THH MOXTJir.V lULI.KTFX. 



U>' 



iiiolli l.irvji spins its cocoon mostly iiiidci" 1 lie scales of hfii'k, in crevices 

 in tlic ti-cc ;in(l crjicks iiiid liolcs in llir *;i'o\in(l. Any cocoon wliicli 

 ocelli's in ;i crevice more IIimii one iiieli deej) iind of fi, width loo snudi 

 to permit llie pnrasite to eiitt'r, or under ;i ^ood sized scale of hark, 

 would he inaccessihle to the parasite, and as the worm is prone to crawl 

 for some distance into a crevice, sometimes to a distance of ten or 

 twelve inches. ])efore spinning, it is prohahle that for this reason a large 

 majority succeeds in eluding the parasite l)y crawling instinctively out 

 of reach. Without douht this inaccessihility of the apple worm is the 

 most important factor working toward the inefficiency of Callicpliiallcs. 

 Second — Along this same line, and working directly with llu' ahove, 

 is the interrelation of l)irds and the cotUing moth. 'J'his affects tli<! 

 parasite in two ways. The insect is a large and conspicuous oiut, slow 



Fig. .57. — CalUephialtes sp., draw- 

 ing of female. (Original.) 



moving and without means of defense. Undouhtedly a very great 

 number are destroyed by birds. Birds, however, have frequently 

 proven to be very efficient enemies of the apple worm, and in this w^ay 

 would destroy many immature CaUicphialtes within the codling moth 

 cocoon. An even more; important effect of birds upon the problem, 

 however, is their destruction of the apple worms even before they have 

 been parasitized. Those worms which are the least protected and which 

 are most accessible to Callifphilaks are the very ones which the birds 

 would first devour. It has been determined by the agents of the United 

 States Department of Agriculture that from 66 to 85 per cent of the 

 larvae of the codling moth are destroyed by birds. These figures would 

 prol)ably mean that most of the worms which could possibly be reached* 

 l)y the parasite are destroyed by other means either before or after 

 parasitism. The fact that the adult CaUicphialtes is unal)le to begin 



