Amauromyza flavifrons (Meigen)

Lonsdale, Owen, 2021, Manual of North American Agromyzidae (Diptera, Schizophora), with revision of the fauna of the " Delmarva " states, ZooKeys 1051, pp. 1-481 : 1

Amauromyza flavifrons (Meigen)

Figs 84 , 85 , 418-424 , 429

Agromyza flavifrons Meigen, 1830: 184.

Agromyza exigua Meigen, 1830: 184. Hendel 1931 [synonymy]. Spencer and Martinez 1987 [synonymy].

Agromyza xanthocephala Brischke, 1881: 242 [nec. Zetterstedt]. Hendel 1931 [synonymy].

Dizygomyza (Trilobomyza) flavifrons . Hendel 1931: 71.

Trilobomyza flavifrons . Spencer 1969: 160.

Amauromyza (Trilobomyza) flavifrons . Spencer 1972: 46, 1987: 877.

Amauromyza (Cephalomyza) flavifrons . Spencer and Steyskal 1986b: 275; Scheffer et al. 2007: 770; Boucher 2012b: 744; Černý et al. 2020: 201.

Amauromyza flavifrons . Scheffer and Lonsdale 2018: 86; Eiseman and Lonsdale 2018: 25; Eiseman et al. 2021: 20.

Description

(Figs 84 , 85 , 429 ). Wing length 1.8-2.3 mm (♂), 2.0-2.4 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 2.3-3.3. Eye height divided by gena height: 3.9-4.7. Gena shallow, highest posteriorly and strongly angled upwards anteriorly. Epistoma shallow and broadly rounded. Fronto-orbital plate and parafacial soft, fronto-orbital plate somewhat visible laterally. Lunule height ~ 0.6-0.8 × width. First flagellomere subcircular, with minute tuft of slightly longer hairs apically. Distance between cross-veins approximately as long as dm-m or shorter.

Chaetotaxy: Two or three ori; two or three ors (rarely one). Orbital setulae short, dark and erect, but sometimes strengthened and appearing as shorter additional ori. Setulae on tubercle strong, erect. Postocellar and ocellar setae as long as ors, with ocellar slightly shorter. Four dorsocentrals, one presutural; decreasing in length anteriorly; sometimes with additional strengthened setula near suture. Acrostichal setulae in four to five scattered rows.

Colouration: Setae dark brown. Body colour faintly to strongly infused with orange tint. Head mostly yellow; first flagellomere light brown to brown excluding base, but sometimes more broadly yellowish; pedicel brownish (sometimes yellow apically); back of head dark brown; posterolateral corner of frons dark brown to base of vertical setae; palpus, face, clypeus, and lower margin of gena brown; gena sometimes brownish. Thorax dark brown with light dusting of pruinosity. Halter yellow. Calypter margin and hairs brown. Legs dark brown with apex of fore femur yellow. Abdomen dark brown.

Genitalia: (Figs 418-424 ) Epandrium fused with surstylus, interface evident by partial suture; surstylus setose, short, broadly lobate; surstylus and posterodistal margin of epandrium curved inwards. Subepandrial sclerite consisting of one pair of well-sclerotised lateral plates (one seta each apically) joined by broad membranous space medially; with weakly sclerotised triangular lobe underneath cerci. Epiphallus weakly sclerotised, but divided into one pair of ill-defined plates with four strong ridges on anterior plate that are weakly attached to strong saddle-shaped basal plate meeting phallophorus. Hypandrium small, broadly rounded and stout. Postgonite bare, curved medially, with weak inner-medial lobe, apically subcircular with distal 1/2 weakly sclerotised. Ejaculatory duct broad, lightly pigmented, becoming darker and slightly wider apically. Basiphallus with weak subquadrate dorsobasal plate distally branching (from left side) into two darker bands, the right band wider with dorsum paler; apically narrowed and paler, medially fusing with broad, black ventral extension of distiphallus (possibly homologous to paraphalli). Mesophallus not discernible, likely fused into base of distiphallus. Distiphallus as long as distance from its base to apex of phallophorus; black, split along most of length into two stout processes that slightly widen apically; membrane surrounding distiphallus with minute clear spinulae around apex with medial line smoother. Ejaculatory apodeme paler to apex, broad blade continuous with stem, gradually tapering to base; sperm pump sclerotised, broadly bowl-shaped or somewhat pointed ventromedially.

Hosts.

