34 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



tuck orchards, however, were all carefully handled, and the results 

 of these observations show approximately the normal proportion of 

 winter-killed larvae. 



SPRING BROOD OF PUP^. 



Time of pupation. — In the rearing cages pupation commenced on 

 May 9, reached a maximum May 19, and terminated June 26 (Table 

 XXXII). The relative rate of pupation is illustrated by a curve in 

 figure 12. It will here be observed that pupation occurred rather 

 irregularly and that the time when the larger number of individuals 

 pupated extended over a longer period than in 1910. This, of course, 

 had a direct bearing upon the time and rate of emergence of the 

 moths of the spring brood, which, . like the pupae, appeared very 

 irregularly. 



Table XXXIII. — Length of pupal stages of the spring brood, Douglas, Mich., 1911. 



