCI); Hinton, old carrion, 12.viii.1980, 1♀, S. Marshall leg. ( DEBU); 2 mi S Jasper, 29.vii.1967, 4♂ 4♀, S. P. Whitney ( USNM); Lamont Co., Ukalta Dunes, 53.9747°N, 112.5072°W, 625 m, forest & clearing, yellow pans, 6.viii.2010, 2♂ 2♀, M. Buck & S. Widen leg. ( PMAE); Waterton Lakes Nat. P., 1–5.vii.1980, 2♂ 5♀, 7–12.vii.1980, 1♀, H. J. Teskey leg. ( CNCI); Waterton Lakes National Pk., N5436608.840 E300066.759, pan, burned, unsalvaged rep.2, 25.vii.–1.viii.2000, 1♂, E. Kinsella ( BDUC); Westlock Co., Bridge Lk. N[atural] A[rea], 54°10.45’N 113°29.95’W, 675 m, sweeps, Rubus , Aralia , Rosa under Populus , 27.vii.2011, 2♀, M. Buck & K. N. Barber leg.; Westlock Co., Halfmoon Lk. N. A., Ghost Horse Hills Tract, 54°03.06’N 113°22.75’W, 660 m, sweeps, Rubus , Aralia , grasses under Populus , 27.vii.2011, 13♂ 4♀, M. Buck & K. N. Barber leg. (all PMAE). British Columbia: Atlin, 2200’, 4.vi.1955, 1♀, 7.vii.1955, 1♂ 1♀, B. A. Gibbard leg.; Canim Lake, 22.vi.1938, 2♀, G. S. Walley leg. (all CNCI); Chetwynd, 615 m, 25.vi.1978, 5♂ 3♀, P. H. Arnaud, Jr. leg. ( CASC, 1♂ 1♀ genit. prep.); Cultus Lake, 3.vii.1948, 1♂, 10.vii.1948, 1♀, 15.vii.1948, 1♂ 1♀, H. R. Foxlee leg. ( CNCI); Fernie, Annex Pk., 49°30’43”N 115°04’07”W, 2.viii.2010, 1♂, S. M. Paiero leg. ( DEBU 00334436); Glacier National Park, ca. 1.6 km N Glacier, 14.vii.1974, 4♂ 2♀, P. H. Arnaud, Jr. leg. ( CASC); Hagensborg, 12.vii.1992, 1♂, A. Borkent leg.; 5 mi E Hope, 11.vii.1973, 3♀, H. J. Teskey leg. (all CNCI); Kaslo, 13.vi.[no year], 1♀, H. G. Dyar leg.; Kaslo, 16.vii.[no year], 1♂, A. N. Caudell leg.; Kaslo, 25.vi.[no year], 1♀, 16.vii.[no year], 1♀, 17.vii.[no year], 1♀, R. P. Currie leg. (all USNM); Kimpton Creek, Hwy 93, 23.vi1982, 1♀, B. V. Peterson leg. ( CNCI); Kinbasket Lake, BC Hydro drawdown study, 21.vi.2010, pan trap, 12PCOT15, 1♀, 12PLRT01, 1♀, 12PLRT15, 2♀, Malaise trap, 12PLRT01, 1♀, Beauchesne & Assoc Ltd. leg. ( RBCM); King Salmon L., 58°43’N 132°54’W, 15.vii.1960, 1750’, 1♂ 3♀, W. W. Moss leg. ( CNCI); as above but dry burnt ridge, 1750’–2000’, 4♀, R. Pilfrey leg. ( CNCI); Kiskatinaw Public Campground, Alaska Highway DC-20 (31.4 km), 26.vi.1978, 1♂ 1♀, P. H. Arnaud, Jr. leg. ( CASC); Lac La Hache, 15.vii.1973, 1♀, H. J. Teskey leg.; Liard R. Hot Spr[in]gs, 1725’, 24.viii.1962, 1♂, P. J. Skitsko leg.; Liard Hot Spring, mi.496, 1500’, Alaska Hwy, 9–10.vii.1959, 1♀, E. E. MacDougall leg.; McQueen L., 10 mi N Kamloops, 25.vi.1973, 1♂, H. J. Teskey leg. (all CNCI); Mt. Robson Prov. Pk., Hwy #16, small road towards Mt. Robson, 53°03’N 119°15’W, forest floor, swamp, (Universität Bielefeld, Ca1519), 6.viii.2002, 2♂ 4♀; Mt. Robson Prov. Pk., hiking trail along Robson R. (53°02’06”N, 119°13’50”W) up to Kinney Lake (53°04’56”N, 119°11’05”W, 981m), swept on herbs & shrubs incl. Carex spp. , aspirated, (Universität Bielefeld, Ca1520), 6.viii.2002, 6♂ 8♀, all M.v.Tschirnhaus leg. (all ZSMC, all in ethanol); Pete Lake, 57°56’N 131°56’W, 4000’, 19.viii.1960, 1♀, R. Pilfrey leg.; Penticton, 1.vii.1967, 1♂, J. R. Vockeroth leg. (both CNCI); Prince George, 560–600 m, []. vii.1974, 1♀, N. L. H. Krauss leg. ( AMNH); Hart Highway, Bear Lake Camp, 72 km from Prince George, 24.vi.1978, 1♂, P. H. Arnaud, Jr. leg. ( CASC); Quesnel, Jon’s Spuds, 31.vii.1970, 1♀, G. J. Spencer leg. ( UBCZ); Robson, 18–26.v.1949, 1♂, 24.iv.1949, 2♀, 1–20.vii.1949, 4♂ 1♀ (1♂ genit. prep.), 7.vii.1950, 1♀, 13.vi.1952, 1♀, 23.vi.1952, 1♀, 4.viii.1952, 1♀, H. R. Foxlee leg. ( CNCI); Robson, 7.viii.1952, 1♀, 7.vi.1965, 1♀, 9.iv.1968, 1♂, H. R. Foxlee leg. ( UBCZ); Silver & Skagit Rd., 49°14’N 121°23’W to 49°08’N 121°15’W, 450– 600 m., clover & flowers, 22.vi.2000, 1♀, Goulet & Gillespie leg. ( DEBU 00278888); Terrace, marshy meadow, 11.vi.1960, 1♂, 31.vi.1960, 1♀, J. G. Chillcott leg., 13.vii.1960, 1♂ (with 3 orbitals on one side only), W. R. Richards leg., 17.vii.1960, 1♂, C. H. Mann leg.; Terrace, airport area, 2.viii.1960, 1♂, C. H. Mann leg.; 32 mi SW Terrace, open scrubby cut over area, 13.vii.1960, 1♂, J. G. Chillcott leg.; 50 mi SW Terrace, on and around wet cliff face, 9.vii.1960, 1♀, J. G. Chillcott leg.; 54 mi SW Terrace, 25.vii.1960, 2♂ 3♀, C. H. Mann leg.; Gagnon Rd., 6 mi W Terrace, 24.vi.1960, 1♂, G. E. Shewell leg., 29.vi.1960, 1♂, 9.vii.1960, 1♀, C. H. Mann leg.; as above but 220’, 20.vi.1960, 1♀, B. Heming leg.; Kleanza Cr., 14 mi E Terrace, 4.vii.1960, 1♂, C. H. Mann leg., 14.vii.1960, 5♂ 3♀, G. E. Shewell leg., 19.vii.1960, 1♀, W. R. Richards leg.; as above but wet scrub in cut over forest, 17.vi.1960, 1♂, J. G. Chillcott leg.; Shames, 18 mi SW Terrace, 23.vi.1960, 1♂ 3♀, C. H. Mann leg. (all CNCI); Silver Lake, Hope, 2.vii.1968, 2♀, W. W. Wirth leg. ( USNM); Williams L., 20.viii.1960, 2♂ 1♀, W. R. Richards leg. ( CNCI); Yoho National Park, 51°13’26”N 116°36’49”W, EMAN site 2, aspen, pan, 31.viii.–6.ix.1998, 1♂ 1♀, A. Duguay, W. Fitch, R. Longair & M. Whittaker leg. ( BDUC). Manitoba: 26 km SE Churchill, Twin Lakes burn site, 58.6173°N 93.8123°W, 38 m a.s.l., 1.viii.2010, 1♂ (Barcode of Life, Sample ID #10PROBE-12874) 2♀ (10PROBE-12876, 10PROBE-12877), J. Wang leg. ( BIOUG, in ethanol); Erickson, 4.viii.1979, 4♂ 1♀ (1♂ genit. prep.), 7.viii.1979, 1♂ 1♀, pans, 5.viii.1979, 1♂, 6.viii.1979, 2♀, D. H. Pengelly leg. ( DEBU); 13 km E Erickson, 31.vii.1983, 1♂ 2♀, K. N. Barber leg. ( DEBU, 1♀ genit. prep.); Ninette, 30.v.1958, 1♂, C. D. F. Miller leg.; Ninette, maple-elm floodplain community, 15.vii.1958, 1♂ 1♀, J. G. Chillcott leg.; Int[ernational] Peace Gardens, Turtle Mtn. For[est] Res[erve], 17.vii.1958, 1♂ 3♀, J. G. Chillcott leg. (all CNCI). New Brunswick: Doaktown, Hwy. 8, 7.viii.1971, 1♀, B. V. Peterson leg. ( CNCI). Newfoundland & Labrador: Gander, 10.vii.1961, 1♀, C. P. Alexander leg. ( USNM). Nova Scotia: Springfield, 6.viii.1958, 1♂ 1♀, J. R. Vockeroth leg. ( CNCI, 1♂ genit. prep.). Ontario: Abitibi Canyon, 49°53.54’N 81°34.09’W, sweeps, mostly Eurybia under Populus , 20.vii.2009, 7♂ 10♀, K. N. Barber leg.; Algonquin Park, s. of Shirley Lk., decid[uous], moose d[u]ng, 28.vii.–5.viii.1984, 1♀; as above but m[u]shr[oo]m t[ra]p., 5–11.viii.1984, 1♀, both K. Pendreigh leg. (all DEBU); Aubrey Falls Prov. Park, 77 km NNE Thessalon, 46°54.96’N 83°12.71’W, sweeping Clintonia , ferns, Diervilla in mixed forest, 5.vii.2010, 1♀, J. Roháček leg. ( SMOC, genit. prep.); Bruce Co., Dunks Bay, 45°14.8’N 81°38.1’W, sweeps, trailside veg. in mixed forest, 3.vii.1999, 1♂; Bruce Peninsula N. P., Cameron Lk. Rd., 45°12.5’N 81°33.5’W, sweeps, trailside veg., grasses, mixed forest, 4.vii.1998, 1♀, all K. N. Barber leg.; ~ 22 km SW Chapleau, Island Lake Biomass, jack pine forest (~40yr), pitfall traps (3C), 47°41.56’N 83°35.37’W, 25.vi.-10.vii.2012, 1♂; as above but (4C), 47°41.56’N 83°35.44’W, 10–23.vii.2012, 2♀; ~26kmSSE Chapleau, Island Lake Biomass, jack pine forest (~80yr), pitfall traps (1N), 47°38.23’N 83°14.78’W, 11–24.vii.2012, 1♀; as above but (3N), 47°38.20’N 83°14.68’W, 11–24.vii.2012, 1♀, 24.vii.