1898 



The Cornell Reading-Courses 



Fig. 95. — Codling moth 

 greatly enlarged 



egg, 



If the weather is warm, egg laying begins in from three to five days 

 after the moths have emerged; but if the weather is cold, it may be deferred 



for some time. The average life of the moth 

 is about ten days, and each female lays from 

 thirty to over one himdred eggs. The glisten- 

 ing, flat, oval, scalelike eggs are about half 

 the size of a pinhead in diameter (Fig. 95). 

 Those of the spring generation are laid mostly 

 on the leaves, though a few are sometimes 

 placed on the frtiit and branches. Though the 

 eggs are deposited throughout a period of 

 several weeks, the greatest number are laid 

 about three weeks after the blossoms fall. The 

 eggs of the spring brood hatch in from six to 

 ten days. In general in New York, though the condition of the weather 

 will alter this somewhat, the earliest laid eggs will begin to hatch about 

 three weeks after the petals fall, and hatching will be at its height about a 

 week later, or about four weeks after the petals fall This point is impor- 

 tant from the standpoint of control and should be borne well in mind. 



The newly hatched caterpillars are about one-sixteenth inch in length 

 and semitransparent whitish in color with a blackish plate just behind the 

 head and another at the hinder end, which are known respectively as the 

 thoracic and anal shields. On the back are small blackish tubercles, 

 which become less distinct with age. These little larvse at first feed to a 

 slight extent on the leaves, but most of them make their way directly to 

 the young fruit where they begin feeding within the calyx lobes. Seventy 

 per cent or more of the caterpillars enter 

 the apples at the blossom end. It is this 

 fact that is taken advantage of in spraying 

 for the first brood of codling moth. After 

 feeding for a short time in the calyx cavity 

 (Fig. 96) the larva burrows to the core, 

 eats the seeds, and hollows out a large 

 cavity, which becomes filled with masses 

 of excrement loosely webbed together with 

 silk (Fig. 97). The length of time spent 

 in the apple by each larva varies con- 

 siderably, but averages about four weeks 

 for the first brood. The larva then bur- 

 rows to the surface and makes an exit 

 hole, usually on 'the side of the apple, which it keeps plugged with frass 

 (Fig. 98). When full grown the larva measures about three-fourths inch 



Fig. 96. — Young codling moth 

 larva feeding in calyx cavity 



