Mr. P. Walker's Descriptions of Aphides. 337 



tuse angle or a curved line along the lower border of the brand 

 which it incloses : the branch-veins are nearly straight ; the third 

 vein approaches very near to the main vein ; it is forked at one- 

 third, and forked again at two-thirds of its length. 



The oviparous wingless female. This appears in October, and 

 continues beneath the leaves till the end of November ; it is often 

 orange, and this colour is owing to its eggs, which are attached 

 to the twigs in November. 



12. Aphis Quercus, Kaltenbach. 



Aphis Quercus, Kalt. Mon. Pilan. i. 98. 74 ; Ratzeburg, Forst. 

 Ins. iii. 217. 



This and A. Quercea are very pretty, and great ornaments to 

 the oaks on which they feed ; they have a mutual likeness, but 

 may be distinguished from each other by the following charac- 

 teristics : the colour of A. Quercus is usually green, yellow, or 

 orange ; the feelers are never much longer than the body, and 

 the nectaries have black tips ; A. Quercea has a rosy hue, its 

 feelers are much longer than the body, there are two hooks on 

 the back of its abdomen, and black spots on the tips of its thighs. 



The front of A. Quercus is nearly straight, or slightly notched ; 

 there are no tubercles at the base of the feelers, whose fourth 

 joint is much shorter than the third ; the fifth is still shorter 

 than the fourth ; the sixth is nearly half the length of the fifth ; 

 the seventh is longer than the sixth : the fore-chest is subqua- 

 drate, rather narrower in front ; its breadth slightly exceeds its 

 length ; the sides are undulated. The feelers vary in length, but 

 are usually longer than the body ; the fifth joint is sometimes as 

 long as the fourth, and the sixth full half the length of the fifth, 

 and the seventh but very little longer than the sixth. It differs 

 from A. Quercea in its broader head and front, in its shorter legs, in 

 having no horn or hooks on the abdomen, in the broad black tips 

 of each joint of its feelers, and in its black -tipped nectaries : the 

 sides of the fore-chest are sometimes nearly straight : the wing- 

 veins are more straight than those of A. Quercea ; the main vein, 

 somewhat beyond the middle of the fore-border, expands into a 

 yellow irregularly spindle-shaped brand, which has a dark spot 

 at its base ; the angle formed by the vein on the lower border of 

 this brand is much more obtuse than that of A. Quercea : the 

 thighs are not spotted : the first branch-vein is more perpendicu- 

 lar to the main vein than is that of A. Quercea : the front of the 

 head is often a little notched, and armed with bristles. 



The viviparous wingless female. This appears at the end of 

 April or later : it is then pale yellow, very small, narrow and 

 linear, and has four rows of brown spots along the back, each of 

 them sending forth a bristle : the feelers are stout, dull brown, 



Ann. £$ Mag. N. Hist. Ser. 2. Vol.i. 23 



