AGROMYZID LEAF MINERS — FRICK 397 



Phytobia (Xenophytomyza) illinoensis (Mallocb) 



Agromyza illinoensis Malloch, Diptera of Patagonia and South Chile, pt. 6, 



fasc. 5, p. 483, 1934. 

 Cerodontha (Xenophytomyza) illinoensis (Malloch), Frick, Journ. Kansas Ent. 



Soc, vol. 25, p. 151, 1952 (figure of head). 



A dark robust species having a blunt angle distally on the third 

 antennal segment. It is most easily separated from the dark Phytobia 

 species by the single pan* of scutellar setae. It is known from swept 

 specimens from Illinois and Virginia. 



7. Genus Liriornyza Mils. , ., 



Liriomyza Mik, Wiener Ent. Zeit., vol. 13, p. 289, 1894. 



The genus Liriomyza is large, with 35 described North American 

 species. Of these, 30 are Nearctic, four are Neotropical, and one is 

 found in both regions. SLx are Holarctic in distribution. 



This genus is characterized by the partially or totally yellow scutel- 

 lum, vein Mi+o being at or very near the wing tip (fig. 108), and the 

 orbital setulae reclinate (fig. 107) or erect (fig. 110). There are usually 

 numerous orbital setulae but they may be very sparse (fig. 112). 

 Most of the species have some yellow on the head or body. There 

 are a few that are as over-all dark as some species included in Meto- 

 pomyza. The genovertical plates are narrower in Liriomyza species 

 (the widest is shown in fig. 104) . These plates are very broad thi'ough- 

 out their full length in species of Metopomyza (fig. 128). There are 

 no setae medially on the midtibia except for Liriomyza braziliensis 

 (Frost) and L. ecuadorensis (Frost). 



Although Liriomyza and Haplomyza appear to be separated on 

 rather superficial characters in the key, the separation is justified 

 by the two widely divergent types of male terminalia and larvae 

 found in the two genera. Certain European species of Liriomyza 

 have as many as three of the Haplomyza characters; e. g., if the mes- 

 onotum is heavily gray pollinose and there are two rows of acrostichals 

 and only one upper-orbital, then crossvein m-m is present. In 

 North America, two Haplomyza characters may occur together. As 

 an example, Liriomyza assimilis has the mesonotum dull gray pollinose 

 and has only two rows of acrostichals (fig. 99), but crossvein m-m 

 is present and there are two upper-orbitals (fig. 98). Crossvein 

 m-m is absent in L. chlamydata but the mesonotum is shining and 

 bears four rows of acrostichals and there are two reclinate upper- 

 orbitals. 



Several unusual characters might be briefly mentioned here. The 

 sorosis group is unusual in having either two postsutural dorsocentrals 

 (fig. Ill) or three with the thu'd anterior to the supraalar seta and 



