14 Farmers’ Bulletin 1128. 
Another species, which is slaty blue or black, with white bands 
upon the legs, and often possesses white waxy tufts, occurs sometimes 
upon the apple. This is the dock aphis.!. The apple does not seem 
to furnish suitable food to these insects, for after a few generations 
they always leave the trees. 
A second dark brown or blackish 
species which occurs occasionally 
upon the apple is the bur-clover 
aphis.2 It is sometimes encoun- 
tered during the spring upon 
apple foliage. 
Still another species, the wild- 
carrot aphis,? occurs commonly on 
the apple in the fall, particularly 
as the winged form. Its summer 
hosts are the wild carrot and re- 
lated plants, and the winged forms 
fly to honeysuckle vines, but 
occasionally select apple trees. 
The thorn-leaf aphis‘ also is 
found occasionally upon the apple. 
Its life history is discussed under 
aphids attacking the quince. 
QUINCE APHIDS. 
Two species of aphids which 
have been discussed under apple 
occur commonly also upon quince 
foliage—namely, the green apple 
aphis and the apple-grain aphis. 
Their life histories are similar on 
quince and apple, and the same 
remedial measures apply. 
THE THORN-LEAF APHIS. 
The thorn-leaf aphis,* called also 
the long-beaked clover aphis, is 
most common upon hawthorn 
trees. Although first found upon 
thorn, it is not uncommon upon 
Fig. 8.—The wooly apple sie Colonies on quince leaves. It resembles very 
apple shoots, P 
closely the clover aphis as found 
upon apple, but can be distinguished from that insect by its long beak. 
On thorn trees the feeding of this species results in a curling of the 
leaves which is very conspicuous, the twisted leaves taking on a 
purplish cast. On quinces, however, it does not curl the leaves, or 
at least not to such an extent. 
1 Aphis rumicis L. 3 Hyadaphis xrylostei (Schrank). 
2 Aphis medicaginis Koch. 4 Anuraphis crataegifoliae (Fitch). 
