STATE HORTICULTURAL SOCIETY. 159 



apple tree. It is found on the under side of the leaves of our native and 

 cultivated plums, wrinkling and destroying them. What is said in refer- 

 ence to the history of the Apple Plant-louse will apply, as a general rule, 

 to this species, which does not appear to abound to the same extent as 

 some of the species already named. 



The species appears to be quite variable, but the following, taken 

 chiefly from the original description by the author of the species, will 

 probably enable the reader to identify it : 



The winged specimens measure about one-seventh of an inch to the 

 tip of the wings: the body is of a shining black, except the abdomen, 

 which is pale green with a black dot on each side of the middle of the 

 two or three anterior segments ; a large dusky spot rather behind the 

 middle; tip of the abdomen acuminate; honey-tubes cylindrical, reach- 

 ing* to the tip of the abdomen. The legs are pale, dull yellowish; 

 antennas black, except at the base, where they are pale. Wings pellucid; 

 veins dusky, except the rib-vein. The venation does not appear to be as 

 uniform as is usually the case in this genus. 



The larvK are more or less of a greenish-white color, varying accord- 

 ing to age. The wingless specimens are oval in form ; the average length 

 about one-sixteenth of an inch. 



It is possible that this species is but a variety of A. pnini, Fab., of 

 Europe, produced from imported individuals; but the fact that it is found 

 on our native plums, as well as cultivated varieties, and some marked 

 differences, certainly justify Dr. Fitch in considering it as distinct. 



In addition to what he has said, I may add that a more recent de- 

 scription oi A. pruni, as found in France, given by Goureau, states that 

 the head and thorax are brown, and covered with white powder, which cor- 

 responds exactly with Amyot's description. But there appears to be no 

 difference between the larvae of the two species, except the difference in 

 the length of the honey-tubes, which in A. pruni^x^ short, not reaching 

 to the tip of the abdomen. 



19. Aphis persicce, Sulz. The Peach-tree Plant-louse. 



The Peach-tree Aphis of this country, which is probably the same as 

 that found on peach trees in Europe, lives on the underside of the leaves 

 of the peach tree, to which it appears to be confined, causing them to be 

 thickened; to curl and form hollows beneath, and corresponding crispy 

 swellings above, and ultimately perish and drop off prematurely. 



The length of the body is about one-twelfth of an inch ; length to 

 tip of the wings, about one-sixth of an inch. The body is greenish-black, 

 with black markings ; antennae, black ; abdomen, brownish-yellow, with 

 irregular black markings; legs, brownish-yellow ; wings, pellucid. 



20. Aphis amygdali, Blanch. The Almond Plant-louse. 



This species, which is much smaller than the preceding, is found 



* Note. — This expression is used simply to denote that these tubes are as long as the distance 

 from their base to the tip of the abdomen, and not that literally they "reach the tip." 



