20 
served shortness of the larval life, and upon the fact that the earliest 
larvee mature before the end of May, and upon the additional fact that 
we know that newly developed beetles are found early in June. Prof. 
John B. Smith, in a paper read before the Entomological Club of the 
American Association for the Advancement of Science, in August of 
this year, made the statement that there is but one annual generation 
in New Jersey. Theadult beetles develop from the larvae which have fed 
during the summer, entering winter quarters as early at the first week 
in August. This state of affairs may probably hold in more northern 
regions, but in Washington it is safe to say that there are two genera- 
tions, because, as just stated, newly developed beetles (the progeny of 
those which hibernate) appear in early June. These lay eggs, and, in 
fact, egg-laying may continue until the end of September, and larvee 
have actually been found by Mr. Pergande in October. 
REMEDIES. 
The spraying with arsenical poisons recommended in this bulletin has 
been generally adopted, and with universal success where proper pre- 
cautions have been observed and where sufficient care has been taken. 
The most careful record of experiments that has been published was re- 
corded by Prof. Smith in Garden and Forest for June 19,1889. Prof. 
Smith’s experience was interesting, not only because he treated some 
very large trees upon the Rutgers College campus, but from the fact 
that he has introduced a variation in the way of adding a small quantity 
of kerosene emulsion to the arsenical mixture for the purpose of making 
it spread over the leaves to wet them thoroughly. The dense veivety 
pubescence characteristic of the under side of certain elm leaves causes 
them to shed water readily, and this difficulty is overcome by the addi- 
tion of the oil. The formula which he recommends is water, 100 gal- 
lons; London purple, 1 pound; standard kerosene emulsion, 1 gallon. 
This mixture he has found does not injure the foliage at New Bruns- 
wick. It is, however, stronger than is necessary, and the same amount 
of London purple and kerosene emulsion may be added to 150 or even 
200 gallons of water with almost equal efficacy and with much greater 
safety. The difficulty of reaching the tops of tall trees was overcome 
by Prof. Smith in the folowing way: He used a hose 50 feet in length, 
tothe end of which was attached a proper nozzle. The upper 10 feet 
were fastened to a bamboo pole of this length. With this he was able 
to throw a spray upon all branches 20 feet and over from the ground. 
temoving the spraying nozzle a solid jet could be thrown among the 
higher branches. This solid jet, he found, broke into quite a fine spray 
about 25 feet from the ground, and wetted the branches thoroughly to 
a height of 30 feet. A light ladder 20 feet in length gave him access to 
the center ofthe largest trees, whence the extreme tops could be reached. 
For the largest trees he used about 20 gallons of the mixture just men- 
tioned. He was successful in destroying all the beetles and larve, and 
most of the eggs. 
