BULLETIN 267 



THE APHID OF CHOKE CHERRY AND GRAIN. 1 



Aphis pseudoavenae sp. n. 

 EDITH M. PATCH. 



Late in June, 1917, a group of choke cherries on the campus 

 of the University of Maine were found to be heavily infested 

 with a species of aphid which I had not previously taken, although 

 specimens of the same thing were brought me from Fort Kent, 

 Maine, July 6, 1916 where they were found by Professor C. L. 

 Metcalf while collecting syrphids. 



Mounted specimens of this aphid would be most likely to 

 be determined as Aphis avcnac (i. e. of American authors) 

 because of the constriction before the flange of the cornicle, the 

 arrangement of the sensoria of the antennae, and the rather long, 

 pointed stigma and the noticeably short second branch of M in 

 the wing. 



However, the fresh colonies crowded close along the stem 

 and ventral leaf would suggest at once the Aphis rumicis group 

 on acount of the conspicuous areas of wax powder, and could 

 not be mistaken for avenae in life. 



DESCRIPTION FROM LIFE. 

 SPRING CHOKE CHJERRY GENERATIONS. 



Apterous viviparous female : A rather old individual had 

 body dark olive green irregularly mottled with still darker. 

 Areas of powder especially noticeable in lateral rows of spots 

 on abdomen, one on each side of segments just dorsad of promi- 

 nent lateral crease, and over the tip of the abdomen caudad 

 cornicles. These white areas are conspicuous on undisturbed 

 colony but the powder is soon shaken off from collected material 

 and then the aphids show only a general rather slight pulverul- 



Tapers from the Maine Agricultural Experiment Station: Entomol- 

 ogy No. 95. 



