Insects Injurious to the Fruit of the Apple 



1911 



will begin feeding on the leaves and the blossoms, and in this way a 

 person is easily able to determine which species is present. " 



the fruit-tree leaf-roller 

 Ar chips argyrospila Walker 

 For some years past, in Colorado and Missouri orchards this leaf 

 roller has been one of the most serious insect pests with which apple 

 growers have had to contend. It has been found in New York State 

 since 1874, and in 1888 and 1892 it was recorded as injuring apples and 

 pears to a slight extent, but it was not until 191 1 that it suddenly became 

 a serious apple pest. During the spring of that year the 

 insects appeared in very large numbers in an orchard in 

 Genesee County and in varying numbers in many other 

 orchards in the State. Since then it has been increasing 

 in importance as an apple pest, until during the past 

 season it caused more or less injury in most orchards 

 throughout the apple-growing sections and was very 

 injurious in certain widely separated orchards in western 

 New York. 



The fruit-tree leaf-roller, though an apple pest, by no 

 means confines its attacks to this fruit. It is also very 

 destructive to pears and has been found feeding in this 

 State on sweet cherry, wild cherry, plum, quince, black 

 v^^alnut, and mountain ash. In the West it has been 

 Fig. 117. — Egg observed on rose, currant, gooseberry, apricot, Osage 

 Tree^ leaf -roller, orange, box elder, sassafras, and hazel, in addition to its 

 showing holes more common orchard food plants. It has also been 



through which 



collected from a number of different kinds of shade and 



the young cater- 

 pillars emerged, forest trees. 



^ ^^^^ Although this insect is not equally injurious from year 



to year in any given locality, on account of its wide range of food 

 plants it is easily able to maintain itself in a section until such time as 

 conditions are favorable to its rapid increase. It may then suddenly 

 become one of the most serious pests with which the apple grower has 

 to deal. 



Life history. — This insect spends the winter in the egg stage. The 

 eggs are laid on the smaller twigs and frtiit spurs in small oval, flat, 

 grayish patches, about one-fourth inch in diameter (Fig. 117). The 

 average ntmibcr of eggs in one of these masses is about one hundred and 

 fifty though this often varies considerably. Each egg mass is protected by 

 a smooth varnish-like substance. In New York State the eggs hatch 

 just as the buds are bursting, and by the time the blossoms show pink 



