Cerodontha (Xenophytomyza) illinoensis (Malloch)

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

Cerodontha (Xenophytomyza) illinoensis (Malloch)

Figs 104 , 567-573

Agromyza illinoensis Malloch, 1934: 483. Frick 1952a: 374.

Cerodontha (Xenophytomyza) illinoensis . Frick 1952c: 151; Spencer and Steyskal 1986b: 92; Boucher 2003: 6.

Phytobia (Xenophytomyza) illinoensis . Frick 1959: 397.

Cerodontha (Poemyza) simcoensis Spencer, 1969: 135. Spencer and Steyskal 1986b [synonymy].

Description

(Fig. 104 ). Wing length 2.0-2.2 mm (♂), 2.2-2.4 mm (♀). Length of ultimate section of vein M4 divided by penultimate section: 1.5-2.0. Eye height divided by gena height: 9.0-10.0. First flagellomere slightly longer than high, anterodorsal margin forming strong angle. Arista pubescent. Frons slightly narrowing anteriorly, very soft, not smoothly meeting lunule. Fronto-orbital plate 1/4 width of frons, slightly visible laterally; ocellar triangle large, approximately equilateral with sides rounded; parafacial very narrow, continuing as narrow “cheek”; gena angled upwards. Gena and frons with minute scattered pits that are much denser and darker on frons; pits not present on fronto-orbital plate, reduced on ocellar triangle, becoming absent medially on tubercle.

Chaetotaxy: Two to three ori; two ors; decreasing in length anteriorly with anterior seta as small as 2/3 length of posterior ors. Orbital setulae relatively long, scattered, in one or two rows on either side of fronto-orbitals. Ocellar and postocellar setae subequal to ors; ocellar setae slightly displaced laterally to level of outer ocelli. Four dorsocentral setae strongly decreasing in length anteriorly, with fourth seta often indistinguishable from surrounding setulae (not visible in material examined), and third at most 1/3 length of first seta. Acrostichal seta absent. Approximately eight scattered rows of acrostichal setulae reaching level of posterior dorsocentral. Lateral scutellar seta absent.

Colouration: Setae dark brown. Body dark brown; fronto-orbital plate and region around margin of ocellar triangle paler; antenna paler with first flagellomere darkest of segments; apex of fore femur yellow for length less than width of femur. Calypter margin and hairs brown. Halter yellow. Wing veins brown, only yellow at very base.

Genitalia: (Figs 567-573 ) Epandrium without process above anus; fused to surstylus with suture absent. Surstylus broad, short, slightly produced past margin of epandrium, directed inwards, margin setose. Subepandrial sclerite with ventral lobe narrow, dark, apically tapering and with slight outer-distal point. Basiphallus apically split. Hypophallus flat, long, faded and narrowed apically. Paraphallus absent. Mesophallus fused to distiphallus, forming long, clear, narrow tubule that is longer than remainder of phallus; slightly swollen basally and appearing partially split apically. Ejaculatory apodeme with small, rounded, mostly clear blade, and dark, narrow stem with minute clear subbasal process; sperm pump clear.

Host.

Unknown, likely Poaceae (Boucher 2003).

Distribution.

Canada: ON. USA: IL, MS*, TN, VA, VT*, WV*.

Type material.

Syntypes [illinoensis]: USA. IL: White Heath, 22.v.1915 (3♀), 8.v.1915 (1♀ 1♂), 9.v.1915 (2♂), 16.v.1915 (2♀), 30.v.1915 (2♀). [Types in INHS, USNM]. [Not examined]

Holotype [ Cerodontha simcoensis ]: Canada. ON: Simcoe, 9.vi.1939, G.E. Shewell, CNC481017 (1♂, CNC).

Paratypes [ Cerodontha simcoensis ]: Canada. ON: Simcoe, 9.vi.1939, G.E. Shewell, CNC481018-481020 (2♂ 1♀, CNC).

Additional material examined.

Canada. ON: Ottawa , Stony Swamp, Beaver Trail, 45°18'0"N, 75°49'16"W, 13.vi.2015, O. Lonsdale, CNC441042, CNC441054, CNC441059, CNC441073, CNC441084 (5♂, CNC), Ottawa, 17.vi.1954, C.D. Miller, CNC481023 (1♀, CNC) . USA. MS: Winston Co., Noxubee NWR, Loakfoma Crk., at Dummy Line Rd. , 33°15'9"N, 88°50'53.01"W, 17-21.v.2013, J.M. Cumming, Malaise trap, CNC481024 (1♀, CNC), TN: East Ridge , 4.v.1952, O. Peck, CNC481021 (1♂, CNC), 6.v.1952, CNC481022 (1♀, CNC), VA: Fairfax Co. , Dead Run, 19.vi.1915, R.C. Shannon (1♂, USNM), VT: Rutland Co. , nr. Benson, hwy 22A, 1mi N hwy 144, 22.vi.1997, sweeping, C.R. Bartlett (1♀, UDCC), WV: Grafton, 25.vi.1970, G. Steyskal (1♂, USNM), Summers Co., Pipestem, 18.vi.1970, G. Steyskal (1♂, USNM) .

Figures

Figures 99 - 106. 99 Cerodontha (Butomomyza) angulata (Loew), head, anterior 100 Cerodontha (Phytagromyza) frankensis Spencer, head, anterior 101 Cerodontha (Poemyza) muscina (Meigen), head, anterior 102 Cerodontha (Poemyza) incisa (Meigen), head, anterior 103 Cerodontha (Icteromyza) longipennis (Loew), head, anterior 104 Cerodontha (Xenophytomyza) illinoensis (Malloch), head, anterior 105 Cerodontha (Dizygomuza) morosa (Meigen), head, anterior 106 Cerodontha (Cerodontha) dorsalis (Loew), (K. Matz - Utah, Salt Lake City).

Figures 567 - 573. Cerodontha (Xenophytomyza) illinoensis (Malloch), male genitalia 567 external genitalia, anterior 568 external genitalia, left lateral 569 external genitalia, ventral 570 hypandrium and postgonite, ventral 571 ejaculatory apodeme 572 phallus, ventral 573 phallus, left lateral.