–8.viii.2012, 2♂ 1♀ (1♂ 1♀ in copula), 8–20.viii.2012, 1♂, 20–29.viii.2012, 1♂; as above but (4N), 47°38.18’N 83°14.63’W, 26.vi.–11.vii.2012, 3♂ 1♀, 24.vii.–8.viii.2012, 2♂ 1♀, 8–20.viii.2012, 1♂, 20–29.viii.2012, 2♂; as above but (5N), 47°38.16’N 83°14.58’W, 11–24.vii.2012, 1♀, 24.vii.–8.viii.2012, 1♀, all L.Venier leg.; ~ 14 km W Dubreuilville, Hwy 519, 48°19.95’N 84°44.87’W, sweeps, Clintonia , Cornus , Aralia , Diervilla , Maianthemum , under Betula / Abies, 2.ix.2009, 1♂; Dubreilville [sic Dubreuilville], 48°21.05’N 84°33.84’W, sweeps, Diervilla , ferns, Clintonia , Cornus , Aralia , Eurybia , Vaccinium under Populus / Pinus , 2.ix.2009, 16♂ 23♀ (1♀ with 3 strong orbitals on one side), all K. N. Barber leg. (all DEBU); Dubreuilville, 48°21.05’N 84°33.84’W, sweeping Diervilla , ferns, Clintonia , Cornus , Aralia , Eurybia , Vaccinium under Populus / Pinus , 10.vii. 2010, 18♂ 27♀ (1♂ 1♀ in copula); Dubreuilville, 48°21.09’N 84°33.90’W, sweeping undergrowth Pinus / Populus forest, with Clintonia , Vaccinium , ferns, graminoids, 10.vii. 2010, 4♂ 5♀, all J. Roháček leg. (all SMOC); ~ 55 km NNW Elliot Lake, s. of Rocky Island Lake, 46°49.32’N 82°59.54’W, sweeps, mostly Athyrium filix-femina , 3.vii.2010, 3♂ 3♀, K. N. Barber leg. ( DEBU); as above but 455 m, sweeping, ferns [ Athyrium filix-femina ] at forest margin, 3.vii.2010, 7♂ 7♀, J. Roháček leg. ( SMOC); Fairbank P. Pk., Wa-shai-ga-mog Trail, 46°28.11’N 81°26.19’W, sweeps, Clintonia , ferns, Maianthemum , under Acer / Abies, 5.ix.2009, 2♂, K. N. Barber leg. ( DEBU 01502396, -397); Greenwater P. Pk., Green Trail, sweeps, Eurybia , Cornus , Clintonia , Diervilla , Aralia under Populus , 21.vii.2009, 49°11.74’N 81°16.82’W, 1♂ 5♀ ( DEBU 01502185-190), 49°11.73’N 81°16.76’W, 5♀ ( DEBU 01502207-211), 49°11.72’N 81°16.70’W, 2♀ ( DEBU 01502215, -216), 49°11.77’N 81°16.73’W, 8♂ 5♀ ( DEBU 0150221-233), 49°11.79’N 81°16.79’W, 2♂ 2♀ ( DEBU 0150237-240); Greenwater P. Pk., Sandbar Lake Trail, sweeps, Eurybia , Cornus , Clintonia , Diervilla , Aralia , fern under Populus , 21.vii.2009, 49°12.71’N 81°17.53’W, 1♀ ( DEBU 01502004), 49°12.76’N 81°17.47’W, 1♂ 2♀ ( DEBU 01502012-014), 49°12.78’N 81°17.44’W, 3♀ ( DEBU 015017-019), 49°12.85’N 81°17.42’W, 9♂ 14♀ ( DEBU 01502043-065), 49°13.03’N 81°17.43’W, 2♂ 3♀ ( DEBU 01502071-075); Greenwater P. Pk., Sunset Trail, 49°11.26’N 81°16.54’W, sweeps, Eurybia , Cornus , Diervilla under Populus , 22.vii.2009, 1♀ ( DEBU 01502285), all K. N. Barber leg. (all DEBU); 7 mi E Griffith, 8.vi.1985, 1♂, 2.ix.1985, 1♂, B. E. Cooper leg. ( CNCI); Haileybury, 12.viii.1947, 2♂ 2♀, G. S. Walley leg. ( CNCI, 1♂ with 3 strong orbitals both sides); n. Hurkett, Black Sturgeon Rd., [various Site/ Trap data], mixed forest, pitfall trap, km.46.3, 49°11’15”N 88°42’30”W, Stand 1, 23.viii.–8.ix.1993, 46♂ 44♀, K. N. Barber leg. (44♂ 42♀ DEBU, 2♂ 2♀ SMOC); as above but km.56.6, 49°14’03”N 88°45’30”W, Stand 2, 23.viii.–8.ix.1993, 23♂ 34♀; as above but km.56.6, 49°11’15”N 88°42’30”W, Stand 3, 23.viii.–8.ix.1993, 2♂ 7♀, all K. N. Barber leg. (all DEBU); Iroquois Falls, Populus-Picea wood-rich undergrowth, 19.vi.1987, 1♀, 30.vi.1987, 2♂, J. R. Vockeroth leg. ( CNCI); Iroquois Falls region ( SLAM 2007), ~ 48.78°N 80.25°W, pitfall traps, deciduous forest, 14–21.viii.2007, 4♂ 1♀, 15–22.viii.2007, 9♂ 2♀, L. Venier leg. ( DEBU); Kearney, 26.vii.1911, 1♀, M. C. Van Duzee leg. ( CASC); Kelly Lake, 26.vii.1933, 1♂, Parish leg. ( USNM); Kettle Lakes P. Pk., Tamarack Trail, sweeps, Cornus , Clintonia , Eurybia , Diervilla under Populus , 22.vii.2009, 48°34.49’N 80°53.19’W, 4♂ 6♀ ( DEBU 0150287-296), 48°34.45’N 80°53.10’W, 5♀ ( DEBU 0150298-302); as above but Kettle Trail, sweeps, Cornus , Clintonia , Eurybia , Diervilla , Aralia under Betula , 22.vii.2009, 48°34.53’N 80°52.78’W, 4♀ ( DEBU 0150305-308), 48°34.45’N 80°52.74’W, 8♂ 7♀ ( DEBU 0150313-327), all K. N. Barber (all DEBU); Kirkland L[ake], 15.viii.1957, 2♂, D. Beneway leg. ( SEMC); Kirkland Lake, 24.vi.1980, 1♀, Joanne Cashaback leg.; Killarney P. Pk., 18.viii.1978, 1♂, W. A. Attwater leg. (both DEBU); Lake Superior P. Pk., Crescent Lk. Trail, 47°16.73’N 84°33.12’W, sweeps, Clintonia , ferns, Aralia , Maianthemum , under Acer / Betula , 2.ix.2009, 1♀ ( DEBU 01502363); as above but 47°16.75’N 84°33.19’W, sweeps, Clintonia , ferns, Aralia , Acer , under Acer , 2.ix.2009, 1♀ ( DEBU 01502367), both K. N. Barber leg. (both DEBU); Lake Superior Prov. Park Crescent Lake Trail, 47°16.81’N 84°33.23’W, sweeping, mostly graminoids under Betula / Acer , 9.vii.2010, 1♀, J. Roháček leg. ( SMOC); Lake Superior P. Pk., Fenton-Treeby trail, 47°51.19’N 84°53.01’W, sweeps, Clintonia , Aralia , Rubus , Cornus , ferns, under Alnus / Acer , 2.ix.2009, 1♀ ( DEBU 01502340), 13.vi.2010, 2♂ 3♀ ( DEBU 01502464-68); Lake Superior P. Pk., Trappers Trail, 47°32.53’N 84°48.50’W, sweeps, trailside sedges, 13.vi.2010, 1♂ ( DEBU 01502485), all K. N. Barber leg. (all DEBU); Marmora, 5.vi.1952, 1♂, J. R. Vockeroth leg.; Maynooth, at light, 7.vii.1951, 2♀, J. F. McAlpine leg. (all CNCI); ~ 20 km E Nipigon, Hwy. #17, rest area, 48°58.00’N 87°59.09’W, sweeps, Aster [ Eurybia ], Rubus , Aralia , Diervilla , 31.vii.2008, 109♂ 63♀, K. N. Barber leg. (5♂ 3♀ each AMNH, BDUC, CASC, CMNH, CNCI, EMUS, INHS, LEMQ, MCZC, PMAE, RBCM, UBCZ, USNM, SMOC 1♂ genit. prep., 39♂ 21♀, DEBU, 1♂ wing removed, 1♀ with 3 strong orbitals on one side and short 3 rd ors on other, 2♂ 3♀ genit. prep.); Ogoki, 15.vii.1952, 1♂, J. B. Wallis leg.; One Sided Lake, 20.vi.1960, 1♂ 1♀, S. M. Clark leg., 27.vi.1960, 1♀, Kelton & Whitney leg.; Orillia, 15.vii.1923, 1♂, C. H. Curran leg. (all CNCI); Ottawa, 2.vii.1912, 1♀, Beaulieu leg., 27.vii.1925, 2♀, C. H. Curran leg.; Ottawa, 17.vii.1955, 1♀, at light, 26.vii.1951, 1♂, newly cut Manitoba maple, 28.vi.1952, 1♀, bleeding elm stump, 21.vi.1955, 1♀, J. F. McAlpine; Ottawa, 24.vi.1958, 1♀, 25.vi.1964, 1♂, 29.vi.1964, 1♀, 22.vi.1965, 1♀, 26.vii.1965, 1♀, 13.viii.1965, 1♀, J. R. Vockeroth leg.; Ottawa, at light during heavy rain, 26.vi.1964, 1♀, [coll.?] (all CNCI); Otter Rapids, 50°11.08’N 81°38.37’W, sweeps, Eurybia , Equisetum under Populus , 20.vii.2009, 13♂ 13♀, K. N. Barber leg. ( DEBU, 1♂ genit. prep.); Pukaskwa N. P., Coastal Trail Hattie Cove—Playter Harbour, sweep, 21.vii.2001, 1♂ ( DEBU 00183060); Thunder Bay District, Pukaskwa N. P., Coastal Trail Playter Harbour—White River, sweep, 21.vii.2001, 1♂ 5♀ ( DEBU 00183735, -3737, -4042, -4057, - 4075, 4082), all M. Buck leg. (all DEBU); Pukaskwa N. P., Site APUK12 Trap 5, 48°24.1’N 85°51.4’W, pitfall trap, mixedwood forest, 12.vi.–11.vii.2001, 1♀, J. Pearce & L. Venier leg.; Rushbrook Lake, UTM17T269770, SP2, plot 25, []. vii.1994, 1♀, A. P. Applejohn leg. ( DEBU); Rushbrook Lake, Camp 8, Stand 2, Site 4, 46°43.8’N 81°56.6’W, 12-unit Lindgren trap, Trap 28, alpha pinene bait, 29.vi.–14.vii.1999, 1♀, Trap 29, ethanol bait, 28.vii.