376 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
45 dead and 4 alive. On the third morning all were dead. From this 
we can judge that the glycerin does not interfere with the poisonous 
properties of sodium fluoride. 
EMERGENCE RECORDS OF THE PEACH TREE BORER, AEGER- 
IA EXITIOSA (SAY), IN PENNSYLVANIA 
By Eugene M. Craighead, Bureau of Plant Industry, Harrisburg, Pa. 
Successful control of the peach tree borer by the use of Paradichloro- 
benzene (commonly called PDB) is dependent on an accurate knowledge 
of its habits and especially on the determination of methods for securing 
the maximum kill. In order to secure accurate data on adult emergence, 
experiments were conducted for two years in Franklin County, Pa., at 
the Chambersburg Laboratory of this Bureau under the supervision of 
Prof. J. G. Senders, Director. 
In 1921 from May 15th to August 10th, nearly 700 cocoons were col¬ 
lected, of which number about 500 contained larvae. From the 500 
pupae, 174 males and 184 females emerged, making a total of 358 adults. 
About 4% of the pupae were parasitized. In May, 1922, wire cages 
