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G> MONTHLY LETTER OF THE BUREAU OF_EN* OLOGY 
¥ UNITED STATES DEPARTMENT OF AGRICULTI 

Number 126 | ~ “Sa * f October, 1924 

CEREAL AND FORAGE INSECT INVESTIGATIONS 
G? A. Dean, Senior Entomologist, in Charge 
F. W. Poos, in charge of the European corn borer laboratory at Sandusky, 
Ohio, has been granted leave of: absence for 44 months, beginning with October, 
to pursue graduate work at Ohio State University. During his absence L. H. 
Patch will be in charge of the laboratory. 
W. R. Walton returned October 4 from a several day’s inspection trip of 
the European corn borer work conducted by the Arlington laboratory. He finds 
that there has been not only a very marked decrease in the intensity of 
infestation in the Massachusetts area, but also very little spread in the 
infestation. The decrease apparently is due principally to the adverse climatic 
conditions which prevailed during the summer of 19235. The thorough clean-up 
of the fields, gardens, and small weed areas and the fall plowing of practically 
90 per cent of the cultivated fields probably also contributed considerably 
to the decrease in the infestation. 
LL. H. Worthley, E. G. Brewer, and George A. Dean spent several days in 
the early part of October inspecting the European corn borer infestations in 
Ohio, Michigan, and Ontario. During the two days inspection trip in Ontario 
they were accompanied by Arthur Gibson, H, G. Crawford, L. 68, McLaine, and 
Prof. Lawsen Caesar. An important corn borer conference was held at London, 
Ontario, October 10. In addition to the entomologists, the conference was 
attended by the Dominion Minister of Agriculture, the Ontario Commissioner 
of Agriculture, and the Agricultural Agents of Ontario. In many parts of Kent 
and Essex Counties, Ontario, where corn is the principal crop, the corn borer 
has increased from less than 1 per cent stalk infestation of last year approx- 
imately to 85 per cent stalk infestation this year, and from no commercial 
damage of a year ago to as high as 25 per cent commercial injury in some fields 
of dent corn. The spread of the infestation in Michigan has increased fully 
300 per cent. In addition to an increase of 150 per cent in the spread of the 
infestation in Ohio there also has been a marked increase in intensity of the 
infestation. The spread of the infestation in Pennsylvania also has increased 
about 150 per cent. Messrge. Worthley, Dean and Brewer also attended a corn. 
borer conference held at Columbus, Ohio, October ll. 
Mr. Caffrey, of the Arlington, Mass., laboratory, reports that in add- 
ition to the recoveries of the Fveristes roborator Fabr. parasite of thecorn borer 
the recovery of three pupae of the Microgaster tibialis Nees parasite has beer made. 