–12.viii.1999, 2♀, K. Nystrom leg. (all DEBU); S[ault] S[te.] Marie, Baseline Rd., 46°31.40’N 84°24.40’W, sweeps, Aster [ Doellingeria ], Rubus , Equisetum , Carex , ferns, under aspen, 8.vii.2005, 1♀, K. N. Barber leg. ( DEBU); S[ault] S[te.] Marie, Birchwood Pk., mixed forest, 28.vi.1986, 1♀, 30.vi.1986, 1♀, 1.vii.1986, 1♂ 1♀, 6.vii.1986, 1♂ 1♀; as above but Birchwood Pk., 46°30.7’N 84°15.6’W, sweeps, mostly fern, Aralia , Impatiens , dewberry, grass under Betula / Acer , 30.viii.1997, 1♀, 1.ix.1997, 1♂ 1♀ (1♂ genit. prep.); as above but sweeps, mostly Impatiens , under Betula / Acer , 19.vi.1998, 1♀, 20.vi.1998, 1♂; as above but sweeps, Impatiens , under Betula / Acer , 27.vi.1998, 1♂ 1♀, 25.vi.1999, 1♀; as above but sweeps, mostly Aralia , fern, Impatiens , dewberry, grass, under Betula / Acer , 25.vi.1999, 1♀; as above but sweeps, graminoids, Impatiens , Aster [ Doellingeria ], ferns, under Betula / Acer , 18.ix.2004, 1♂; as above but 46°30.75’N 84°15.62’W, sweeps, Rubus , Aralia , graminoids, ferns, Aster [ Eurybia ], under Betula / Acer , 18.ix.2004, 1♂; as above but 46°30.67’N 84°15.63’W, sweeps, Rubus , Aralia , graminoids, ferns, under Betula / Acer , 25.viii.2012, 1♂, all K. N. Barber leg. (all DEBU); S[ault] S[te.] Marie, Bristol Pl[ace], 46°30.8’N 84°16.4’W, at MV lights in yard, 7.vii.2000, 1♂, 10.vii.2000, 1♀; as above but Bristol Pl[ace] Pk., 46°30.8’N 84°16.6’W, sweeps, Impatiens under Betula / Populus , 9.vii.1998, 1♀; as above but 46°30.77’N 84°16.66’W, sweeps, Impatiens , Clematis , Equisetum , Rubus , ferns, Phalaris , 11.vii.2008, 1♀, all K. N. Barber leg. (all DEBU); S[ault] S[te.] Marie, Finn Hill, 46°31.9’N 84°17.6’W, sweeps, Aster [ Eurybia ], Rubus , Ribes , ferns, graminoids, 7.vii.2002, 1♀; as above but 46°31.57’N 84°17.41’W, sweeps, Aster [ Eurybia ], ferns, graminoids under canopy, 19.ix.2004, 1♀; as above but 46°31.63’N 84°17.43’W, sweeps, Impatiens , ferns, Carex gynandra , 8.vii.2006, 1♀, all K. N. Barber (all DEBU); S[ault] S[te.] Marie, Sault Coll[ege] Outdoor Lab, 46°32.1’N 84°18.2’W, sweeps, mostly Impatiens under Acer / Betula , 18.vi.1998, 1♀, K. N. Barber leg. ( DEBU); ~ 18 km NNE Searchmont, Goulais River WS [watershed], ~mi.15 Whitman Dam Rd., 46°55.3’N 83°56.4’W, sweeps under mixed canopy, 30.vii.1999, 2♂ 4♀; ~ 13 km NNE Searchmont, Whitman Dam Road, km.17.2, 46°53.13’N 83°59.37’W, sweeps, Clintonia , Taxus , ferns, Aralia , Trientalis , Maianthemum , Streptopus , under Acer , 23.viii.2009, 1♀; Icewater Creek WS [watershed] [~14.7 km N Searchmont], 46°53.7’N 84°03.4’W, sweeps, trailside sedges / ferns, mixed forest, 7.vii.1998, 1♀; as above but sweeps, trailside sedges, ferns, grasses, 10.vii.1998, 4♂ 8♀ (2♀ genit. prep.); as above but sweeps, Thalictrum , Eupatorium [ Eutrochium ], fern in mixed forest, 10.vii.1998, 1♂; as above but 46°54.0’N 84°03.4’W, sweeps, trailside ferns, graminoids, mixed forest, 5.viii.2006, 2♂ 2♀, all K. N. Barber (all DEBU); as above but ~12.7 km NNE Searchmont, mi.10.5 Whitman Dam Rd., riparian meadow– alder thicket, Malaise, 27.viii.–8.ix.1986, 1♀, 8–29.ix.1986, 1♀, [K. N. Barber leg.] ( DEBU); as above but 12.7 km NNE Searchmont, mi.10.5 Whitman Dam Rd., mixed forest, 13.vi.1986, 1♀, 1.vii.1986, 1♀; as above but ~14.7 km N Searchmont, 46°53.77’N 84°03.36’W, sweeps, Clintonia , Maianthemum , ferns, Cornus , under Acer / Picea , 11.viii.2009, 1♀, all K. N. Barber leg. (all DEBU); Serpent River, Hwy. 17 picnic area, 46°12.60’N 82°30.83’W, sweeps, Clintonia , Smilacina [ Maianthemum ], ferns, Trientalis , under Acer / Betula , 5.ix.2009, 1♂; Thunder Bay District, Sleeping Giant Prov. Pk., Kabeyun Trail, Perry Bay —Tee Harbour, 12.vii.2002, 1♂ ( DEBU 00199143); as above but Sawbill Lk. Trail, 48°21’47”N 88°47’53”W, 9–14.vii.2002, 1♀ ( DEBU 00199159); Sleeping Giant Prov. Pk., Marie Louise Lk. Campground, 48°21’N 88°50’W, forest trail, white pans, 13.vii.2002, 3♀ ( DEBU 00223823, -841, -985), all M. Buck leg. (all DEBU); Shakwa Lake, Ouellette Twp., plot 2A, []. viii.1996, 1♂, plot 2B D3, 21.vii.1996, 1♀, plot 3, 21.x.1995, 1♂, plot 7, 21.viii.1996, 1♂, plot 11, [no date], 2♂ 1♀, plot 13 D2, 21.vii.1996, 1♀, plot 25 D2, 21.vii.1995, 1♀, A. Applejohn leg. ( DEBU); ~ 92 km NNE Thessalon, Mountain Ash Lake, 47°03.53’N 83°12.56’W, sweeps, Clintonia , Eurybia , ferns, Diervilla under Betula / Abies, 4.vii.2010, 1♀; Hwy# 129, 44 km N, jct #556 [~ 115 km N Thessalon], 47°12.0’N 83°10.3’W, sweeps, veg. under Populus / Betula , 5.viii.1999, 1♀, all K. N. Barber leg. (all DEBU); Thunder Bay, 28.vii.1970, 1♀, 30.vii.1970, 1♂, 15.viii.1970, 1♂, K. J. G. Deacon ( DEBU); Turtle River, plot 44 II, []. vii.1994, 2♀, A. P. Applejohn leg. ( DEBU); Waubamick, []. vii.1915, 1♀, H. S. Parish leg. ( USNM, genit. prep.); White Otter Lake, SP2, plot 43, []. vii.1994, 1♂, UTM15T882377, plot 42, []. vii.1994, 1♂, A. Applejohn leg. ( DEBU); 27 km SSW White River, B1 S1 UD, 48°21.1’N 85°20.6’W, boreal mixedwood, opaque sticky trap, 7–27.viii.2002, 1♀; 38 km SSW White River, B5 S2 IO, 48°15.1’N 85°23.7’W, boreal mixedwood, opaque sticky trap, 17.vii.–8.viii.2002, 1♀, both S. B. Holmes leg. (both DEBU); 40 km SSW White River, boreal mixedwood, multi-colour sticky trap, B6 S3 #9, 48°14.05’N 85°21.99’W, 10–23.vii.2003, 4♂, B6 S3 #12, 48°14.06’N 85°21.97’W, 10–23.vii.2003, 1♀, B6 S9 #19, 48°14.25’N 85°22.14’W, 10–23.vii.2003, 1♀; as above but Malaise trap, B6 S3A, 48°14.06’N 85°21.97’W, 11–24.vi.2003, 1♀, 7–22.vii.2003, 1♀, B6 S3C, 48°14.05’N 85°21.98’W, 14–24.vi.2003, 1♀, 24.vi.–7.vii.2003, 1♀, 7–22.vii.2003, 1♂, B6 S4, 48°14.13’N 85°22.01’W, 24.vi.–7.vii.2003, 2♀, B6 S9, 48°14.23’N 85°22.15’W, 11–24.vi.2003, 1♀, 24.vi.–7.vii.2003, 1♀, all K. N. Barber leg. (all DEBU); as above but B6 S4–S9, 48°14.2’N 85°22.1’W, trailside sweeps, 8.vii.2003, 1♀, B. Benoit leg. ( DEBU); as above but B6 S4–S9, 48°14.2’N 85°22.1’W, sweeps, Aster [ Doellingeria ], Aralia , Cornus , 9.vii.2003, 10♂ 10♀ (incl. 1♂ 1♀ in copula); as above but B6 S1, 48°13.95’N 85°22.19’W, sweeps, mostly Carex , 23.vii.2003, 1♂ 2♀; as above but B6 S1, 48°13.95’N 85°22.20’W, sweeps, Calamagrostis canadensis , 23.vii.2003, 1♂ 4♀; as above but sweeps, Aster [ Doellingeria ], Aralia , ferns, 23.vii.2003, near B6 S1, 48°13.97’N 85°22.28’W, 2♂ 3♀, near B6 S9, 48°14.23’N 85°22.13’W, 4♂ 8♀, all K. N. Barber leg. (all DEBU); ~ 17 km SW White River, Site R1A05 Trap 7, 48°28.7’N 85°26.8’W, pitfall trap, 0-5yr jackpine regen., 5.vii.–10.viii.2001, 1♂; ~ 35 km W White River, Site FOR008 Trap 7, 48°30.8’N 85°43.8’W, pitfall trap, mixedwood forest, 25.vi.