Cerodontha (Icteromyza) longipennis (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 : 10-11

Cerodontha (Icteromyza) longipennis (Loew)

( Figs. 13 , 42, 43 )

Material examined. MASSACHUSETTS: Berkshire Co., Lenox, Parsons Marsh , 20.vi.2017, em. by 7.vii.2017, C.S. Eiseman, ex Carex pseudocyperus , #CSE3901, CNC939712 (1³).

Hosts. * Cyperaceae : Carex pseudocyperus L.; Juncaceae : Juncus xiphioides E. Mey. ( Frick 1959) .

Leaf mine. ( Figs. 42, 43 ) On Carex pseudocyperus , elongate and whitish, on the upper leaf surface. The mine from which the adult emerged contained a single larva and was formed along the leaf margin; an associated mine contained two larvae and was formed in the center of a leaf. No frass was evident to the naked eye, with minute, fine strips visible in transmitted light under magnification (and with a small cluster of thicker particles near the puparium). Frick (1959) reared this species from both leaf and stem mines on Juncus xiphioides but gave no further details.

Puparium. ( Fig. 13 ) Brown, elongate, with deep intersegmental grooves; formed within the mine.

Distribution. Known from almost all American states and Canadian provinces ( Boucher 2012).

Comments. This is the first record of a species of Cerodontha (Icteromyza) from Carex . Besides Juncus (Juncaceae) , the only other confirmed host for the subgenus is Eriophorum L.; there is also an unconfirmed record from Fimbristylis Vahl (both Cyperaceae ) ( Boucher 2012). Frohne (1938, 1939) reported C. longipennis as a stem miner on Schoenoplectus acutus (Muhl. ex Bigelow) Á. L̂ve & D. L̂ve var. occidentalis (S. Watson) S.G. Sm. and S. americanus (Pers.) Volkart ex Schinz & R. Keller (Cyperaceae) in Michigan, but these records require confirmation. He stated that the larvae mine downward, forming “varicose elongated blotch mines” that often end below the water level. When mature, they are green and about 7 mm long; puparia are about 5 mm by 2 mm. Since our C. longipennis puparia are only 2.5 mm long, we are skeptical that his observations refer to the same insect. In our experience puparium length of agromyzids is roughly equal to wing length, and Boucher (2012) reported wing lengths of 1.9–3.1 mm for C. longipennis based on examination of 449 specimens.

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.

FIGURES 34–45. leaf mines: 34: Agromyza princei spec. nov., on Rubus occidentalis; 35: Ophiomyia antennariae spec. nov., on Antennaria plantaginifolia; 36: same; 37: Aulagromyza cornigera (Griffiths), on Lonicera x bella; 38: Calycomyza enceliae Spencer, on Encelia farinosa; 39: Calycomyza smallanthi spec. nov., on Smallanthus uvedalius, young mine with evident linear portion; 40: same, young mine containing several larvae; 41: the same mine, complete and vacated; 42: Cerodontha (Icteromyza) longipennis (Loew), on Carex pseudocyperus; 43: same (detail showing puparium in transmitted light); 44: Liriomyza euphorbiella spec. nov., on Euphorbia cyathophora (reflected light); 45: same (transmitted light).