Jf MONTHLY LETTER OF THE BUREAU OF ENTOMOLO 
42 UNITED STATES DEPARTMENT OF AGRICULTU 






STORED—PRODUCT INSECT INVESTIGATIONS 
E. A. Back, in Charge 
Dr. R. T. Cotton returned to Washington on March 29 from a trip to 
Manhattan, Kans., where he conferred with Gilbert A. Schenk regarding the 
bureau's work on flour—mill insects. While there he visited the ento— 
mological department of the Kansas State Agricultural College, and gave 
an informal talk before the Popenoe Club on some new developments in fu- 
migation. 
On Dr. Cotton's return trip he made stops at St. Joseph, Kansas 
City, and St. Louis. At St. Joseph a series of experiments were carried 
on at a large candy factory, to determine the dosage required for the 
successful fumigation of nut meats with ethylene oxide and HCN. The 
experiments were made in a vacuum tank of 300 cubic feet capacity. In 
Kansas City a number of visits were made to firms and agencies interest-— 
ed in the problem of flour-mill insects. Dr. Cotton called on vari- 
ous firms in the nut-meat and food-—product business in St. Louis to 
discuss methods of fumigation for the control of losses by insects. 
In checking over the infestation records secured from bean ware— 
houses, A. QO. Larson found an isolated. case of heavy infestation by 
bean weevils and determined to locate the source, if possible. When 
the grower of the infested beans was found he said that his 1928 bean 
crop had been the first grown on his place, that he had no bean straw 
Or beans on the premises, and that he was sure that his neighbors had 
none. As no beans had been grown within about two miles of this grow- 
er's infested field, Mr. Larson's experience led him to believe that 
persistence would uncover the source of infestation. On learning the 
experiences of other growers, this farmer was led to recollect that 
after he had done the planting he had placed about two pounds of left— 
over beans in an open pail, which he hung from the rafter of a shed 
near the field where his beans had been grown. An examination of the 
seeds showed them to be badly infested by bean weevils, thus estab-— 
lishing another definite case of the origin of field infestations. 
Early in March W. D. Reed attended a committee meeting of the 
Fresno Federal Business Association, to consider arrangements for the 
joint meeting of the Federal Business Association of California, which 
is to be held in Fresno April 6. 
i On March 20 Perez Simmons and W. D. Reed attended a meeting, held 
in Fresno, of the State Fig Clean-Up Committee. 
Perez Simmons spent March 13 and 14 at the University of Califor- 
nia, doing library work. 
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