Agromyza aristata Malloch, 1915

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

Agromyza aristata Malloch

Figs 37 , 161-166

Agromyza aristata Malloch, 1915b: 13. Frick 1957: 199; Spencer 1969: 38; Spencer and Steyskal 1986b: 59; Eiseman and Lonsdale 2018: 8; Eiseman et al. 2021: 5.

Phytagromyza aristata . Frick 1952a: 416.

Agromyza ulmi Frost, 1924: 54. Frick 1952a: 375. Frick 1959 [synonymy].

Agromyza marmorensis Spencer, 1969: 48. Syn. nov.

Description

(Fig. 37 ). Wing length 2.0-2.1 mm (♂), 2.3-2.4 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 0.6-0.9. Eye height divided by gena height: 1.9-2.7. First flagellomere subcircular, without apical tuft of pale hairs. Fronto-orbital plate (more so anteriorly) and parafacial strongly projecting and distinctly continuing under eye as cheek. Ocellar triangle relatively small with corners rounded. Palpus relatively ovate.

Chaetotaxy: Two ori; two ors. Ocellar seta thinner than postocellar, and sometimes shorter, but never reaching 1/2 length. Three postsutural dorsocentrals, decreasing in length anteriorly; possibly two more anteriorly that are not much longer than surrounding setulae. Acrostichal seta not much longer than surrounding setulae. Four scattered rows of acrostichal setulae. Mid tibia without posteromedial setae.

Colouration: Head predominantly light yellow; first flagellomere yellow; back of head brown above foramen and with grey pruinosity dorsally; ocellar triangle dark brown; posterolateral corner and posterior margin of frons brownish, with spot extending laterally to just behind level of anterior ors; clypeus light brown; face white. Thorax dark brown, covered with grey pruinosity, halter white. Calypter margin and hairs white to yellow. Legs yellow with mid and hind coxae brown, at least in part. Abdomen dark brown; epandrium yellow or with orange to brown tint with dark brown dorsal spot; if epandrium yellow, sternite 8 sometimes also yellow with medial spot.

Genitalia: (Figs 161-166 ) Surstylus fused with epandrium with suture obliterated, shape triangular (nearly equilateral), directed inwards, with several setae along posterior margin. Cercus relatively broad and flat with inner surface covered with pointed tubercle-like setae. Hypandrium setulose, slightly sinuate, and inner lobe with medial desclerotisation. Postgonite short. Phallophorus fused to single sclerite of basiphallus, which originates on left side and is twisted dextrally. Hypophallus membranous with faint left lateral sclerotisation. Mesophallus long, narrow, dark, and flat, lying along ventral margin of membrane; distiphallus short, flat and wrapped ventrally (nearly cylindrical), shortest dorsally. Ejaculatory apodeme minute and finger-like.

Hosts.

Cannabaceae - Celtis laevigata , C. occidentalis , C. pallida (leaf mine only); Ulmaceae - Ulmus alata (leaf mine only), U. americana , U. rubra ( Eiseman et al. 2021).

Distribution.

Canada: AB, NB*, ON, QC*. USA: IL, IN, IA, KS*, MI*, NY, OH, PA, VA, VT; known from leaf mines in AL, AR, CO, CT, FL, GA, MA, MD, MN, ND, NJ, TN, TX, WI.

Type material.

Holotype [aristata]: USA. IL: Havana, Gleason’s Sand Dune, 30.iv.1914, C.A. Hart and J.R. Malloch (HT ♀, INHS). [Not examined]

Paratypes examined

[aristata]: USA. IL: St. Joseph, Salt Fork, 3.v.1914, Type No. 2726, CNC352790 (1♀, CNC), PA: Arendtsville, 27.iv.1923, S.W. Frost (3♂, USNM).

Syntype [ Agromyza ulmi ]: USA. PA: Arendtsville, 22.iv.1923, S.W. Frost (1♂, USNM; type No. 50033).

Holotype [ Agromyza marmorensis ]: Canada. ON: Marmora, 7.v.1952, J.R. Vockeroth (HT ♂, CNC).

Additional material examined.

