August, ’23] DUDLEY & SEARLES: MARKING CUCUMBER BEETLES 
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and these were in accord with the best information. The trouble lay in 
their enforcement, and the fact that the subject of one official order was 
the epidemic nature of the dysentery and warning against flies indicates 
that the regulations were poorly enforced throughout the whole region of 
southwest France. 
We must not assume too readily that as commissioned entomologists 
overseas we would have remedied all this. Early in 1918, when there 
were few flies, other things seemed more important. Fly control means 
work, and at that time the great need of the engineer troops in the rear 
was man power. The forest troops were working in shifts, 24 hours a 
day, racing with one another to meet the insistent demands for more 
lumber and ties, and it was no simple matter to get company commanders 
to give much attention to sanitary improvements. 
But the writer feels that with commissioned entomologists assigned 
to groups of camps much that was unfortunate would not have de¬ 
veloped. Energetic and insistent men could have accomplished a great 
deal with relatively little work, done at the right time , and such service 
would have paid dividends, both in money and in the increased comfort, 
efficiency and safety of the soldiers. 
COLOR MARKING OF THE STRIPED CUCUMBER BEETLE 
(.DIABROTICA VITTATA FAB.) AND PRELIMINARY 
EXPERIMENTS TO DETERMINE ITS FLIGHT 
By John E. Dudley, Jr., and Ed. M. Searles 
Bureau of Entomology , U. S. Department of Agriculture. 
Abstract 
The wide spread depredations of the striped cucumber beetle, including both its 
feeding injuries and its role in the transmission of bacterial wilt and mosaic of the 
cucurbits, have been estimated to damage the crop to the extent of 13,000,000 to 
15,000,000 a year in the United States. Many of the recognized control measures in 
the past have been of little or no value in killing the beetle, and their virtue as repel¬ 
lents has depended upon repeated applications to the growing crop's because the 
beetles are constantly flying from field to field. 
This project was undertaken to find the limits of the powers of flight of the beetle 
and its general habits as to flight. 
After experiments with various dyes and coloring substances covering a period of 
three years, the most successful material for marking has been found to be six parts, 
by volume, of denatured alcohol (denatured with methyl alcohol), four parts of 
commercial, cut shellac, the mixture colored with a saturated solution of various 
anline dyes in alcohol. This material may be sprayed on the beetles with an atom¬ 
izer. It dries quickly; adheres well to the body of the insect; retains its color in¬ 
definitely; and does not appear to interfere in anyway with the normal functions of 
the insect. 
During the summer of 1922 three lots of beetles totaling 25,786 individuals, were 
marked and released. Of these, 49 were recovered after an average interval of 4J4 
days. They flew an average distance of one-half mile, five flying over a mile each. 
This project is to be continued during the season of 1923. 
