FOOD PLANTS OF THE GIPSY MOTH IN AMERICA. 7th 
BAY-LEAVED WILLOW (Saliz pentandra L.). 
From trays started with first-stage larve only fourth-stage larve were pro- 
duced before they all died. No adults were obtained until fifth-stage larve were 
started. The foliage was rather distasteful to them and growth was slow. 
No field observations were made on this species. 
SANDBAR WILLOW (Salix interior Rowlee). 
Not as favored as the first two species, but more favored than the bay-leaved 
willow. Trays started with third-stage larve produced both male and female 
moths. 
No field observations were made on this willow. 
WITCH-HAZEL (Hamamelis virginiana L.). 
From the field came reports of the feeding of gipsy-moth larve in all stages 
upon this foliage, but probably more freely in the first stages. 
In the trays, adults were reared from first-stage larve, which fed steadily in 
all stages. 
The results given indicate in a general way the susceptibility of 
the species concerned to gipsy-moth attack. 
There is in some cases, at least, considerable variation in suscepti- 
bility of different trees of the same species. 
During the summer of 1912 foliage from two willow trees (Salix 
alba L.) were tested in trays at Melrose Highlands. They were 
growing side by side on lowland near a brook and both were in vigor- 
ous condition. First-stage gipsy-moth larve were placed in trays 
on the foliage of each tree. 
Those supplied with the foliage of one tree fed normally, grew 
rapidly, and in due time developed into large adults. The other lot 
grew very slowly and the larve were very small and small adults 
developed. Nearly three times as many eggs were secured from the. 
first lot as from the second. All the larve used in the experiment 
hatched from the same egg cluster. 
In 1913 foliage from the same trees and larve hatched from the 
egos of the previous year were used and the results were exactly 
reversed. 
This indicates that there is variation in results with the same spe- 
cies of tree, but in this case it was not constant. A number of experi- 
ments along this line are contemplated. 
COMBINATION-TRAY EXPERIMENTS. 
Several series have been conducted to determine feeding prefer- 
ences of gipsy-moth larvee when two species of foliage were supplied 
in the same tray. In deciding the combination of species to be used 
it was thought best to place in the trays species that are usually found 
growing together in the field. 
