ORCHARD INSECTS 319 



be killed by contact insecticides. Whale-oil, or other soaps, 

 1 pound to 2 gallons of water, or kerosene emulsion con- 

 taining 10 per cent kerosene, are effective. Hellebore, 1 part 

 to 5 parts of air-slaked lime, may be used as a dust or as a 

 spray 1 pound to 50 gallons of water. In gardens where 

 water under pressure is available, the slugs may be washed 

 off by a strong jet from a hose, as they are frequently washed 

 off by heavy rains and are much less injurious in wet 

 seasons. 



162. The Codling Moth.* The common apple worm (1) 

 is well-known almost everywhere apples are grown and is 

 the most serious insect enemy of our most valuable fruit. 

 Where spraying is not practiced it often destroys 25 to 50 

 per cent of the crop and in 1907 Prof. A. L. Quaintance esti- 

 mated the total loss due to this insect in the United States at 

 $12,000,000. 



The adult moths are rarely seen as they fly at dusk and 

 closely resemble the bark of the apple on which they rest 

 during the day. They are small grayish moths with a wing 

 expanse of about three-fourths of an inch. The wings are 

 crossed with numerous fine lines of gray and brown, and 

 bear a large bronze-brown spot near the tip. 



When the larvae leave the apples in the fall they burrow 

 into corky crevices of the bark and there spin their white 

 silken cocoons in which they hibernate over winter. In this 

 stage large numbers of them are destroyed by woodpeckers. 

 About the time apples blossom the larvae transform to 

 small brown pupae, from which the moths emerge in two or 

 three weeks. The females then lay their eggs largely on the 

 leaves. The eggs are difficult to see, being about the size of 

 a pin-head, and look like small white blisters on the leaves. 



* Cydia pomonella Linn. Family Grapholithidce, super-family 

 Tortricina, see page 76. 



