Agromyzidae

Eiseman, Charles S. & Lonsdale, Owen, 2018, New state and host records for Agromyzidae (Diptera) in the United States, with the description of thirty new species, Zootaxa 4479 (1), pp. 1-156 : 95

Agromyzidae sp. 1

( Fig. 224 )

Material examined. COLORADO: Pitkin Co., Aspen, Discovery Trail (off Hwy 82, 10,400 feet elev.), 12.vii.2015, em. 25.vii.2015, C.S. Eiseman, ex Arnica ? cordifolia , #CSE1826, CNC 564632 (1♀, body almost entirely obscured); same collection, em. by 27.vii.2015, #CSE1871.

Host. Asteraceae : Arnica L.

Leaf mine. ( Fig. 224 ) Whitish, entirely linear; largely on the upper surface, but with sections on the lower surface, giving the mine a broken appearance; frass in long, black strips along the sides.

Puparium. White or rarely brown (parasitized?), formed within the leaf in a transparent blister on the lower surface, its anterior spiracles projecting ventrally through the lower epidermis.

Comments. These poor specimens could not be identified to genus. Seven Nearctic agromyzids are recorded from Arnica , all of them Phytomyza species covered by Griffiths (1974b). Four are members of the P. albiceps group that pupate externally. The remaining three are members of the P. ciliata group known only from Alaska and western Canada; all have a white puparium formed on the lower leaf surface as in our species. Of these, P. campestris Griffiths deposits frass in particles mostly separated by over 1 mm; P. arnicivora Sehgal mostly in beaded strips; and P. oreas Griffiths in narrowly separated particles or beaded strips. Mines of P. oreas are entirely on the upper leaf surface or with a short terminal channel on the lower surface leading to the pupation site; those of P. arnicivora in most cases are partly or largely on the lower surface. Thus, of the known Arnica miners, the Colorado species most closely matches P. arnicivora in its leaf mine characteristics. Spencer (1981) reported mines on A. chamissonis Less. in California that may have been made by either P. arnicivora or P. oreas .

Figures

FIGURES 217–224. leaf mines; 217: Phytomyza sp. 1 in Sium suave; 218: Phytomyza sp. 2 in Symphyotrichum lateriflorum; 219: Phytomyza sp. 3 in Lonicera canadensis (puparium at leaf base, far left); 220: Phytomyza sp. 4 in Symphoricarpos orbiculatus (puparium toward top of photo); 221: Phytomyza sp. 5 in Caltha palustris; 222: Phytomyza sp. 6 in Trautvetteria caroliniensis; 223: Phytomyza sp. 7 in Tiarella trifoliata var. unifoliata; 224: Agromyzidae sp. 1. in Arnica?cordifolia.