42 Mr. F. Walker's Descriptions of Aphides. 



tips of the shanks are brown. On Stachys sylvatica at the end 

 of April. 



The viviparous winded female. Is black : the abdomen is dark 

 green ; the segments have black borders : the feelers are much 

 shorter than the body : the mouth is paler towards the base : the 

 nectaries are hardly more than one-twelfth of the length of the 

 body : the legs are black ; the shanks excepting their tips are 

 yellow : the wings are colourless and very much longer than the 

 body ; the wing-ribs and the rib-veins are pale yellow ; the wing- 

 brands and the veins are pale brown ; the second vein diverges a 

 little more from the first than it does from the third ; the first 

 fork of the latter vein usually begins after one-third, and the 

 second long after two-thirds of the length of the vein ; the fourth 

 vein is moderately curved, and the angle of the vein whence it 

 springs is extremely slight. In the autumn. 



1st var. The mouth is dull green with a black tip : the nec- 

 taries are about one-sixth of the length of the body : the thighs 

 are yellow towards the base : the wing-ribs are pale green ; the 

 veins are brown. At the end of May. 



2nd var. The abdomen is very dark green : the feelers are as 

 long as the body : the mouth is dull yellow, but black towards 

 its tip : the nectaries are hardly one-sixth of the length of the 

 body : the fore-thighs are dark yellow towards the base. In the 

 middle of October. 



3rd var. The body is black : the borders and the underside of 

 the fore-chest and the abdomen are dark green : the feelers are as 

 long as the body : the mouth and the nectaries are dull yellow 

 with black tips, and the latter are as long as one-fourth of the 

 body : the thighs are pale yellow at the base : the wing-veins are 

 brown. 



Length of the body ^-| line ; of the wings 2^-2^ lines. 



When it feeds on the bramble it is larger and paler than when 

 it feeds on the nettle, and is much resorted to by Formica fusca. 



67. Aphis tetrarhoda, n. s. 



The viviparous wingless female. This species feeds on the rose, 

 and when full-grown is deep green, oval, very convex and plump, 

 and covered beneath with a white bloom ; it is bristly and has 

 six rows of tubercles on the back, and the middle rows are very 

 distinct : the front is hardly notched : the feelers are nearly half 

 the length of the body : the eyes are dark red : the nectaries 

 have brown tips, and are about one-eighth of the length of the 

 body : the legs are dark green, and rather long ; the feet and the 

 tips of the shanks are brown. When young it is pale grass-green, 

 slightly convex, and has a rim on each side, but its tubercles arc 

 indistinct : the feelers are about half the length of the body. 



