494 



Journal of Agricultural Research voi. xviir, No. 9 



Table II. — Number of parasites issuing and dates of emergence from adults of Calosoma 

 sycophanta, jgij, 1916, and igij 



The late issuance of flies as recorded in 191 5 was undoubtedly the 

 result of the issuance of a partial second generation at a time when it 

 was improbable that suitable hosts could be found active in the field. 

 According to the record secured in the breeding experiment in 191 8, 

 and cited above, it would seem that the activity of the progeny of the 

 summer generation of parasites is entirely dependent upon the activity 

 of the host. That is, if beetles parasitized by flies of the summer genera- 

 tion immediately become inactive and seek dormancy, the larvae of the 



