14: FRUIT INSECTS 



days, while the eggs of the later generations, because of the 

 higher temperature, require a much shorter period, 5 or 6 days. 

 The time at which the first brood eggs hatch and the young 

 larvae enter the fruit is of great importance from the standpoint 

 of control, and has been given careful attention by entomologists. 

 In spite of many disturbing factors it may be said that in general 

 the majority of the eggs hatch about 3 or 4 weeks after the 

 petals fall. The newly hatched larvae (Fig. 10) are less than -^ 

 inch in length and are of a semitransparent whitish color, with 

 a shiny black head and blackish thoracic and anal shields. At 

 first they may feed slightly on the foliage, but usually they 

 crawl directly to the fruit, which they enter in the majority 

 ^^^^ of cases at the blossom end. 



' ^^^^^^^1^1 ^ f^w enter at the stem end 

 ;JB^^M and a considerable number 

 JSm^^^K^ commence their burrows 

 ^^^^^^^^ where a leaf or another apple 



^^Jjj^^^^^ touches the surface of the 



^^j^JK^^r^ fruit. In the case of later 



^^m^^^^^ generations a much greater 



^^^^^^ proportion of the larvae en- 



FiG. 11. — Full-grown codiin-moth ter at the side, a fact of great 

 ^ ■ practical importance. After 



feeding slightly in the calyx cup the larva burrows directly to 

 the core, where it devours the seeds and eats out a considerable 

 cavity, leaving it partially filled with a filthy mass of excrement 

 loosely webbed together with silk (Fig. 12). Larvae of later 

 generations entering at the side frequently eat out a small bur- 

 row or cavity just beneath the skin before starting the burrow 

 towards the core. 



When nearly full grown the larva eats out a new burrow 

 directly to the surface but keeps the opening plugged with ex- 

 crement until it is ready to leave the fruit (Fig. 14). The time 

 spent in the fruit varies considerably, but averages not far from 



