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pale bristles, and thickly set with short dark scales, which change toward tlie 

 apex into short, spreading, papillose setae. Anal plates not smooth, but im- 

 bricate like the style and bearing a fringe of long pale bristles. Body smooth, 

 rather thick set and compact; length 1.96 mm. to 2.09 mm.; breadth wing to 

 wing 6.54 mm. to 7.25 mm.; wing 2.73 mm. to 3.18 mm. 



April to June. Leaves and twigs of the peach. 

 Apterous vivip.\rous female [pseiidogyiia fundatrix? and pseudo- 

 g-yna gcnunans). — Antennas variable, usually about two-thirds the length of 

 the body, black or dark brown, set on widely separate, inconspicuous, frontal 

 tubercles; joints not tuberculate, vii almost always shorter than iii; no sen- 

 soria on iii or iv, one on distal end of v, and a group on the e.xpanded distal 

 end of vi. Beak reaching to second pair of coxce and sometimes beyond, 

 but not to third pair, except in immature specimens (0.53 mm. to 0.82 mm.). 

 Thorax broad and flat, gradually widening posteriorly and blending with the 

 very broad abdomen into a smooth and shining black plate, in which the 

 separate segments are indistinguishable. Abdomen margined, broader than 

 long, rounded behind, so that the insect is broad wedge form, sometimes 

 almost cordate, especially when distended with pseudova. Abdominal seg- 

 ments distinct beneath, but usually only the last 2 — 3 visible above; venter, 

 and sometimes border of dorsum, dark coffee-brown, the rest very black and 

 shining, as if lacquered; sometimes a row of pits or depressions along the 

 margins, corresponding to the stigmata, dorsum not otherwise pitted and free 

 from hairs, tubercles, or mealiness. Length of body 1.64 mm. to 2.38 mm.; 

 breadth'i.oo mm. to 1.50 mm. 



In all other particulars like the winged form. The young are 

 a uniform pale yellow or weak-coffee color, becoming darker with 

 each moult. The insect bears no green or greenish markings at any 

 stage of development. . 



January to December. All parts of the peach tree above ground 

 and below. Commonest upon the branches from early spring to 

 midsummer, but also observed in autumn and twice in midwinter 

 (January, 1889, and January and February, 1890). Can be found 

 upon the roots almost always at any time of year. 



Habitat. — Virginia (!), Maryland (!), Delaware (!), New Jersey, 

 Michigan (!). 



Very abundant and destructive along the Atlantic coast, but 

 rare in the West, as if recently introduced. 



This aphis has been known tp peach growers for more than 

 twenty years, but does not appear to have been critically studied by 

 any one. It has been identified with Myzus persicce (Sulzer), which 

 it does not resemble, and with Myziis cerasi (Fab.), which it resem- 

 bles only superficially. Prof Uhler thought it agreed most nearly 

 with Koch's description of ^. chrysanthemi, and in my first account 

 of the insect* I followed his judgment, not having seen the winged 



* Peach Yellows: A prcliuiinary Report, U. S. Dept. of Agric. 1889. 



