44 Mr. F. Walker^s Desci'iptions of Aphides. 



more or less yellow^ and the latter are sometimes white. It 

 swarms on the young shoots, which may be easily cut off and 

 removed with all their inhabitants : the leaves which it infests 

 become twisted, curled, and glutinous, and are often shed. It is 

 infested by an Aphidius and by an Allotria. The front is nearly 

 straight with a very distinct tubercle on each side : the feelers are 

 sometimes about half the length of the body ; the fourth joint is 

 more than half the length of the third ; the fifth is much shorter 

 than the fourth ; the sixth is much shorter than the fifth, though 

 more than half its length ; the seventh is about thrice the length 

 of the sixth. 



The viviparous winged female. This while a pupa is dark red : 

 the feelers, the feet, and the tips of the four hinder thighs and 

 of the shanks are brown ; the feelers at the base and the legs 

 with the above exceptions are yellow. The wings are unfolded in 

 the beginning of June, and the insect is then black and shining : 

 the borders of the fore-chest are dark red : the abdomen is dark 

 brown : the feelers are as long as the bodj'^, and the nectaries are 

 equal to one-sixth of its length : the mouth is pale yellow with a 

 brown tip : the thighs towards the base and the shanks are yel- 

 low : the wings are colourless, and much longer than the body ; 

 the wing-ribs are pale yellow ; the wing-brands are pale brown, 

 and the veins are darker ; the second vein diverges more from the 

 first than it does from the third ; the first fork of the latter begins 

 before or at one-third, and the second fork at or after two-thirds 

 of its length ; the fourth vein is much curved near its source, 

 but nearly straight in the latter part of its course; the angle 

 whence it springs is very slight. The wings are milk-white for 

 a while after they have been unfolded, and then the other limbs 

 are also white, and the body is pale reddish brown. The fore- 

 legs are considerably shorter than the hind-legs ; the shanks are 

 straight. 



Variation in the wing-veins. The lower branch of the second 

 fork is wanting. 



The oviparous wingless female. This occurs in the middle of 

 November : it is black, elliptical, and much smaller and narrower 

 than the viviparous female : the feelers are rather more than half 

 the length of the body ; the fifth joint is hardly shorter than the 

 fourth ; the seventh is nearly twice the length of the sixth : the 

 abdomen is slightly produced at the tip, and has two plates 

 beneath like those of A. Tilice : the legs are rather short and 

 stout ; the hind-shanks are not dilated. The glutinous matter 

 which covers its body when mixed with Canada balsam acquires 

 a delicate green colour. 



The winged male. This resembles the winged female, but pairs 

 with the oviparous female in November. The sixth joint of the 



