85 



The Codling Moth. 



This is one of the most important pests of the apple in this 

 country. The writer has been accustomed to spray his trees 

 for this pest in the approved way, and in 1919 a count of the 

 apples gathered from- one tree, which had been sprayed regu- 

 larly for several years, showed that only about 10 per cent of 

 the fruit was wormy. In 1920 this tree was not sprayed, and 

 a similar examination of the fruit gathered showed over 90 per 

 cent wormy. The average cost of spraying an apple tree, 

 even when the work is hired, is less than $2, so that it pays 

 well to spray, as has been repeatedly shown for large orchards 

 as well as in the case of the single tree referred to. 



The codling moth caterpillar winters near the apple tree and 

 nearly always under some loose piece of bark on the trunk or 

 one of the limbs. In the spring it changes to a small dark- 

 colored moth which flies at night, is not attracted to lights, 

 and is therefore seldom seen. It comes out a week or two 

 after the apple blossoms fall, and lays its eggs singly, here and 

 there, on the young leaves, twigs and on the fruit which 

 is now beginning to form. 

 About a week later the eggs 

 hatch, and the tiny cater- 

 pillars feed a little on the 

 leaves but soon crawl to the 

 fruit, where from sixty to 

 eighty of every hundred go 

 to the blossom end and bore 

 inward to the core. The 

 others appear to bore in 

 through the side of the fruit. 



Around the core the cater- 

 pillars now feed for about a 

 month until full grown. 

 They then bore out, gener- 

 ally through the side of the 

 fruit, and crawl down the tree until they find pieces of loose bark 

 where they can go. Each now, under a piece of bark, gnaws 

 out a little oval cavity which it lines with silk, and in this the 

 caterpillar changes over into the moth. 



Codling motli: a, work of caterpillar; S 

 b, point of entrance: dy pupa; e, full- 

 grown caterpillar; /, g, moth; A, head 

 of caterpillar; i, cocoon. 



