INSECTS 



199 



The pupa. After leaving the apple the larva seeks a favorable 

 place in which to spin its cocoon for pupation. Sometimes it 

 lowers itself directly to the ground by means of the silken thread 

 it can so prodigally spin, pupating in litter or some other protec- 

 tion found on the ground. Usually, however, it crawls down the 

 limbs of the tree to the trunk, hiding itself under partially loosened 

 bark or in crevices and cracks in the wood, and spinning about 

 itself an elongated, tightly woven cocoon. In this silken sleeping 

 shroud are undergone the subtle, invisible transformations from 

 larva to pupa and from 

 pupa to imago. 



The pupa itself is a 

 contracted embodiment of 

 the larva. The average 

 length is about half an 

 inch, and the color ranges 

 from light to dark brown. 



The length of pupation 

 varies greatly. The aver- 

 age time is from two weeks 

 to sixteen or eighteen 

 days. Eventually the pupa 

 works its way from the 

 cocoon as an adult moth, 

 and after a brief interval the female begins to deposit eggs for 

 another brood. The larvae entering cocoons in the fall do not at 

 once pupate, but hibernate as larvae, pupating at the approach of 

 warm weather the following spring. 



Treatment. It is evident that control of the codling moth must 

 be effected chiefly by measures prohibitive of the entrance of the 

 larvae into the fruit. The best means of securing this end is the 

 use of poison sprays. There are several arsenicals which have been 

 and are still being used, but from the point of view of efficiency, 

 economy, and harmlessness to foliage and fruit, arsenate of lead is 

 doubtless superior to all. Clean, smooth-barked trees and ground 

 free of rubbish also unquestionably help the orchardist by depriving 

 the worms of their pupating quarters, but these conditions are not 

 essential — only desirable. 



Fig. 85. Pupae of the codling moth.. (Depai 

 ment of Entomology, Cornell University) 



