248 Report OF THE DEPARTMENT OF ENTOMOLOGY OF THE 
requires but two years to develop; and as there are two broods 
the adults appear every year. This species is larger and the 
body is more wedge-shaped than the other. Its black and green 
color and the powdered appearance on the under side of the body 
also easily distinguish it from the smaller species. The song is 
a high sharp trill, most commonly heard about mid-day. Plate 
XXII, Fig. 4, shows a dog-day cicada with its wings spread. 
II. THE PALMER WORM. 
During the spring of 1900 many of the apple orchards of 
western New York became overrun with a small, active cater- 
pillar popularly known as the palmer worm and scientifically as 
Ypsolopus pometellus Harr. It was most abundant in Erie, 
Niagara, Orleans, Genesee, Monroe, Ontario, Wayne and Cayuga 
counties. The history of the insect shows that it has appeared in 
large numbers only after long periods of years, and that it usu- 
ally disappears as suddenly as it comes. We were, therefore, 
much interested to know whether the insect would be true to its 
record and disappear this time as quickly as it came. Accord- 
ingly, we took pains to ascertain whether it had again appeared 
in numbers during the past season but were unable to locate an 
orchard in which it was abundant. As was to be expected, how- 
ever, an occasional one could be found, and rarely a tree would 
contain quite a large number, showing that some agency or 
agencies, probably climatic, had prevented the development of a 
large percentage. Whether it will remain reduced in numbers 
for another long period of years remains to be seen. 
Food plants and nature of injury.— It is probable that this 
species has a large variety of food plants. Fitch,” recording an 
outbreak in 18538, considered the oak and the apple the most 
seriously injured, but adds that “all other trees and shrubs were 
more or less infested with the worms at this time.” Of the fruit 
trees the apple is evidently preferred although the caterpillars 
are known to feed upon the plum and cheery.” The writer has 
observed them in a few instances feeding upon the pear. 

16Noxious Insects of New York, p. 224. 
7Harris, T. W. As quoted by Slingerland in Cornell Univ. Agr. Exp. Sta. Bul. 187, p. 89. 