–21.vii.2001, 1♂, both J. Pearce & L. Venier leg. (both DEBU). Quebec: Beechgrove, 45°39’N 76°8’W, 29.vii.1962, 2♂, J. R. Vockeroth leg.; Breckenridge, 11.vi.1959, 1♀, C. H. Mann leg.; Cottage Beaulieu, 16.vii.1906, 1♂, Beaulieu leg. (all CNCI); Gaspé, ZEC [Zone d’Exploitation Contrôlée] York-Baillargeon, 48°49’N 64°52’W, forest edge near Lac Pauline, sweep, 26.vii.2000, 1♂, H. Varady-Szabo leg. ( LEMQ 0040164); Gaspesie, near Routhierville, 48°10.9’N 67°08.8’W, sw[ee]p picnic area, 4.viii.2001, 3♂, S. Boucher leg. ( LEMQ 0040161-63, 1♂ genit. prep.); Lac Crescence, Kam[ouraska] Co., 10.viii.1957, 1♂, W. R. M. Mason leg.; 6 mi SE Lac Megantic, 22–24.vi.1982, 1♂, H. J. Teskey leg.; Lac Phillipe, 31.vii.1955, 40°37’N 76°W, 1♀, J. R. Vockeroth leg.; Lac Ste. Marie, 27.vii.1936, 1♀, F. A. Urquhart leg.; Laniel, 21.vi.1944, 1♀, 1.vii.1944, 1♀, 3.vii.1944, 1♀, A. R. Brooks leg., 17–18.vi.1963, 1♀, W. Gagne leg. (all CNCI); Messines, 10.vii.1947, 1♀, [no collector]; Mistassini Post, 21.vii.1956, 1♀, J. R. Lonsway leg.; Mt. Orford, 14.vii.1936, 1♀, G. E. Shewell leg. (all CNCI); Old Chelsea, 11.vi.1959, 1♀, 21.vi.1959, 1♀, 13.vi.1961, 1♀, 4.vi.1964, 1♀, 15.vi.1964, 1♂, 3.vi.1968, 1♀, J. R. Vockeroth leg. ( CNCI); Old Chelsea, Summit King Mt., 1150’, 21.vi.1959, 1♂, 18.vii.1961, 1♂, 25.vi.1962, 2♀, 2.vi.1964, 1♂, 8.vi.1964, 1♂, 15.vi.1964, 1♂ 2♀, 16.vi.1971, 1♂ 1♀, J. R. Vockeroth leg. ( CNCI); Percé, Coin-du-Banc, Rivière du Portage, sweep vegetation, 5.viii.2001, 1♀, H. Varady-Szabo leg. ( LEMQ 0040167); Wakefield, 26.vi.1946, 3♂ 2♀, 9.vii.1946, 1♂, G. E. Shewell leg., 9.vii.1946, 2♂ 3♀, A. R. Brooks leg. ( CNCI). Saskatchewan: Christopher L., 27.viii.1945, 1♂, A. R. Brooks leg. ( CNCI); Kenosee, 7.vi.1958, 1♀, A. R. Brooks leg. ( CNCI); Saskatoon, 9.vii.1957, 1♂, A. R. Brooks leg. (all CNCI); ~ 13 km S Saskatoon, Beaver Creek Cons[ervation] Area, 51°58.6’N 106°43.0’W, sweeps, mostly grasses under Betula / Populus , 12.vii.1999, 4♂ 2♀, 17.vii.1999, 1♂; as above but outside Beaver Creek Cons[ervation] Area, 17.vii.1999, 4♂ 9♀ (1♀ with supernumerary veins, 1♂ genit. prep.); ~ 10 km WSW Saskatoon, Poplar Bluffs Cons. Area, 52°01.7’N 106°43.0’W, sweeps, low veg. under Populus , 19.vii.1999, 1♂ 1♀, all K. N. Barber leg. (all DEBU); Scout Lake, 49°20’N 106°0’W, 17.vi.1955, 1♀ Sturgis, 51°56’N 102°32’W, 1.vii.1955, 1♂ 1♀, all J. R. Vockeroth leg. (all CNCI). Yukon Territory: Carcross, Lake Bennett, pan trap in dunes behind beach, 30.vi.–5.vii.1997, 1♀ ( LEMQ 0040170); Carcross, Govt. Campground, 60°10.5’N 134°42.1’W, sweep vegetation at campsite, 20.vii.1998, 3♀ ( LEMQ 0040179-81); 1 km N Carcross, 60°11.2’N 134°42.3’W, pan traps in pine forest, 9–13.vii.1998, 2♂ ( LEMQ 0040186, -87, 1♂ genit. prep), all T. A. Wheeler leg. (all LEMQ); Moose Ck. Campground, aspen, mush[room] vac[uum] 2, 3.vii.1985, 2♀, S. Marshall leg. ( DEBU); Yukon River Campground, opposite Dawson City, 6.vii.1978, 1♂, P. H. Arnaud, Jr. leg. ( CASC). UNITED STATES: Alaska: Fairbanks, 135 m, 10.vii.1978, 1♂, P. H. Arnaud, Jr. leg. ( CASC); Fairbanks, [?]. viii.1960, 5♂, M. R. W. Wheeler & L. Throckmorton leg. ( AMNH, 1♂ genit. prep.); Kenai Peninsula Borough, ~1/ 3 mi NW of Marathon Rd. and ~ 2 mi SE of Konovalof Lk., NW 1/4 of section 6, Long Term Ecological Monitoring Program 3134, sweep net sample, 25.vi.2006, 1♂, T. Burke leg. ( KNWR, ID: 5453); Kenai Peninsula Borough, Swanson River Oil Field, mixed forest and alders at N shore of 310 L., SE corner of section 3, Long Term Ecological Monitoring Program 3076, sweep net sample, 25.vi.2006, 1♀, A. Wu leg. ( KNWR, ID: 5958); Richardson Hwy., mi.313, FIT in roadside alders, 16–19.vii.1985, 1♂, S. A. Marshall leg. ( DEBU); Shaw Creek, mi.289, Rich[ardson] Hwy, 11.vii.1951, 1♀, Mason & McGillis leg. ( CNCI). Colorado: Gothie, Gunnison Co., 9500’, 30.vii.1961, 1♂ 1♀, J. G. Chillcott leg. ( CNCI); Teller Co., Sanborn Ranch, S of Florissant, The Nature Place, 23.vii.2005, 1♂; Sanborn Ranch, 3.5 mi S Florissant, swept from aspen grove nr. girls camp, 17.vii.2000, 1♂ 1♀, all B. A. Foote leg. (all CMNH); Larimer Co., Sheep Crk. near jct. Buckhorn Crk., 13.vii.1995, 1♂, S. Gitzgerald & A. Foley leg. ( CSUC). Idaho: Chatcolet, []. viii.1915, 1♂ 1♀, A. L. Melander leg. ( USNM); Lake Coeur d’Alene, 15.vii.1926, 1♂ 1♀, E. H. Nast leg. ( CASC); Latah Co., 7 mi E Moscow, 20.vi.1980, 1♀, N. E. Woodley leg.; Priest Lake, 1.viii.1916, 1♂, A. L. Melander leg.; Moscow Mtn., 25.vi.1968, 1♀, W. W. Wirth leg. (all USNM). Michigan: Ironwood, 46°27.9’N 90°10.1’W, sweeps, low veg. under Populus / Pinus , 22.vii.1999, 1♂, K. N. Barber leg. ( DEBU); Isle Royale, 3–7.viii.1936, 1♂, R. R. Dreisbach leg., 2♀, C. Sabrosky leg. ( USNM, 1♀ genit. prep.); Keweenaw Co., Isle Royale, 7.vii.1938, 3♀, G. Steyskal leg. ( USNM, 1♀ genit. prep.). Minnesota: Eaglesnest, 5.vii.1957, 1♀, W. V. Balduf leg. ( INHS, 40,130). Montana: 1.0 mi W Big Fork, 29.vi.1967, 1♀; 15.0 mi NE Polson, 4.vii.1966, 1♀, both B. A. Foote leg. (both USNM); 9.0 mi N Swan Lake, 19.vii.1966, 2♂; 33.0 mi N West Glacier, 5.vii.1966, 2♀, all K. Valley leg. (all USNM). New Hampshire: Benton, 6.vii.1931, 1♂, A. L. Melander leg. ( USNM); Bretton Woods, 25.vi.[no year], 1♀, C. W. Johnson leg. ( MCZC); Franconia N[o]tch, 8.vii.1931, 2♀, A. L. Melander leg. ( USNM); Glen House, 17.vii.[no year], 1♂ 1♀, C. W. Johnson leg. ( MCZC); Mt. Washington, [no date], 1♀, Mrs. A. T. Slosson leg. ( AMNH Ac.26226, genit. prep.); as above but 1♀, Mrs. Slosson ( USNM); Mt. Washington, Summit Flats, 5900–6200’, 29.viii.1954, 1♂, Becker, Munroe, Mason leg. ( CNCI); “N.H.”, [no date], 1♂ 1♀, Osten Sacken leg. ( MCZC, both genit. prep.). New Mexico: Rio Arriba Co., Hwy. 17 ca. 8 mi NNE of Chama & 0.5 mi S Colorado b[oun]d[ar]y, 9000’, 12.viii.1965, 1♀, H. B. Leech leg. ( CASC). New York: Lake Placid, 2000’, 30.vii.1961, 1♀, J. R. Vockeroth leg. ( CNCI, genit. prep.). Pennsylvania: Dubois, 3.ix.1927, 2♂, A. L. Melander leg. ( USNM). Utah: Cache Co., Blacksmith Fk. Cyn., 19.vi.–8.vii.1985, 1♀; Cache Co., Cowley Canyon, 3–10.viii.1989, 1♀; Cache Co., Logan Canyon, 30.viii.1964, 1♂; Cache Co., Logan Cyn., Twin Cr., 1–8.vii.1988, 1♀, 8–15.vii.1988, 1♂, 15–22.vii.1988, 3♂ 4♀, 22–29.vii.1988, 6♂ 6♀ (1♂ genit. prep.), 29.vii.–5.viii.1988, 1♀ all W. J. Hanson leg. (all EMUS); Cache Co., W Hodges Canyon, 8–21.vii.1978, 1♀, 8–11.viii.1978, 1♀, Knowlton & Hanson leg.; Cache Co., Tony Grove Jct., 21–28.ix.1983, 1♂, [collector?]; Grand Co., LaSal Mtns., Warner C[am]p, 9500’, 21.vii.1968, 1♀, W. J. Hanson leg.; Summit Co., Woodland, 31.vii.1972, 1♂, W. J. Hanson leg.; Utah Co., Mapleton, Malaise trap, 25.vi.–6.vii.1985, 1♀, 6–16.vii.1985, 1♂, [collector?]; Utah Co., Provo, Malaise trap, 19–27.vii.1985, 1♂, [collector?]; Wasatch Co., Daniel Cn., 8.viii.1965, 1♀, G. F. Knowlton leg. (all EMUS). Vermont: Springfield, 15.vii.1931, 1♂, A. L. Melander leg. ( USNM). Washington: Clallam Co., Sequim, 2.viii.1951, 1♂, M. R. Wheeler leg. ( AMNH); Lewis Co., Big Creek Campground, 4.4 km SE Ashford, 550 m, 2.vii.1974, 2♂, P. H. Arnaud, Jr. leg. ( CASC); Orcas Isl[and], Cascade Lake, 17.viii.1925, 1♂, A. L. Melander leg. ( USNM). Wyoming: Teton Co., Grand Teton National Park, Teton Science School near Kelly, 24–25.vii.1982, 1♀, S. C. Williams leg. ( CASC); Washakie Co., 12.5 km ESE Ten Sleep, Tensleep Pres[erve], TNC [The Nature Conservancy], C[an]y[o]n Cr[ee]k, 25.vi.1996, 1♂, K. B. Miller leg. ( CSUC, genit. prep.).

