INSECTS INFESTING THE APPLE TREE 



105 



in from seven to ten clays, and begins to eat eagerly and bur- 

 row toward the core. 



Fig. 81.— A, blos- 

 som end or calyx of 

 apple, and where lar- 

 va is supposed to en- 

 ter the fruit ; B repre- 

 sents an empty space 

 where carpellary ova- 

 rium or shell contain- 

 ing the seeds was lo- 

 cated before the en- 

 trance of the larva ; C 

 represents the bur- 

 row made by the 

 larva through the pe- 

 ricarp by which it 

 escapes from the fruit when it is ready to assume the pupa or 

 chrysalis form ; D, appearance of larva in burrow when six 

 days old ; E, appearance of larva in burrows Avhen ten days 

 old. 



The larva when hatched can scarcely be seen with the 

 unaided eye ; at six days it measures nearly one quarter of an 

 inch in length, is about as thick as a fine silk thread, and 

 shows first signs of excrement at burrows (D Fig. 81) ; at ten 

 days three eighths of an inch, and about as thick as a number 

 twenty wire (E Fig. 81). It has burrowed by this time about 

 three fourths of the distance to the core (B Fig. 81). At 

 twenty days nearly full grown (c. Fig. 79), and often as large 

 {e, Fig. 79). 



AVhen the larva is ready to assume the pupa or chrysalis 

 form, it leaves the fruit by gnawing a hole through the peri- 

 carp (C Fig. 81). Nature has supplied it with a spinneret, 

 the opening apparently in the lower lip, from which issues a 

 viscid fluid in a fine stream and hardens into silk on contact 

 with the air. By this means it lowers itself to the ground or 

 intervening branches. If it reaches the ground, it immedi- 

 ately crawls toward the tree, and on its journey can often be 



