14 INSECT AND FUNGOUS ENEMIES OF THE APPLE. 
Complete observations of the life cycle have also been made on a 
total of 597 individuals from many parts of the country, which give 
a final average per individual of 50.71 days, differing only a fraction 
of a day from the time determined in an essentially different manner. 
Approximately 50 days would therefore appear to be the average 
life-cycle period for the plum curculio for the country as a whole. 
The variation for different individuals will be considerable, and as 
actually determined in the case of individual records was from 37 
to 58.45 days. 
For practical purposes there is only one generation of the beetles 
each year. The adults, developing from fruit during the summer, 
spend the remainder of the time, until hibernation begins, feeding 
upon the foliage and fruit. With the approach of cold weather the 
beetles seek shelter, apparently wherever they may be, under trash in 
orchards, along fences, and in similar places. They are always abun- 
dant in woods adjacent to orchards. 
CAN THE CURCULIO BE CONTROLLED BY SPRAYS? 
During the past few years much experimental work has been done 
in the use of arsenical sprays in the control of the curculio on apple, 
notably by Prof. Stedman in Missouri and Prof. Crandall in Illinois. 
Prof. Crandall’s investigations extended over two years. In regard 
to the value of the work he states as follows: 
To sum up the matter of spraying for the curculio from the standpoint of 
results obtained during the two seasons of 1903 and 1904, it seems possible, 
under favorable conditions and with a reasonable number of applications, to 
control curculios to the extent of from 20 to 40 per cent of the possible injury. 
There is benefit to be derived from spraying, but not that degree of benefit 
which would warrant commendation of spraying as the one great panacea of 
injury done by the curculio. 
Many experiments by the Bureau of Entomology emphasize in 
general the soundness of the conclusions of Prof. Crandall. In the 
following table are given results of spraying for the curculio on 
apple as carried out by the Bureau of Entomology in different parts 
of the country. 
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