MONTELY LETTER OF THE BUREAU OF ENTOMOLOGY) 9 g, Deqartment of 
UNITED STATES DEPARTMENT OF AGRICULTURE 
Number 236 (Not for publication) January 1934 
FRUIT INSECTS 
West indian fruit fly work transferred to Puerto Rico.--Inten- 
Sive inspections in Key West have failed to disclose field infesta- 
tions of either of the West Indian fruit flies, Anastrepha acidusa 
Walx. and A. suspensa Loew, since early in the fall and indicate that 
the eradication campaign being carried on by the State Plant Board of 
Florida will be successful. In keeping with this effort to eradicate 
the fruit flies, ali individuals that had been used in experiments 
were killed early in November 1933. The station at Key West, main- 
tained in cooperation with the Florida State Plant Board since Novem- 
ber 1932, was discontinued in December 1933. There is a definite need 
for more information on the habits of these fruit flies and the effect 
various poisons: have on them. L. C. McAlister, Jr., has been trans- 
ferred to Puerto Rico where, through the cooperation of the Office of 
Experiment Stations, he will be furnished quarters at Mayaguez. He 
will continue to carry on studies to test the effectiveness of vari- 
ous poison sprays, attractants, etc. 
Tartar emetic has little effect on the maturity or quality of 
citrus fruits.--W. W. Yothers, in charge of the laboratory at Orlando, 
Fla., in cooperation with other bureaus of the Department, has been 
studying the effect of tartar emetic on the time of maturity and the 
composition of citrus fruits. Tartar emetic is an effective poison in 
fruit-fly baits and if it does not injure fruit may be one of the 
Sprays that can be used on citrus. Analyses just completed show that 
the presence of tartar emetic has no cffect on the maturing of the 
fruit. 
"Protective stupefaction" caused by light dosage of hydrocyanic- 
acid gas.--F. H. Lathrop, in charge of the Whittier, Calif., labora- 
tory, has just conducted a number of experiments, in cooperation with 
H. L. Cupples, of the Bureau of Chemistry and Soils, to determine the 
importance of "protective stupefaction" in fumigation operations. In 
recent years a number of workers have found that if the California 
red scale (Chrysomphalus aurantii Mask.) and several other species of 
scale -insects are first exposed to a sublethal concentration of cya- 
nide gas and then exposed to the normal lethal dosage the percentage 
vf kill is distinctly less than when the scales are exposed immedi- 