Other material not designated as paratypes (damaged):

CANADA: Alberta: Dunvegan, N side Peace River, pan traps in grasses, 25.vii.–1.viii.1995, 1♂, S. Boucher leg. ( LEMQ 0040276, missing abdomen). British Columbia: Glacier National Park, ca. 1.6 km N Glacier, 14.vii.1974, 1♀, P. H. Arnaud, Jr. leg. ( CASC, missing abdomen). Ontario: Dubreuilville, 48°21.05’N 84°33.84’W, sweeping Diervilla , ferns, Clintonia , Cornus , Aralia , Eurybia , Vaccinium under Populus / Pinus , 10.vii. 2010, 3♂ 3♀, J. Roháček leg. ( SMOC, partly used for DNA analysis); Thunder Bay, 25.vii.1970, 1♂, K. J. G. Deacon leg. ( DEBU, missing head & wings, genit. prep.). UNITED STATES: Utah: Cache Co., Logan Can., Twin Cr., 15–22.vii.1988, 1♂, W. J. Hanson leg. ( EMUS, very greasy and dirty).

Etymology: The name “duplex” (= double, from Latin) was originally used by G. E. Shewell to label several specimens in CNCI. It refers to the laterally bicolourous thorax of the species.

Description: M a l e. Total body length 2.10–2.70 mm; body bicolourous ( Figs 3 , 100 ), dark brown and yellow, sparsely grey microtomentose and distinctly shining. Head yellow and dark brown as in A. acuticuspis but generally lighter, slightly higher than long, rounded anteriorly in profile ( Fig. 3 ). Occiput dorsomedially concave, blackish brown except for ochreous ventral marginal area, sparsely grey microtomentose and shining. Frons largely dull and yellow, only frontal and ocellar triangles brown and shining despite sparse grey microtomentum. Frontal triangle with anterior corner tapered, acute and yellowish. Orbit largely yellow and silvery white microtomentose, only in front of vti more or less darkened, ochreous to pale brown; a silvery white microtomentose stripe/spot between posterior part of orbit and frontal triangle dilated on posterior corner of frontal triangle and anteriorly connected with similarly microtomentose orbit but silver microtomentum on marginal line in anterior half of frontal triangle reduced, poorly visible. Rest of frons yellow (darker posteriorly), without microtomentum, dull. Frontal triangle longer than that of A. acuticuspis , reaching anterior fourth of frons. Frontal lunule as in close relatives. Face narrow, medially concave, almost white, whitish microtomentose and dull; border line separating it from parafacialia dark yellow. Parafacialia and gena also white, densely silvery white microtomentose; ventral marginal stripe of gena yellow to ochreous and posteriorly fine. Postgena white anteriorly, yellow posteriorly. Mouthparts yellowish white, with white palpus and dirty yellow clypeus and prementum. Cephalic chaetotaxy generally similar to that of A. acuticuspis but differing as follows: vti longest of cephalic setae, usually slightly longer than oc; 2 ors but anterior distinctly shorter (less than half) than posterior; 2 microsetulae in front of the anterior ors; 2 (rarely 3) pairs of medial microsetulae in front of frontal triangle; 1 proclinate setula behind vte; postocular setulae (8–9) relatively short, in single row; 1 fine but relatively long vi (slightly shorter than posterior ors); subvibrissa variable, distinctly thinner and shorter (two-thirds or less) than vi, sometimes reduced and only slightly longer than anterior peristomal setula; 6–8 fine peristomal setulae. Palpus very slender, whitish, with 1 fine dark preapical seta (subequal but finer than subvibrissa) and about 10 whitish ventral setulae. Eye large, suboval, with longest diameter slightly oblique, about 1.3 times as long as shortest. Genal shortest height about 0.10 times as long as shortest eye diameter. Antenna with scape and pedicel yellow to pale yellow; 1st flagellomere almost white, with short white pilosity. Arista dark brown, with paler and thickened basal segment, about 2.0 times as long as antenna, with cilia as short as those on apex of 1st flagellomere but brown.