Canada. AB: Onefour , on wild cherry blossom, 2.vi.1956, O. Peck, CNC353069, CNC353072, CNC352809 (2♂, 1♀, CNC), NB: Curventon, 19.v.1959, W.W. Moss, C-2, CNC352810 (1♀, CNC), ON: Almonte, 18.v.1951, J.F. McAlpine, CNC352788, CNC352803-352806 (1♂, 4♀, CNC), Marmora, 16.v.1952, J.C. Mitchell, CNC352786 (1♂, CNC), 30.iv.1952, J.F. McAlpine, CNC352802 (1♀, CNC), Marmora, 28.iv.1952, J.F. McAlpine, CNC352787 (1♂, CNC), Metcalfe, 14.v.1994, B.E. Cooper, CNC353066 (1♂, CNC), 17.v.1994, CNC353067 (1♂, CNC), 7.v.1994, CNC353068 (1♂, CNC), Midland, swampy wood, 26.v.1959, J.G. Chillcott, CNC353071 (1♂, CNC), Nippising, 27.ii.1959, #83, S58-1-1381-01, CNC352779 (1♂, CNC), Ottawa nr. Uplands Airport, 22.v.1990, J.M. Cumming, CNC353064 (1♂, CNC), Ottawa, damp second-growth Acer - Betula wood, 1.vi.1995, J.R. Vockeroth, CNC353063 (1♂, CNC), 28.v.1995, CNC353070 (1♂, CNC), at sap on Acer stump, 10.v.1991, J.R. Vockeroth, CNC353062 (1♂, CNC), bleeding elm, 22.v.1952, J.F. McAlpine, CNC352791 (1♀, CNC), 28.v.1951, J.F. McAlpine, CNC352794 (1♀, CNC), 5.v.1952, B. Hartley, CNC352783 (1♂, CNC), J.G. Chillcott, CNC352783-352795, CNC352780, CNC352792 (2♂, 3♀, CNC), 8.v.1952, J. Chillcott, CNC352782, CNC352785, CNC352796-352800 (2♂, 5♀, CNC), Pt. Pelee, 3.vi.1929, G.S. Walley, CNC352801 (1♀, CNC), QC: Hemmingford, 10.v.1931, J.B. Maltais, CNC352807 (1♀, CNC), Old Chelsea, 8.v.1938, G.E. Shewell, CNC352808 (1♀, CNC) . USA. IL: White Heath, 30.iv.1916 (1♀, USNM), Champaign, 28.iv.1953, J.F. McAlpine, CNC352789 (1♂, CNC), IN: Lafayette, J.M. Aldrich, 4.v.1916 (1♂, USNM), 11.v.1916 (1♀, USNM), KS: Manhattan, C.W. Sabrosky, 27.iv.1934 (1♀, USNM), 17.vi.1934 (1♀, USNM), Lawrence, Nat. Hist. Res., 27.iii.1954, J.G. Chillcott, CNC352781 (1♂, CNC), 28.v.1956, J.G. Chillcott, CNC352811-352818 (8♀, CNC), MI: Detroit, 24.v.1935, G. Steyskal (1♂, USNM), E Lansing, C. Sabrosky, 2.vi.1934 (1♀, USNM), 29.iv.1942 (1♀, USNM), NC: Scotland Co., Laurinburg, St. Andrews University , 18.iv.2017, T.S. Feldman, Celtis laevigata , em. ~ 17.iv.2018, #CSE4418, CNC1144090 (1♀, CNC), OK: Payne Co. , Mehan , 36.014339°N, 96.996744°W, 5.iv.2016, em. by 11.iv.2017, M.W. Palmer, ex Ulmus rubra , #CSE3448, CNC939912 (1♂, CNC), VA: Chain Bridge , 23.iv.1922, J.R. Malloch (1♀, USNM), Fairfax Co. , Great Falls Park , quarry, 38°59.1'N, 77°14.8'W, Malaise trap, D.R. Smith, 18-23.iv.2007 (2♀, USNM), 13-24.v.2007 (1♀, USNM), VT: USA. Vermont: Chittenden Co. , South Burlington , Winooski Gorge , 16.v.2015, C.S. Eiseman, Ulmus rubra , em. 24.iii-6.iv.2016, #CSE2264, CNC654497-654499 (3♀, CNC) .

Comments.

The dissected paratype of Agromyza aristata discussed by Spencer (1969) has been examined and the genitalia are identical to those of the male illustrated here, not as illustrated in Spencer (1969). The unusual illustration in Spencer (1969) appears to belong instead to a non-type male in the USNM from Illinois that has had the phallus broken off near the base of the mesophallus. This mistake in interpreting the male genitalia led Spencer to describe A. marmorensis in the same revision, stating that while "Not satisfactorily distinguishable from A. aristata " based on external characters, the differences in the genitalia were significant enough to separate them. Since it is now clear that the genitalia of the two species are also identical, A. marmorensis is here included as a junior synonym of the senior A. aristata .

The new records for NB, QC, MI and KS represent new adult records, but these were previously suspected from leaf mines ( Eiseman et al. 2021).

Figures

Figures 37 - 44. 37 Agromyza aristata Malloch, female lateral 38 Agromyza bispinata Spencer, female lateral with detail of stridulatory file 39, 40 Agromyza kincaidi Malloch, male head (arrow indicates discrete apical tuft of hairs) 39 lateral 40 same, anterior 41, 42 Agromyza bispinata, male head 41 lateral 42 same, anterior 43 Agromyza sp., female (S. A. Marshall - Ontario, Hornings Mills) 44 Euhexomyza schineri (Giraud) (T. Murray - Massachusetts, Groton).

Figures 161 - 166. Agromyza aristata Malloch, male genitalia 161 external genitalia, left lateral 162 external genitalia, ventral 163 ejaculatory apodeme 164 hypandrium and postgonite, ventral 165 hypandrial complex, left lateral 166 phallus, ventral.