64 



FRUIT INSECTS 



A number of hymenopterous parasites attack this leaf-roller. 

 Toads often eat many of the caterpillars that drop from the 

 trees, and red- winged blackbirds are efficient enemies in Colo- 

 rado. 



Means of control. 



The leaf-roller has been found a difficult insect to control by 

 ordinary spraying with arsenical poisons. 

 Recent work in Colorado has shown, how- 

 ever, that over 95 per cent of the eggs can 

 be destroyed by one thorough application 



Fig. 67. 



Small apples eaten by the leaf-roller. 

 Knight photo. 



Fig. 68. — 

 Pupa of the fruit- 

 tree leaf-roller. 

 Knight photo. 



of a miscible oil, one part in 19 parts of water, made early in the 

 spring while the trees are dormant. Efficient work against the 

 eggs can also be done with a 10 per cent kerosene emulsion 



whenever for any reason it 

 is undesirable to use a mis- 

 cible oil. In case the eggs 

 have not been treated it is 

 necessary to resort to arsen- 

 ical sprays to kill the young 

 caterpillars. Use arsenate 

 of lead, 6 pounds in 100 

 x. en T7 -^ ^ 1 r n .u gallous of watcr, making the 



Fig. 69. — Fruit-tree leaf-roller moth. ° ' ^ 



Knight photo (x 2|). first application just as soon 



