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The habits of young grasshoppers to seek the soil crevices during a 
rain results in the burial of millions beyond the possibility of a resur- 
rection. This, with the development and propagation of fungous 
diseases among the nymphs, are the most potent natural agencies 
which destroy grasshoppers during wet summers. 
The fact that the differential locust will deposit eggs in logs has 
given some support to the idea that crevasse water introduces the 
grasshoppers. There are sections of the delta, however, which are 
almost annually overflowed by the high water of the Mississippi and 
its bayous and which would be common infesting grounds were this 
the case, but these do not seem to suffer except when dry summers 
prevail. 
SOME INSECTICIDE EXPERIMENTS. 
By C. L. Maruarr. 
A series of experiments with certain insecticide substances was made 
in the spring and early summer of 1900 and are herewith recorded. 
The experiments were especially designed to test the effect of various 
substances which might be used against the San Jose scale, both as to 
their effect on trees and efficiency as destroyers of the scale. They 
included work with (1) crude petroleum; (2) refined kerosene; (3) lime, 
sulphur, and salt wash; (4) hot water; (5) Bordeaux wash and kerosene 
emulsion; and (6) a kerosene and lime emulsion. The experiments 
with the latter two substances were made at the suggestion and with 
mixtures furnished by Professor Galloway. An experiment was also 
made, at the suggestion of Dr. L. O. Howard, with a heavy lime wash 
or whitewash. For the washes containing lime the period immedi- 
ately following the applications was unusually favorable, little rain 
falling for upwards of two or three weeks. In the use of crude 
petroleum and kerosene nothing especially new is to be noted except 
the fact that the treated trees were not in any way injured and the 
effect on the scale was all that could be desired. The lime and salt 
wash, rather unexpectedly for the East, proved to be a very efficient 
insecticide, doubtless owing to the fact, however, that the weather 
conditions were exceptionally favorable. The lime emulsion indicated 
good results. The Bordeaux and oil mixture was less favorable, and 
the whitewash spray, while most promising in appearance at the out- 
set, was valueless as to results in the outcome. 
Crude and refined petroleum.—A series of plum, apple, and pear 
trees were sprayed March 22 with crude petroleum (43° Baumé), the 
applications being made thoroughly enough to completely wet the bark. 
The plum trees were thickly infested with Diéaspis pentagona and the 
pear trees with the San Jose scale. Some of these trees had been 
pruned back heavily, and others were straggling trees 10 or 12 feet in 
4670—No. 30—01——3 
