132 CHERRY. LEAVES CHERRY PLANT-LOUSE. 



least at their ends; the neck and lower side of the head are green ; the an- 

 tennae are two-thirds of the length of the body, dusky, and in young indivi- 

 duals green at their bases; the beak is short, pale green, its apex blackish; the 

 legs are dull white, the feet and four hind thighs except at their base, blackish; 

 the wings are pellucid, the stigina salt white margined with dusk}^, more wide- 

 ly so on its inner side, the veins black, the rib-vein white, the second fork very 

 short. 



The wingless female are 0.08 long, egg-shaped, pale yellowish green, their 

 abdomens coated with a white meal-like powder except at the sutures and on 

 the medial lines, which last is deeper green, and the legs and antennae dull 

 white. 



The larva when young are pea green with white antennas, nectaries and legs. 

 When older a deeper green stripe appears along the middle of the back and a 

 row of deeper green spots each side which are more or less confluent into 

 stripes. 



The aphis upon our garden cherry is the species which is named 

 Jlphis Cerasi by Fabricius. It undoubtedly has been introduced 

 upon this side of the Atlantic with the tree which it infests. M. 

 Fonscolomb (Annals Ent. Soc. x. 173), speaking of this species 

 in the southern part of France, says it occurs the last of July, 

 and that he has never met with any winged individuals. This 

 would indicate the species to be much more rare than it is with 

 us. Here from the middle of May till the last of September it is 

 the most common of any species of this family. For years when 

 I have wished to investigate any fact in connection with the 

 aphides I have turned to this species, always finding it at hand, 

 and always with two or three winged individuals upon every leaf, 

 in company with larvae, pupse and wingless females. 



The lakvje when newly born are about 0.03 long, of a dull white or pale 

 yellow color, with transparent and colorless legs and antennae. They are of 

 an oblong oval form, with the opposite sides of their bodies parallel and their 

 nectaries shorter than to the tip and transparent or slightly dusky. As they 

 become larger they are broader across the abdomen and deeper yellow, the 

 tips of the antennae and the feet dusky and the nectaries black. After casting 

 their skins they are dull reddish brown or chestnut colored with black heads, 

 and are much broader across the abdomen, being now shaped like an egg and 

 measuring 0.05 in length. Their legs, antennae and nectaries are whitish 

 transparent, the last equalling the tip. Others of this same size and form 

 have the thighs, feet, nectaries and tips of the antennae dusky. 



The wingless females are 0.05 long, with very plump broad egg-shaped 

 bodies, which are black and shining, with a slightly projecting tail, the nec- 

 taries equalling or even surpassing its tip and of a black color, the antennas 

 shorter than the body and whitish, their two short basal joints and the apical 

 half black; the beak whitish with a hlack tip; the legs white with the feet, 