Thorax slightly narrower than head, bicolourous: mesonotum and scutellum dark brown, smaller dorsal part of pleura brown to pale brown, larger ventral part of pleura ochreous (dorsally) to yellow (ventrally); also notopleural area usually yellow and humeral lobe pale brown to ochreous ( Figs 3 , 100 ). Extent of yellow pleural part variable, always reaching at least to middle of mesopleuron, sometimes extended up to dorsal margin of mesopleuron leaving only propleuron, metapleuron and subscutellum brown. Thoracic chaetotaxy: 1 hu (slightly longer than posterior npl); 2 npl (anterior long, subequal or slightly shorter than prs, posterior short); 1 long prs (usually shorter than anterior dc); 1 long sa (as long as prs); 1 pa (shorter than sa); 2 very long postsutural dc (posterior longest of thoracic setae, anterior slightly longer than prs) and 3–5 dc microsetae (hindmost longer than others) in front of them; 2–3 (usually incomplete) medial pairs of ac microsetae; 2 sc, laterobasal sometimes longer than hu, apical long and robust but usually shorter than posterior dc; 1 minute ppl; 2 long stpl, anterior shorter and weaker, posterior somewhat shorter than prs, 3–5 upcurved dark setulae below them and regularly 1 additional setula in front of anterior stpl; ventral part of sternopleuron with 4 longer pale setae. Scutellum rounded triangular, slightly convex dorsally. Legs coloured as in A. acuticuspis . f 1 with ctenidial spine rather variable, slightly to distinctly longer than maximum width of t 1, and with a long posteroventral row of long fine setae. f 3 with usual row of posteroventral setae, 8–9 of which in distal two-fifths short and thickened; t 2 with distinctly short (only slightly longer than maximum width of tibia) ventroapical seta; fore and hind basitarsi with 2 longer pale hair-like proximoventral setulae; mid basitarsus with 1 longer but dark setula. f 2, t 1 and t 3 simply setulose. Wing ( Fig. 169 ) very similar to that of A. acuticuspis including colour, shape and venation only differing by discal (dm) cell with rm situated in the middle of dm cell or even beyond it. Wing measurements: length 2.24–2.78 mm, width 0.69–0.93 mm, Cs 3: Cs 4 = 1.13–1.43, rm\dm-cu: dm-cu = 1.64–2.50. Haltere pale yellow, with whitish knob.

