AGROMYZID LEAF MINERS — FRICK 385 



gites laterally black or brown; the basal two or three tergites of P. (D.) 

 morosa are laterally yellow. The head (fig. 80) and wing (fig. 81) of 

 the holotype male are illustrated in order to help identify this pre- 

 viously misidentified species. The larval host plants are not known. 

 I have seen specimens from Illinois, Indiana, Michigan, District of 

 Columbia, Pennsylvania, and New Hampshire as well as from British 

 Columbia. 



Phytobia (Dizygomyza) morosa (Meigen) 



Agromyza morosa Meigen, Systematische Beschreibung der bekannten euro- 



paischen zweifliigeligen Insekten, vol. 6, p. 170, 1830. 

 Dizygomyza {Dizygomyza) morosa (Meigen), Hendel, in Lindner, Die Fliegen der 



palaearktischen Region, fam. 59, p. 90, 1931 (figures of head and puparial 



spiracles). 

 Another Holarctic species that is little known in North America. 

 It is distinctive in having the basal two or three tergites yellow later- 

 ally. No larval host plants are known in North America but the 

 larvae mine in species of Scirpus and Carex in Europe. Thus far 

 known only from South Dakota, Illinois, Indiana, and Maryland. 



Phytobia (Dizygomyza) thompsoni Frick 



Agromyza magnicornis (Loew), Coquillett, in Thompson, Psyche, vol. 14, p. 74, 



1907 (figure of leaf galls). 

 Agromyza laterella (Zetterstedt), Malloch (part), Ann. Ent. Soc. Amer., vol. 6, 



p. 300, 1913. — Claassen, Ann. Ent. Soc. Amer., vol. 11, p. 9, 1918 (figures of 



adult, puparium, larva, and leaf mines and galls). 



This is a large species (2.75 to 3 mm. in wing length) for a species of 

 the subgenus Dizygomyza. The head is subtriangular in profile with 

 the genovertical plates strongly extending beyond the eye margin (fig. 

 82). The lunule is high for this subgenus, extending halfway to the 

 anterior ocellus from the antennal base (fig. 83) . The male terminalia 

 is characterized by the large yellow knob on the ninth tergite (fig. 84). 

 The larvae miue the leaves of Iris versicolor L., Iris sp. (blue flag), 

 and Typha spp. There are specimens from Illinois, Michigan, Penn- 

 sylvania, New York, and Massachusetts. 



5g. Subgenus Icteromyza Hendel 



Icteromyza Hendel, in Lindner, Die Fliegen der palaearktischen Region, fam. 59, 

 p. 51, 1931. 



The adults are characterized by the bright yellow frontal vitta and 

 lunule, the elongate frontal triangle reaching to the lunule, the very 

 large lunule that is in the plane of the frontal vitta and abruptly 

 raised above the mesofacial plate, and the widely spaced antennal 

 bases (fig. 85). This subgenus may be separated from subgenus 

 Poemyza by the bright yellow frontal vitta and the lunule in the plane 

 of the frontal vitta and from subgenus Dizygomyza by the color of 



