New York AGRICULTURAL EXPERIMENT STATION. 448 
ing characteristic galleries. Pupation takes place under the bark, 
the adults finally gnawing their way out. There are probably 
several broods in one season. It attacks a variety of fruit trees. 
T'reatment.— As a preventive measure trees should be kept in 
a healthy, vigorous condition; as such trees are less liable to attack 
than weak ones. Trees which become badly infested should be 
dug up and burned. 
PEAR DISEASES. 
FIRE BLIGHT. 
(Bacillus amylovorus (Burr.) De Toni.) 
Description, etc.— This disease shows itself in the dying of en- 
tire twigs, large branches or even the tree itself. It is a bacterial 
disease that has long been known but whose real nature was first 
discovered in 1879 by Dr. Burrill of Illinois. It was afterwards 
studied very carefully at this Station by Dr. Arthur®* and more — 
recently by Mr. M. B. Waite * of the United States Department of 
Agriculture. 
The disease usually makes its first appearance soon after the 
blooming period. The young fruit clusters and the twigs bear- 
ing them turn black. The leaves also blacken and die but do 
not fall. If affected twigs are not removed the disease rapidly 
works its way down into the larger branches. 
According to Waite*® the blight germs do not live over winter 
in the soil. Moreover, he finds that in the majority of the affected 
branches even, the germs die soon after the close of the growing 
season. It is only in a small proportion of the affected branches 
that the germs survive the winter. Such “hold over” cases, as 
he calls them, become centers of infection during the following 
spring. Branches in which the germ is alive do not show » 
definite line of demarcation between the healthy and diseased 
36 See Annual Reports of this Station, 1884: 357; 1885: 241; 1886: 275. 
37 Waite, M. B. The Cause and Prevention of Pear Blight. Year-Book U. 
S. Dept. Agr., 1895: 295-300. 
38 Loc. cit. 
