APHIS AMYGDALI. 105 



the bases of the cornicles. Wing-cases pale green. 

 Legs and antenna© pale brown. 



Winged viviparous female. 



Rusty yellow. Head, thorax, antennEe, and band 

 on the prothorax dark brown or black. Abdomen 

 smooth, domed, with a row of small spots on each 

 lateral edge, and a large brown spot covering the 

 lower portion of the dorsum. Nectaries straight, 

 rather thicker at their bases. Legs dark ochreous, 

 with black femoral and tibial points. Wings broad 

 and rounded ; insertions and stigmata pale ochreous ; 

 veins fine and brown. The two anal rings show un- 

 derneath four small papillas, and one larger one, which 

 last represents the tail. 



The new-born young are entirely yellow, except that 

 two broad brown spots mark the head, and five or six 

 longitudinal minute dots show the incipient deposition 

 of dark pigment on the abdomen. The occurrence of 

 this pigment is very inconstant, being sparing in the 

 younger individuals, but often in the older ones 

 covering the whole insects, so as to make them appear 

 black. 



This Aphis is perhaps the chief insect-pest on our 

 peach and nectarine trees, causing the leaves to curl 

 and drop, so as finally to leave the branches bare, and 

 leafless. In Italy this diseased state is known as 

 " fillorissema del pesco." This Aphis, however, does 

 not cause the fleshy degeneration and mouldiness of 

 the foliage so commonly seen, which is the effect of 

 the mycelium of the fungus Exoaseus deformans of 

 Berkley. 



The specimens figured were taken from many 



