April, '08] JOURNAL OF ECONOMIC ENTOMOLOGY 85 



tree. The specimens you sent April 30 and May 7 from peach all have 

 cornicles cylindrical. The fall migrants and the specimens sent from 

 tomato and turnips early in the summer all have clavate cornicles in 

 the winged form. * * * The distinguishing character of this 

 species for the winged individuals seem to be : Antenna longer than 

 the body upon pronounced frontal tubercles which are quite approxi- 

 mate, second joint of antenna moderately gibbus, third joint with sen- 

 soria on the ventral side only and a large dark patch upon the dorsum 

 of the abdomen anterior to the cornicles, and during the late part of 

 the season the cornicle moderately clavate in the winged forms." 



A point brought out by the foregoing is that the large per cent, 

 of the descriptions of this and related species were made from speci- 

 mens taken in the fall. I have recently had an opportunity to go over 

 with Mr. J. T. Monell of St. Louis some accession records of collec- 

 tions of this species made during a period of about thirty years and 

 the majority were found to have been made in the fall. In fact but 

 a single exception to this was found, which was in the case of the 

 species given by Mr. Pergande as Aphis persicae Sulz., and taken by 

 him in St. Louis in May, 1879. 



I have found in "Western Colorado the eggs or stem-mothers of 

 Myziis persicae Sulz. upon peach and plum and the lice have been 

 found in that state at different times upon peach, nectarine, plum, 

 prune, cherry, choke-cherry, sand-cherry and more rarely upon pear, 

 apple, crab-apple, willow and cultivated rose. Also the following 

 herbaceous plants have been found as host plants at some seasons of 

 the year: Turnip, rape, cabbage, tomato, potato, false-mallow {Mal- 

 vastrum sp.) yellow-dock, red-root {Amarantus sp.) mustard, shep- 

 herd 's-purse, snap-dragon, carnation, rhubarb and egg-plant. In not 

 every instance upon the plants given were the pink or salmon-colored 

 lice present, although the collections were sometimes made in the 

 spring or fall when this form would have been expected. This leaves 

 perhaps a possibility of other species being mistaken for this one un- 

 less the kind of food plant had affected the coloration of the louse. 

 Mr. Monell recently showed me two samples of what seemed to be this 

 species taken by him November 2-4, 1907, at Shaw's Garden, St. Louis, 

 one from cabbage and one from peach. Both cases showed the winged 

 forms with slightly dilate cornicles and otherwise appearing the same, 

 but none of the lice upon the cabbage showed the salmon color, though 

 they were abundant upon the peach leaves at that time. 



In this paper I have designated this insect as the green peach-aphis, 

 to distinguish it from the black peach-aphis, with which it is sometimes 

 confused. It is very different from the latter, however, which has in 



