36 



been found notably injurious only in southern and central Illinois and 

 in a limited district in central Ohio. 



2. It feeds in small numbers, as beetle or larva, on a consider- 

 able variety of native trees and shrubs, but is definitely injurious only 

 to the cultivated apple. 



3. The adult beetle is a shining black, densely punctate snout- 

 beetle, about a tenth of an inch long. It is readily distinguished by its 

 much thickened hind thighs and by its exceptional power of leaping, 

 like a flea, when disturbed. The white to brownish larva, found only 

 in leaf-mines, is flattened cylindrical, tapering from the middle towards 

 both ends. It is about a fifth of an inch long when full grown, and at 

 its widest part a fourth as wide as long. It hatches from an egg laid 

 in one of the thicker veins of the under side of the leaf, and feeds on 

 the leaf parenchyma, making a closed mine or burrow which is finally 

 expanded at its outer end into a blotchlike blister within which the larva 

 pupates. 



4. There is but one generation a year, the newly formed adults 

 of which emerge from their mines in May and June, feed on the leaves 

 for about a month, and then, in June and July, leave the tree to conceal 

 themselves in what are to be their winter quarters, under grass, leaves, 

 and rubbish on the ground. Here they remain until spring, leaving their 

 shelter at about the time of the unfolding of the leaf, creeping up the 

 trunks of the trees, or flying to the branches above, and beginning again 

 to feed on the leaves, in which eggs are presently laid for the next 

 generation. The egg period lasts about a week, that of the larva IT days, 

 and the pupal period 5 or 6 days. 



5. Injury is done by both the larval mines and the feeding-punc- 

 tures of the beetles, usually made in the under side of the leaf. The 

 maximum effect in badly infested orchards is a destruction of the leaf- 

 age suftrcient seriously to weaken the tree and reduce it to worthlessness. 



6. The principal natural checks on the multiplication of the 

 weevils are fungus and insect parasites, the former destroying the 

 beetles by wholesale in wet sunmiers and the latter killing the larvae. 



7. Experiments with means of control were made by banding the 

 tree trunks with tanglefoot, spraying or dusting the leaves with poisons 

 or with contact insecticides, burning the hibernating beetles in grass 

 and rubbish under the trees, poisoning them there with sprays and 

 poison dusts and by the use of poison baits, and cultivation of the 

 orchard at a time and in a way to bury the hibernating beetles beyond 

 resurrection or to keep the ground free from cover to which they might 

 retreat in summer for concealment and hibernation. 



Thoroughly clean cultivation, carried close to the tree, was the 

 most effective of these means, reducing formidable infestations to in- 

 significance and improving the vigor and productiveness of the trees. 