Abdomen with terga dark brown, sterna brown ( Fig. 3 ), sparsely pale grey microtomentose but distinctly shining. T1 (usually paler) and T2 almost separate, only laterally partly fused. T3–T5 subequal, broad, bent onto ventral side of abdomen. Preabdominal sterna relatively large and broad, well sclerotized and becoming distinctly wider posteriorly; S1 as in A. acuticuspis ; S2 slightly shorter than wide, S3 and S4 subequal in length, broad and distinctly transverse but S4 distinctly wider; S5 largest, widest and strongly transverse, posteromedially distinctly emarginate. T6 short and transversely band-like, bare, brown but submedially narrowly desclerotized and unpigmented. S6–S8 dorsally fused together. S6 and S7 as in A. acuticuspis but each with 2 short setae; S8 long (as long as epandrium), sparsely setose in posterior half, largely without microtomentum and glossy as also are basal and dorsomedial parts of epandrium.

Genitalia generally formed as those of A. acuticuspis and A. bivittata . Epandrium ( Figs 106, 107 ) blackish brown, as wide as that of A. acuticuspis but longer (almost hemispherical), with 1–2 dorsolateral setae long and robust and also 1–2 setae somewhat longer than others; anal fissure (dorsally) relatively small and narrow and often somewhat asymmetrical, with distinct lateral notch (cf. Fig. 107 ). Cercus relatively large, slightly flattened, palepigmented and finely setose, with a set of 4–6 apical and subapical long setae. Medandrium ( Fig. 106 ) about as wide as that of A. acuticuspis and similarly formed as in the latter species including well-developed dorsolateral corners but with reduced posteromedial keel. Gonostylus ( Figs 106, 107, 112 ) ochreous to yellow, markedly different from that of both A. acuticuspis and A. bivittata , small, relatively narrow and posteriorly bent in lateral view, with broadly rounded apex, somewhat also bent medially ( Fig. 106 ), with micropubescence restricted to basal half of outer side ( Fig. 112 ) and with most of long fine macrosetae on posterior inner side. Hypandrium ( Fig. 108 ) moderately robust. Transandrium ( Fig. 109 ) slightly more slender than in A. acuticuspis , medially with simple, broad, flat and pale-pigmented caudal process being distally widened, membranous and merged with basal membrane. Pregonite ( Fig. 108 ) low, similar to that of A. bivittata including its small posterior projecting lobe being separated from hypandrium by narrow incision, with 3 (1 long) posterior setae on tip of this projection and 3 (1 long) anterior setae inserted on inner side of anterior lobe of pregonite. Postgonite ( Fig. 108 ) slender, slightly curved but distally suddenly strongly bent knee-like, and with tapered apex; its proximal darker and more robust part with 1 setula in the middle of anterior margin and several grain-like sensilla on outer side. Basal membrane ( Figs 108, 109 ) with dense, pale, flat, spine-like excrescences. Aedeagal part of folding apparatus dorsally with a group of minute granulose tubercles, ventrally with fine, flat and pale transverse tubercles and anteriorly with usual fine striae. Connecting sclerite slender, submembranous, with very fine granulose structure ( Fig. 111 ). Phallapodeme with basal part deeply forked, fulcrum wide basally and tapered apically, and apex bicuspidate with projecting corners. Aedeagus with small phallophore higher than in relatives ( Fig. 111 ) and large distiphallus basally with internal elongate sclerites. Ventral sclerite connecting phallophore with ventrobasal sclerite of distiphallus distinctly angular. Saccus of distiphallus distally with rather numerous but small hyaline hemispherical tubercles only (as in A. bivittata ). Filum proximally dilated but this dilated part pale-pigmented, otherwise formed by 2 closely attached and partly fused ribbon-like sclerites ending in widened, curved and flat submembranous apex being distally split into several flat and bent projections ( Fig. 110 ), almost devoid of microspinulae. Ejacapodeme resembling that of A. acuticuspis with its digitiform projection with clubbed apex ( Fig. 111 ).

F e m a l e ( Fig. 101 ). Similar to male unless mentioned otherwise. Total body length 2.38–3.18 mm. No part of head coloured differently from that in male. f 1 with ctenidial spine somewhat shorter on the average, about as long as or slightly longer than maximum width of t 1. f 3 posteroventrally simply setulose. Wing measurements: length 2.58–3.22 mm, width 0.79–1.07 mm, Cs 3: Cs 4 = 1.07–1.56, rm\dm-cu: dm-cu = 1.86–2.36. Abdomen with preabdominal terga more transverse. T1 slightly shorter and narrower than T2. T2–T5 subequal in length, all sparsely and relatively shortly setose. Preabdominal sterna somewhat narrower and markedly lighter than in male, yellow to whitish yellow ( Fig. 100 ), finely setose. S1 short, transverse, not wider than S2, bare, with darker yellow posterior transverse stripe; S2 almost square; S3–S5 becoming larger and wider posteriorly but S3 and S4 about as long as wide, of similar shape to S2; S5 largest, widest, slightly wider than long but distinctly narrower than S6, the latter concolourous with preabdominal sterna.

Postabdomen ( Figs 114, 115 ) of medium length, basally wide, distally tapered. T6 large and brown, distinctly paler than T7+S7 dorsally, similar to that of A. bivittata but with setae sparse and restricted to posterior half. S6 narrower than T7+S7, pale-pigmented as S5, wider than that of A. acuticuspis and shorter than that of A. bivittata , with long setae at posterior and lateral margins. T7 and S7 completely fused to form annular tergosternum T7+S7 being dorsally and laterally blackish brown and shining (but with pale anterior marginal band—see Fig. 114 ), ventrally somewhat longer, with large pale brown to ochreous-yellow (medially paler) and microtomentose area (wider anteriorly, narrowed posteriorly) and a long, dark, transverse ledge-like anterior submarginal band ( Fig. 115 ). T7+S7 with longest setae ventrally and laterally at posterior margin. Membrane of 8th segment densely micropubescent, more in front of S8. T8 slightly elongate, anteriorly tapered and rounded, posteriorly wider with rounded corners, pale brown (lighter than T10) and with long micropubescence in anterior two-thirds. S8 shorter but not wider than T8, medially divided and forming usual 2 posterodorsally recurved and invaginated sclerites (see Fig. 120 ). Genital chamber ( Fig. 120 ) distally wider but without additional sclerotization; proximally with usual internal sclerotization formed by 1 pair of simple, flat but crooked sclerites and 1 narrow, flattened annular sclerite ( Figs 116, 117 ) having both ends (posterior strongly) curved ventrally and anterior part only slightly widened, thus more similar to that of A. bivittata although shorter. Ventral receptacle ( Figs 118, 119 ) slender and elongate, similar to those of close relatives, with middle part curved and distinctly ringed, long terminal part slender, plain and straighter but its apex twisted worm-like. Accessory gland hyaline, small, narrowly conical, on relatively slender, slightly distally widened duct. Spermathecae (1+1) pyriform ( Fig. 113 ), most resembling those of A. acuticuspis including darker constriction in proximal third and surface structure in distal two-thirds but more elongate and with spines in basal part more transversely arranged; also duct ( Figs 113, 120 ) and pale-pigmented cervix ( Fig. 113 ) more similar to that of A. acuticuspis . T10 small, darker and less transverse ( Fig. 114 ) than in the latter species, with posterior corners rounded and laterally darkened, with reduced micropubescence and 1 pair of very long medial setae ( Fig. 120 ). S10 paler and markedly larger than T10, rounded pentagonal ( Fig. 115 ) and micropubescent in posterior three-fourths. Cercus pale-pigmented, of moderate length and width, with a number of fine setae, dorsopreapical and apical longest ( Fig. 120 ).

