54 MAINE AGRICULTURAL EXPERIMENT STATION. I914. 



arzriisis ) in summer for it tallies with lactiiccc recorded from 

 Sonchiis in Germany: and from currant, gooseberr}-. lettuce 

 and sow thistle in England.* 



Like the species previously discussed, this aphid winters on 

 the currant in the egg stage, the spring generations feeding 

 upon the sap of the growing leaves. The collections T have 

 made from flowering currant have been mainly from the imder 

 surface of the leaves which their presence causes to curl and 

 cluster though not in such a dense mass as those infested by 

 Aphis varians. They are sometimes also found on the stem. 



During the last of June winged and wingless females, pupse 

 and nymphs can still be found upon the currant. The winged 

 females apparently take flight to lettuce, sow thistle, and pro- 

 bably to related plants, although I have not succeeded in mak- 

 ing the transfers live under control conditions. These have 

 shiny black heads ; black antenna with sensoria on III, TV and 

 A\ as shown in the figure; thoracic lobes black; ventral meso- 

 thoracic plate black; abdomen glabrous, light green with three 

 large lateral black spots and one smaller one cephalad the corni- 

 cle, the cornicles being on a fourth large black spot, a mass of 

 little black spots speckled near the cornicles and a median black 

 blotch not quite reaching the base of cornicles ; cornicles light 

 green with black tip: cauda light green. The pupae are uniform 

 pale green with paler appendages ; tips of cornicles and tarsi 

 dusky; a few deeper green lines on abdomen. 



\\'inged females of a later generation taken from sow thistle 

 (Sonchiis arvensis) about the first of August have the abdomen 

 light yellowish green to olive green and the black markings as 

 \v;th the currant generation. The wingless females taken at 

 the same time are entirely pale whitish or yellowish green and 

 immaculate, and the same description answers for the nymphs. 

 The pupge are also pale 3'ellowish green and immaculate like 

 the wingless female, though the edge of the wing-pad is slightly 

 dusky. The antennse are shown in the figures. 



In the fall winged females flv back to the currant. 



^1912. Theobald. The Journal of Economic BiologA', Vol. 7, pt. 3. 



