339 
Mr. F. Walker^s Descriptions Aphides. 
4th variety. Bright yellow, having a brown line along the head 
and the ehest, and a line of the same eolour on each side of the 
latter, which has also a small brown spot at its tip : there are 
four rows of brown spots on the abdomen : the tips of the shanks 
are brown. , 
During the summer it has many other tints of yellow and of 
green, more or less varied wuth brown and black. During the 
spring of 1846 I found it in abundance feeding on the dwarf 
chestnut [Castanea pumila) , a native of America, but with this 
exception the oak seems to be its only support. 
There are two other varieties of A. Quercus : in the first the 
body is rather short and nearly linear, and the head is as broad 
as the chest ; in the second the body is longer, and increasing in 
breadth from the head till near the tip of the abdomen, and the 
head is narrower than the chest. 
The oviparous wingless female. Its season is from the middle 
of October to the end of November : the variableness of its colour 
is partly owing to the orange eggs which it incloses : it is often 
bright yellow and has a lively green stripe on each side of the 
body : the abdomen is not a little lengthened behind : the feelers 
are pale yellow ; the tips of the joints are black : the legs are 
pale yellow ; the hind-shanks sometimes and especially towards 
the base are slightly dilated, and of a rather darker colour than 
the other shanks. 
1st variety. Yellowish green. 
2nd variety. Pale orange. 
3rd variety. Brilliant orange with a pale yellow or pale green 
head. It has also various tints of green and of yellow. 
The body slightly increases in breadth from the head till near 
the tip of the abdomen : the feelers are much shorter than the 
body : the front of the head is beset with bristles : the sides of 
the fore-chest are not notched : the legs are rather short. 
The winged male. It appears in the autumn, and pairs with 
the oviparous wingless female in October : it is grass-green : the 
disc of the chest is black, and there is a broad black line along 
the disc of the abdomen : the feelers and the eyes are black, and 
the former are longer than the body; the fourth joint is much 
shorter than the third ; the fifth is shorter than the fourth ; the 
sixth is much shorter than the fifth ; the seventh is a little longer 
than the sixth : the legs are pale yellow ; the thighs are pale 
green, and with the exception of the fore-thighs they are shaded 
with black. 
1st variety. BulF : the abdomen is dull buff marked with black, 
and has a row of black spots on each side : the nectaries are also 
black. 
The wing-veins are much more strongly marked than those of 
23* 
