STATE HORTICULTURAL SOCIETY. 105 



eatiug the parenchyma of the upper surface of the leaves, as they 

 grow ohh'r s])iiining a slight jiroteetive silken web on the leaf be- 

 neath which they continue their destructive work. When full 

 grown they vary from an olive or pale green color to brown, are 

 about half an inch long, and have four black shining tubercles ou 

 the back just behind the head. About midsummer the larviu pu])ates 

 in slight cocoons, formed usually on the leaf, and about two weeks 

 later the moths emerge. Eggs are laid by these for the second 

 brood of larva?, which form cocoons before winter sets in and hiber- 

 nate as pupate, the moths from them emerging the following spring. 

 But this species is very irregular in its development, it being easy to 

 find larviv of nearly all ages almost any time during the season. 

 The second brood is more numerous than the first, and consequently 

 the injury is most noticeable during September and Octo1)er. The 

 fact of the two brooded ness of tiie insect is one of the discoveries of 

 the office during the past year, it having been heretofore supposed to 

 be single brooded. 



It is jirobable that, left to its own resources, this insect would 

 spread very slowly, but that there is great danger of its being carried 

 from place to place through the agency of man there can be little 

 doubt. ?]specially is it liable to be introduced with trees from the 

 nursery, unless great care be taken to thoroughly strip them before 

 sending out, and also to see that no dead leaves cling about the 

 roots or get into the packing boxes. A case in point is that of a 

 fruit grower in Sangamon County, Illinois, who purchased trees 

 from nurseries infested by the species and was afterwards greatly 

 troubled by their presence. So far as can be learned the insect had 

 not been observed before in the locality in c^uestion. 



REMEDIES. 



Concerning remedies Prof. Riley says: "A little handpicking 

 at the proper time would do much to prevent its injuries, and I in- 

 cline to believe that it may be extirpated by dusting the tree with 

 air-slacked lime." Prof. French has added the recommendation that 

 the arsenites be used, which have also been recommended by I^rof. 

 Forbes, who has in addition recommended that the fallen leaves be 

 burned to destroy the puj)ate. Hut none of the writers seem to 

 have known of any practical experiments made to test the value of 

 the substance recommended. 



Early in .July the past season I made, under the direction of 

 Prof. Forbes, some experiments with Paris Green on skeletonizer 

 larvae infesting nursery trees. The result showed that spraying with 

 Paris Green in the jiroportion of one ounce to eight gallons of water 

 efEectuall.y destroys the larva- without injury to the tree; and from 

 some partial exp?riments made at the same time, which were inter- 

 rupted by a heavy rain storm, 1 incline to believe that half this 



