ao 
ately to the higher concentration. In actual practice this condition 
may result from the drift of gas from nearby fumigation tents or by a 
slow Giffusion cf gas within a tent. In the experiments conducted 
the preliminary treatment wes varied with respect to the cyanide dos- 
age and the duration of exposure. following these preliminary treat— 
ments the scales in all experiments were given a standard fumigation 
treatment. Tne results appeared to confirm the observations of previ-_. 
ous workers. Protective stupefaction was induced by low concentrations 
of cyanide in both the resistant and nonresistant stages of the red 
scale. An interesting and somewhat surprising conclusion is that the 
percentage of scales surviving the treatment was inversely proportional 
to the concentration of cyanide used in the preliminary experiment. 
In other words, the lower the concentration of cyanide used in the pre- 
liminary treatuent, the more completely the scales were protected from — 
the later higher concentration. Exposure to the air for periods as 
long as $2 minutes following the preliminary exposure to sublethal 
doses failed to counteract the prutective effect of the preliminary 
treatment. 
Bureau laboratory at Experiment, Ga., taken over by Georgia Ex- 
periment Station.---Because cf curtailment in funds, it has been found 
necessary to discontinue the pecan insect investigations formerly ceon- 
ducted at Experiment, Ga.- This work was conducted in cooperation with 
the Georgia Experinent Station, which furnished the necessary quarters 
and facilities. With the withdrawal of Federal funds, the work has 
been taken over by the Georgia Experiment Station, which is financing 
the whole project, with the exception of a nominal allotment of Bureau’ 
funds for certain minor expenses. T. L. Bissell is being continued on 
the work under the new arrangement and is now a Collaborator of the 
Bureau of Entomolopy. : 
JAPANESE AND ASIATIC BEETLES : : 
Effects of sunmer drought on Jap beetle abundance.--H. Fox re- | 
ports that in a stucy cf the changes in populations of Popillia japon- 
ica Newm., as followed from year to year in three of the small parks 
or "squares" in the central business section of Philadelphia, it was 
found that the fluctuations observed were clearly correlated with the 
rainfall of the preceding summer. A similar correlation was also 
found in the case of numerous other localities situated near Phila-~- 
delphia. During the few years:in which the povulations in that city 
were growing largely by accessions from outside sources, no’ clear CGor- . 
relation between rainfall and populéticn was evident, but once the — © 
population reached a stage at which it was numerically equivalent to 
populations outside the city limits, subsequent change was clearly | 
connected with summer rainfall. The pertinent evidence on’ this point, S 
as regards the snall | 
tak 
s¥ ca her a 
in the following 
