190 PLANT LICE. 
with the wingless females, after which the females deposit their 
eggs around the buds to pass the winter. 
“This in brief is the life cycle of this aphis. The migration 
was observed in the field and proven by artificial transfers. It 
was surmised from the mixed up description of Aphis rumicis, 
as the louse on Shepherd’s Purse and Pigweed is called, (also 
known by the common name of ‘Black Dolphin’ and ‘Bean 
Louse’), that Aphis euonymi, the one on euonymus or Waahoo. 
and Aphis viburni, the Snow Ball louse, might be related. Dr. 
Thomas and also Fitch quoting from Walker gives Aphis euonyms 
as a synonym of Aphis rumicis, but does not suggest that they 
migrate. During the spring of 1892 a louse was found in the 
flower clusters of snowball which resembled the descriptions of 
the Waahoo louse and Bean louse, and we partially concluded 
that-it must be the Snowball louse because Buckton states that 
Aphis viburni infests the flower clusters. With the intention of 
solving this riddle and determining the life-history of the Snow- 
ball louse as already stated, transfers of Aphis euonyni were 
made from the Waahoo to the Snowball May 17th, and covered 
with netting. At the same time search was made for Aphis 
rumicis on such weeds as Shepherd’s Purse, Pigweed, Curled 
Dock and Thistles, but none could be found, nor was any plant- 
louse found on these weeds, with the exception of a root form 
on Shepherd’s Purse, till June 2nd. In the meantime the Apiis 
euonynu transferred to the Snowball thrived and worked prin- 
cipally in the flower clusters; at the same time another species 
supposed to be the Snowball louse could be found working on 
no part except the leaves. 
“On May 23d and 25th winged specimens of the louse trans- 
ferred from Waahoo to Snowball were transferred to Shepherd’s 
Purse, Curled Dock and Bean; which had been plotted, covered 
and kept in the greenhouse for this purpose. The louse infesting 
leaves of Snowball was treated in the same way, but it refused 
to colonize on any of the plants named and died; while the 
Waahoo louse thrived and increased to such numbers on the 
Shepherd’s Purse as to kill the plant. It did not do so well on 
the Dock in confinement, and all perished on the bean. 
“Pupz of Aphis euonymi were found on Pigweed about the 
middle of September, taken into the laboratory and confined. 
