6 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Table IV. — Summary of Table III; band-record experiments at Douglas, Mich., 1909. 



Observations. 



Total. 



Per 

 cent. 



Observations. 



Total. 



Per 



cent. 



Larvae and pupae collected from 



1,475 



194 



821 



1,015 



97 



100.0 



13.2 

 55.7 

 68.8 

 6.6 



Injured and winter-killed larva? . . . 

 Larva? of the first brood 



363 

 636 



194 



425 

 839 



24.6 

 43.1 



Moths emerging:- 

 1909 



Transforming larvae of the first 



33.2 



1910.. 



Wintering larvae of the first 





1909-1910 



66 8 





Larvae of the second brood 



56.9 







In numbers the second brood of larvae surpassed the first quite 

 materially. From October 18 to 25 no larvae were obtained, due to 

 prevailing cold weather. However, during the exceptionally warm 

 November quite a number were collected which under average sea- 

 sons would have remained undeveloped. Of the first-brood larvae 

 43 per cent transformed the same season, while 57 per cent wintered 

 together with those of the second brood. Of the total number of 

 larvae, 6.58 per cent proved to be parasitized by a hymenopterous 

 fly (Ascogaster carpocapsse Vier.). The proportion winter-killed and 

 injured by other causes was 24.6 per cent. 



SEASONAL-HISTORY STUDIES OF 1910. 



The rearing material in the spring of 1910 consisted of an abun- 

 dance of wintering larvae, which had been collected from banded 

 trees during the previous season. During the winter and throughout 

 the progress of the rearing experiments the insects were kept in cages 

 in an outdoor shelter (see Plate II), and were thus exposed to the 

 normal temperature conditions. 



WINTERING LARV^J. 



The wintering larvae invariably consist of individuals of the two 

 broods, as only a portion of the first brood transforms the same season 

 to form the second generation of moths, while the other portion win- 

 ters like all of the second-brood larvae. 



In the orchards a great number of the wintering larvae find protec- 

 tion for their cocoons under the rough bark of the trees and in cracks 

 and crevices in older trees, and many are frequently found imbedded 

 in decayed wood. It is mainly in the latter places that the codling 

 moth larvae find an escape from woodpeckers and other birds which 

 make persistent searches for the larvae during the winter. 



The cocoon of the wintering larva. — The winter cocoon of the larva 

 is proportionately small and completely sealed, and consists of heavy 

 walls for winter protection. In appearance these cocoons vary con- 

 siderably, depending largely upon the place selected by the larvae. 

 Under loose bark, where the larvae are not limited in space, the co- 

 coons are more or less oval, as shown in Plate I, figure 3. A slight 