Amaranthaceae - Beta, Spinacia . Asteraceae - Bidens *; two ON females reared from "Wild Aster ". Caryophyllaceae - Agrostemma , Atocion , Atriplex , Cerastium , Dianthus , Gypsophila , Honckenya , Lychnis , Melandrium , Moehringia , Myosoton , Saponaria , Silene , Stellaria , Vaccaria . Chenopodiaceae - Chenopodium , Spinacia ( Benavent-Corai et al. 2005; Eiseman et al. 2021; Ellis 2021).

Distribution.

Canada: BC, ON, QC. USA: DE, IL, MA, MD*, MI, MN, NC*, NY, OH, OR, PA, VA*, VT, WA; leaf mines only in CT, IA, ID, KY, WI ( Eiseman and Lonsdale 2018). Tunisia, Western Europe to the Kyrghyz Republic and North Korea ( Spencer 1976; Černý et al. 2020).

Type material.

Holotype: Germany (1♀, MNHN). [Not examined]

Material examined.

Canada. BC: Vancouver, Point Grey, 17.ix.1972, J.R. Vockeroth (3♂, CNC), ON: Ottawa, 695 Malibu Tr., 45°22'16.29"N, 75°42'57"W, 20.vi.2017, O. Lonsdale, ex Silene vulgaris , em. 6.vii.2017, CNC799453, CNC799454 (2♀, CNC), Ottawa, 23.viii.1971, ex wild Aster , H.J. Teskey (2♀, CNC), Ottawa, winter 1965-66, bred from leaf mine in Dianthus , M. Hildebrand, reared in lab (1♂, CNC), Ottawa, 23.v.1975, H.C.W. Walther (1♀ 4 puparia, CNC), Ottawa, 21.viii.1974, J.R. Vockeroth (1♂, CNC), Ottawa, damp second-growth Acer - Betula wood, J.R. Vockeroth, 21.v.1991 (1♂, CNC), 25.v.1991 (2♂, CNC), 26.vi.1991 (2♀, CNC), 6.vii.1991 (1♀, CNC), 9.vii.1991 (1♀, CNC), 11.vii.1991 (1♀, CNC), 17.vii.1993 (5♂, CNC), 8.viii.1993 (1♀, CNC), 13.viii.1993 (1♂, CNC), 28.viii.1993 (1♂, CNC), 12.vii.1994 (4♂, CNC), 30.v.1995 (1♂, CNC), 29.viii.1997 (1♂, CNC), 1.ix.1997 (1♂, CNC), 6.xi.1997 (1♂, CNC), 14.viii.1998 (1♂, CNC), 5.vii.2000 (1♂, CNC), 11.vii.2000 (1♂, CNC), 12.vii.2000 (1♂, CNC), 12.viii.2000 (1♂, CNC), 15.viii.2000 (1♂, CNC), 21.viii.2000 (1♂, CNC), 27.viii.2000 (1♂, CNC), 29.viii.2000 (1♂, CNC), 2.x.2000 (1♀, CNC), 16.vii.2002 (1♂, CNC), 22.viii.2002 (1♂, CNC), 16.ix.2002 (1♂, CNC), 14.vii.2003 (2♂, CNC), 15.vii.2003 (2♂, CNC), 3.viii.2003 (1♂, CNC), 21.viii.2003 (1♂, CNC), 24.viii.2002 (2♂, CNC), Thornhill, J.R. Vockeroth, 30.v.1964 (29♂ 33♀, CNC), Metcalf, 28.vii.1993, B.E. Cooper (2♂, CNC), St. Lawrence Is. N.P., Grenadier I. Centre, 28.vii.1975, E. Sigler (2♂, CNC), QC: Gatineau Pk., Old Chelsea, H.J. Teskey, 28, vii.1971 (1♂ 1♀ [with puparium], CNC), viii.1971 (1♀, CNC), Hull, Diptera on Bidens , 25.viii.1960, C.D. Miller (1♀ [with puparium and host leaf], CNC). England. Torcross, Devon, 14.vii.1942, G.E. Shewell (1♀, CNC). Europe. No data, "Dizygom. flavifrons Mg. ♂ det. Hendel" (1♂, USNM), "Dizygom. flavifrons Mg. det. Hendel" (1♂, USNM). Germany. Mine an: Cerastium holosteoides , Hering Z: Crossen a.O., 1964, Mühlhausen Thüringen, H. Buhr, 2298 (2♂ [same pin], CNC), Mine an: Coronaria floscuculi [= Lychnis flos-cuculi L.], Crossen a.O., Hering: Z. (1♀, CNC). Hungary. Budapest, Janoshed, em. 21.vi.1964, mine Melandrium sp. 28.v.1964, K.A. Spencer (1♀ [with puparium], CNC). USA. MD: Colesville, W.W. Wirth, 11.vii.1974 (1♀, USNM), 24.vii.1974 (1♂ 2♀, USNM), 14.vi.1975 (1♀, USNM), 4.vii.1976 (2♀, USNM), 28.vii.1976 (2♀, USNM), 14.vi.1977 (1♀, USNM), 18.vi.1977 (1♀, USNM), 28.v.1977 (1♂, USNM), 26.vi.1977 (2♂, USNM), Montgomery Co., Colesville, 3.viii.1979, Malaise trap, W.W. Wirth (1♀, USNM), OH: Portage Co., 3mi E Kent, 10.vi.1969, Biol. Note No. 6901, S. Whitney (1♀, USNM), Hocking Co., South Bloomingville, Deep Woods Farm, 24.x.2013, em. 26- 28.iii.2014, C.S. Eiseman, ex Silene rotundifolia , #CSE1028, CNC384742-384747 (6♀, CNC), OR: Lane Co., Blue River, 24.vii.2016, M.W. Palmer, Silene coronaria em. 18-30.vii.2016, #CSE3037, CNC638887-638890 (3♂, 1♀, CNC), NC: Jackson Co., Dulaney Bog, 7mi S Cashiers, 19.vi.1986, Malaise trap, W.W. Wirth (1♀, USNM), VA: Giles Co., Mountain Lake, 7.ix.1976, G.C. Steyskal (1♂, USNM), Fairfax Co., Turkey Run Park, 0.3 km W mouth Turkey Run, 38°58'N, 77°09.6'W, Malaise trap, 12-26.vii.2007, D.R.Smith (1♀, USNM).

