54 APPLE LEAVES, PLANT-LOUSE — DESCRIPTION. 



shining appearance, as though they were coated with varnish, 

 For the purpose of regaling themselves upon this honey dew, or 

 to destroy the aphides, different species of ants, flies, and quite a 

 number of other insects are always found in company with them. 

 Several of these, and their habits, will be more particularly con- 

 sidered at the close of our account of this species. 



Grouped together, and covering the surface of the twigs and 

 leaves which they infest, these lice are found in all stages of their 

 growth. When newly born they are almost white, but soon be- 

 come pale dull greenish yellow, which is their prevailing color 

 during the larva period of their lives, the antennae, the nectaries, 

 the knees and feet being dusky, and sometimes black. The ma- 

 ture females are generally without wings, and their bodies are 

 much broader than in the larva state, being shaped like an egg, 

 the smaller end forward. These, as well as the winged indivi- 

 duals, vary greatly in their colors and marks, as will be seen 

 from the description of this species and its varieties which we 

 here give. 



The wingless females are somewhat less than the tenth of an inch long, 

 and are of a pale yellowish green color, with the head frequently more yellow 

 than the body. Stripes of a deep green color are commonly present upon the 

 back, or sometimes there is a single stripe in the middle, and transverse ones 

 at each of the sutures or impressed lines between the segments, but these trans- 

 verse stripes do not extend to the margin upon either side. The eyes are black. 

 The beak, by which it pierces and sucks the juices of the twigs and leaves, 

 the antennae, and the legs, are whitish, their tips black or dusky, and the 

 knees also are commonly dusky. The nectaries are equal in length to the dis- 

 tance from their bases to the tip of the abdomen, and are dusky or white, with 

 their outer ends black. Protruding from the extremity of the abdomen, is a 

 short tail-like appendage, nearly half as long as the nectaries, and of a black 

 color. But in females examined in autumn, at the time of depositing their 

 eggs, this appendage was not observed. I hence infer it pertains only to those 

 which bear living young. 



The males and the winged females appear to be alike in their colors. They 

 measure about 0.12 to the tips of the wings, this being double the length to 

 the tip of the abdomen, or more. The head and thorax are of a coal black 

 color, with the neck commonly green. The antennas are inserted upon the 

 front part of the head, between the eyes. They are black, slightly tapering 

 towards their tips, scarcely as long as the body, and slightly covered with very 

 fine short hairs. They are seven-jointed, the two basal joints short and thick, 

 almost as broad as long; the third joint is longest of all, and often shows seve- 

 ral slight equidistant constrictions, dividing it seemingly into several 

 short joints; the fourth and fifth joints are equal, and each but little 



