34 Farmers’ Bulletin 1128. 
tennxe. The species is found in the spring in rather large colonies on 
the underside of the leaves, which it causes to curl and twist. 
THE HOUGHTON GOOSEBERRY APHIS.' 
A pale green species has become prominent in recent years by 
reason of its attacks on gooseberries. The wingless ones are green 
and covered with knobbed hairs. The winged ones are dark green 
with a brown head and thorax. The insects attack the growing 
Fig. 26.—The Houghton gooseberry aphis: a, Winged form; b, cornicle of winged form; c, antenna of 
winged form. a, Much enlarged; b, c, more enlarged. 
tips and ultimately produce a ‘‘witches broom” like that seen in 
the illustration (fig. 25). 
SEASONAL HISTORY. 
The eggs are laid on the bark under the loose folds which extend 
down the twigs. Occasionally also they occur on the bases of the 
buds or even on the thorns. 
The eggs hatch with the expanding buds and the young stem- 
mothers place themselves on the underside of the leaves, the petioles, 
or tender twigs. The leaves soon curl and twist, forming a protec- 
tion for the stem-mother and her young. The stem-mother and 
succeeding wingless forms therefore cause the twisting of the leaves. 
The winged forms (fig. 26) occur in all generations from the second 
onward, even the stem-mother producing some winged forms. 
1 Myzus houghtonensis (Troop). 