Discussion: Arganthomyza duplex sp. n. forms together with A. acuticuspis sp. n and A. bivittata sp. n. a monophyletic group of exclusively Nearctic species. The monophyly of this group, named the A. duplex group here, is supported by at least two apomorphic characters (see also Fig. 173 ): the filum of the distiphallus basally widened (character 16) and the apex of the ventral receptacle vermicularly twisted (character 31). The latter character ( Fig. 118 ) resembles the condition (a homoplasy) known in Anthomyza species (cf. Roháček 2006) but it is believed that it evolved independently in this group of Arganthomyza from the plesiomorphic state of ventral receptacle with a simple apex (cf. Figs 132 , 159 ) as found in species of the A. socculata group which is postulated to be the sister group of the A. duplex group (see Fig. 173 ). Although more externally resembling A. acuticuspis and despite the marked colour dissimilarity, A. duplex sp. n. appears to be a sister species of A. bivittata sp. n. as demonstrated by two synapomorphies ( Fig. 173 ): the pale-pigmented female S2–S6 (character 09) and the gonostylus with the apex bent medially (character 11).

Among Arganthomyza species A . duplex sp. n. is well distinguished by its bicolourous pleurae (dark dorsally, pale ventrally), characteristic gonostylus (bent posteriorly) and sexually different colouration of the preabdominal sterna (brown in male, pale yellow in female), see also the key above. However, there is externally a very similar undescribed species of the Anthomyza macra group in North America which is difficult to distinguish from A. duplex sp. n. without examination of the male and female terminalia. This species usually differs from A. duplex sp. n. by the reduced subvibrissa, a short setula in front of the anterior orbital seta, and paler darkening of the apical tarsal segments but it is recommended to always verify its identification by the genitalic characters.

Biology: Three Nearctic species of Arganthomyza are often found together in eastern North America in at least pairs of species usually involving the more common A. duplex sp. n. and one of the other two ( A. bivittata sp. n., A. carbo sp. n.). Four sites are known to have yielded all three species (Sault Ste. Marie—Baseline Rd., Birchwood Pk., and Bristol Place Pk., Ontario and near Searchmont (Icewater Creek watershed), Ontario). Most eastern collections of A. duplex with habitat data suggest relatively mesic mixed forest (often dominated by aspen, Populus tremuloides Michx. , in Ontario) with thick and diverse ground vegetation ( Fig. 102 ). This understory usually includes a wide variety of plant species (some summarized under A. carbo sp. n. and many others listed in the material section here) and can be variously dominated by a few. The authors have suspected that ferns ( Fig. 103 ) may be at least an indicator of potential habitat but their role as host plants has not been evaluated. Besides, northwestern records suggest more open habitat such as grasses (Dunvegan and Cadomin, Alberta) and also pine forest (Carcross, YT), while some collections have been made in habitats not including ferns in the immediate vicinity (Westlock Co., Alberta). Adult flies have been collected from 9 April (Robson, BC) to 21–28 September (Tony Grove Jct., Utah).

Distribution: This is the most commonly collected and widely distributed species of Arganthomyza in North America and is transcontinental in both Canada and the northern United States —in Canada, from British Columbia and the Yukon Territory to Newfoundland and Nova Scotia (Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, Quebec, Saskatchewan, Yukon Territory) and the United States, from Washington and Idaho to New Mexico, New Hampshire and New York (Alaska, Colorado, Idaho, Michigan, Minnesota, Montana, New Hampshire, New Mexico, New York, Pennsylvania, Utah, Vermont, West Virginia, Wyoming). At least some of the most southwesterly specimens have been taken at altitudes above 9000 ft (Colorado, New Mexico, Utah).

Figures

FIGURE 173. One of two most parsimonious trees (L = 42 steps, CI = 0.80, RI = 0.81) chosen to represent the phylogeny of Arganthomyza species. Ambiguous characters (08, 13, 14, 18, 21, 29) are optimized using the fast (ACCTRAN) method. Full circles = non-homoplasious character states, empty circles = homoplasious character states. Numbers above branches agree with character numbering, those below branches indicate apomorphic (1, 2, 3) or plesiomorphic (0) states of characters. E PA = East Palaearctic, HO = Holarctic, NA = Nearctic, OR = Oriental, PA = Palaearctic.

FIGURES 1–6. General body appearance of Arganthomyza species, lateral (1–5) and dorsal (6, head and thorax only). 1—A. acuticuspis sp. n. (male holotype). 2—A. carbo sp. n. (male holotype). 3—A. duplex sp. n. (male holotype). 4—A. disjuncta sp. n. (female holotype). 5, 6—A. bivittata sp. n. (male holotype).

FIGURES 100–105. Habitus and habitats of Arganthomyza species. 100–101. A. duplex sp. n. alive (Dubreuilville, Ontario, Canada), mating pair laterally (100), female dorsolaterally (101). 102, 103—habitat of A. duplex and A. carbo, fern-dominated undergowth of mixed forest at Dubreuilville with K. N. Barber collecting (102), with detail (103). 104, 105—habitat of A. disjuncta sp. n., montane meadow; detail with Bromus inermis at Cadomin and general view (105) near Little Highwood Pass (both Alberta, Canada). Photo by J. Roháček (100–103) and K. N. Barber (104, 105).

FIGURES 106–112. Arganthomyza duplex sp. n. (male paratype, Canada: Ontario). 106—external genitalia, caudal. 107—ditto, lateral. 108—hypandrial complex, lateral. 109—transandrium, caudal. 110—apex of filum of distiphallus, anteroventral (widest extension). 111—aedeagal complex, lateral. 112—gonostylus, lateroventrocaudal (widest extension). Scales: 0.1 mm.

FIGURES 113–120. Arganthomyza duplex sp. n. (female paratype, Canada: Ontario). 113—spermathecae. 114—postabdomen, dorsal. 115—ditto, ventral. 116—internal sclerites, ventral. 117—ditto, lateral. 118, 119—ventral receptacle, whole lateral (118), apex ventral (119). 120—apex of postabdomen and female genital chamber, lateral. Scales: Fig. 113 = 0.05 mm, Figs 114, 115 = 0.2 mm, others = 0.1 mm.

FIGURES 166–169. Wings of Arganthomyza species. 166—A. carbo sp. n. (male paratype, Canada: Ontario). 167—A. acuticuspis sp. n. (male paratype, USA: New Mexico). 168—A. bivittata sp. n. (male paratype, Canada: Ontario). 169—A. duplex sp. n. (male paratype, Canada: Ontario). Scale: 0.5 mm.

FIGURES 129–136. Arganthomyza disjuncta sp. n. (female paratype, Canada: Alberta). 129—spermathecae. 130—postabdomen, dorsal. 131—ditto, ventral. 132—ventral receptacle, lateral. 133—internal sclerites, ventral. 134—ditto, lateral. 135—S10, ventral. 136—apex of postabdomen and female genital chamber, lateral. Scales: Figs 130, 131 = 0.2 mm, Figs. 135, 136 = 0.1 mm, other = 0.05 mm.

FIGURES 152–159. Arganthomyza socculata (Zetterstedt) (female, USA: Alaska). 152—spermatheca. 153—postabdomen, dorsal. 154—apex of postabdomen and internal sclerites, lateral. 155—internal sclerites, ventral. 156—end of female genital chamber, lateral. 157—spermatheca. 158—postabdomen, ventral. 159—ventral receptacle, lateral. Scales: Figs 153, 158 = 0.2 mm, Figs 154–156 = 0.1 mm, others = 0.05 mm.