Comments.

Amauromyza flavifrons , a distinct black and yellow to orange-tinted species that often has numerous fronto-orbitals, was first collected in North America by J.R. Vockeroth in Thornhill, Ontario in 1964. Spencer (1969) suggested that it may have been introduced from Europe on cultivated Dianthus . Collection records support this concept, showing the geographic spread of this species in subsequent years: from Ohio in 1969, Vancouver in 1972, Washington in 1973, Maryland in 1974, Wisconsin in 1975 ( Spencer and Steyskal 1986b), Edmonton in 1975 (G.C. Griffiths, pers. comm.), Virginia in 1976, Delaware in 1979 ( Spencer and Steyskal 1986b), Vermont in 1980 and North Carolina in 1986. The Edmonton specimens were reared from Dianthus barbatus , emerging on 24-26 July; other mines were only seen within the city on garden plants and weeds, supporting the idea that they were first introduced on commercial plants (G.C. Griffiths, pers. comm.).

Amauromyza flavifrons is known to regularly occur on beet and spinach, but normally low population densities keep it from becoming a serious pest ( Dempewolf 2004). The anthomyiid Pegomya Macquart also occurs on beet, and mines of one may be confused for the other, although those of Pegomyia are much larger, darker, and more damaging to the leaves (C. Eiseman, pers. comm.). Similar damage on Dianthus (carnations) causes proportionally more damage, significantly decreasing market value.

Figures

Figures 84 - 91. Amauromyza flavifrons (Meigen), head 84 anterior 85 lateral 86, 87 Amauromyza karli (Hendel), head 86 dorsal 87 lateral 88 Aulagromyza nitida (Malloch), male, lateral 89 Aulagromyza tridentata (Loew), male, lateral 90, 91 Calycomyza enceliae Spencer, male, on bush sunflower (R. Hemberger - California, Irvine).

Figures 418 - 424. Amauromyza flavifrons (Meigen), male genitalia 418 ejaculatory apodeme 419 external genitalia, anterior (subepandrial sclerite shaded) 420 external genitalia, ventral 421 hypandrium and postgonite, ventral 422 postgonite, lateral 423 phallus, ventral 424 phallus, left lateral.

Figures 425 - 430. Amauromyza karli (Hendel), male genitalia 425 hypandrium and postgonite, ventral 426 hypandrial complex, left lateral 427 phallus, ventral 428 ejaculatory apodeme 429, 430 wings 429 A. flavifrons (Meigen) 430 A. karli.