106 TRANSACTIONS OF THE ILLINOIS 



strength of solution would be sufficiently effective. The spraying o£ 

 large-sized nursery stock, though under the present system attended 

 with mechanical difficulties which are elsewhere discussed, would 

 certainly repay the cost. For young trees in the orchard such 

 spraying is a very simple matter, and its neglect where needed is in- 

 excusable. 



THE LESSER APPLE LEAF-ROLLER. 



Teras Minuta, Robs. 



This insect has been known as a serious pest in Illinois for more 

 than twenty years, and I think must rank first in the list of leaf- 

 eating nursery insects. Commencing as soon in spring as the leaves 

 begin to put forth, and affecting almost wholly the terminal portion 

 of the young tree, the amount of damage which these larvae are 

 capable of doing during the season is simply immense. Of course 

 the effect of their injury is to stop that straight upward growth 

 which is the sine qua non of the successful nursery tree, and to cause 

 the tree to throw outside branches, giving it a stunted, scraggy- 

 appearance that greatly lessens its value either for planting or dis- 

 tribution. This pest seems pretty generally distributed throughout 

 Illinois, as we have obtained it in Cook, McLean and Marion coun- 

 ties. 



LIFE HISTORY. 



The Jife-history of this species is very remarkable because of the 

 different colors of the moths of the different broods, the moths of 

 the two summer broods being orange and those of the autumn brood 

 gray. This is an instance of what naturalists call dimarphism, and 

 is the only instance of the kind known in the family to which the 

 insect belongs. 



Briefly summarizing our present knowledge of the species as re- 

 gards the apple, its life history may be outlined as follows: The eggs 

 are laid in spring on the unfolding leaves, the larvae soon hatching 

 to devour the tender foliage of which they form a protective case, in 

 which they continue feeding for about a month, when they pupate 

 within the folded leaves, and a week or more later emerge as yellow 

 moths. These moths lay eggs for another brood of larvae, the im- 

 ages from which appear in August, being again of the same yellow 

 color. These in turn lay eggs for a third brood of worms which de- 

 velop during September, and emerge as glistening reddish gray 

 moths in October, to pass through the winter in various rubbish 

 heaps, fence corners, and similar places of protection and conceal- 

 ment, and deposit eggs on the unfolding leaves the following spring. 

 Thus is completed the remarkable cycle of insect life — one of the 

 most curious to be found recorded in the literature of entomology. 



