Cerodontha (Dizygomyza) magnicornis (Loew)

Eiseman, Charles S. & Lonsdale, Owen, 2019, New State and Host Records for Agromyzidae (Diptera) in the United States, with the Description of Ten New Species, Zootaxa 4661 (1), pp. 1-39 : 10

Cerodontha (Dizygomyza) magnicornis (Loew)

( Fig. 12 )

Material examined. IOWA: Winneshiek Co., Fern Hollow , 31.v.2017, em. 10.vi.2017, J. van der Linden, ex Carex (section Laxiflorae), #CSE3882, CNC940120 (1³) ; OKLAHOMA: Payne Co., Mehan , 36.014339° N, - 96.996744° W, 20.iv.2017, em. 1.v.2017, M.W. Palmer, ex Carex festucacea , #CSE3608, CNC939888 (1♀) .

Hosts. * Cyperaceae : Carex sp. (section Laxiflorae), C. festucacea Schkuhr ex Willd. Foote (2004) swept an adult from C. lacustris Willd.

Leaf mine. Elongate, whitish to greenish, with the dark frass deposited in a single large lump.

Puparium. Brown; formed within the mine, toward the leaf base from the frass lump.

Distribution. USA: CO, DC ( Frick 1959), * IA, IL, IN, MI, NH, OH ( Foote 2004), * OK, PA, TN. Frick’s (1959) record from Canada: BC requires confirmation. Spencer (1969) treated this species as a synonym of C. (D.) morosa (Meigen) , and it is unclear to which species his records from ON and QC refer.

Comments. This species has not been reared previously. The leaf mine appears to be indistinguishable from that of the closely related C. (D.) morosa , which also feeds on Carex spp. Adults of these two species are readily differentiated, with C. magnicornis ( Fig. 12 ) having shoulders that are distinctly light yellow to whitish (not gray or with slight yellowish tint) and femora that are all distinctly light yellow apically (similar in some C. morosa , but apices of mid and hind femora usually much darker). The phallus of C. magnicornis ( Spencer & Steyskal 1986: Fig. 595) is also much shorter and more shallowly curved.

Figures

FIGURES 6–13. Figs. 6–7: Aulagromyza cornigera (Griffiths); 6: adult male; 7: puparium. Figs. 8–9: Calycomyza enceliae Spencer; 8: adult female; 9: puparium. Figs. 10–11: Calycomyza smallanthi spec. nov.; 10: adult male; 11: puparia. Fig. 12: Cerodontha (Dizygomyza) magnicornis (Loew), adult female. Fig. 13: Cerodontha (Icteromyza) longipennis (Loew), puparium.