350 



like that of parvicornis; female ovipositor very conspicuous, as long as 

 preceding segment of abdomen, of almost equal diameter throughout 

 its length; surface with short hairs (PI. LXXXIV, Fig. ii). Legs of 

 moderate strength; mid-tibial bristles small. Wings of moderate 

 width ; costa to slightly beyond apex of third vein ; inner cross-vein be- 

 low end of first vein; outer cross-vein less than its own length from 

 inner, slightly bent, its upper extremity nearer apex of wing than its 

 lower; last section of fourth vein about lO times as long as preceding 

 section; last section of fifth about lY^ times as long as preceding sec- 

 tion. 



Length, 3.5-4 mm. 



The life history of this species has been dealt with by its describer 

 in the bulletin cited under the species name in the present paper, it being 

 an elaboration of his report upon the same species in a previous paper.* 



The three species of Agromysa known to cause medullary spots in 

 wood of trees are carbonaria Zetterstedt, a European species; pruinosa 

 Cocjuillett, occurring in the cambium of river birch; and the present 

 species, found in the cambium of Primus avium and domestica. In 

 Grossenbacher's first paper above cited he states that Cratccgus is also 

 attacked, while Salix is not. In his last paper he makes mention only 

 of the species of Prumis, and gives his agromyzid a name that leads me 

 to infer that he considers it as a Prunus-in testing species exclusively. 



I have recorded Agromyza pruinosa from Illinoisf, and it is very 

 probable that A. pruiii occurs in suitable localities. Up to the present 

 I have been unable to devote time to a search for the species. 



I have drawn the larva and puparium of Agromysa parvicornis 

 Loew (PI. LXXXIV, Figs. 14 and 15) to show the normal reduction 

 in size due to the induration of the larval skin in pupation in Agromysa. 



The imago of pruni will run down to section 16 in my key to the 

 North American species of this genus| if the frons is considered as 

 partlv reddish, the cross veins being close together. It is readily sepa- 

 rated from both of the species in that section by its robust build and 

 the possession of 4 pairs of dorso-central bristles. The species has 

 much the same appearance as pruinosa, but differs in venation, etc., 

 while the food plant and larval and pupal characters are quite enough 

 to separate them specifically. The difference in venation will separate 

 it from aprilina. 



^Medullary spots : a contribution to the life history of some cambium miners. 

 Tech. Bull. 15, N. Y. Agr. Exper, Sta., pp. 47-65. 1910.* 

 tCan. Ent., Vol. 47, 1915, p. 15. 

 tAnn. Ent. Soc. Amer., Vol. 6, 1913, p. 271. 



