33 



THE MAPLE TREE SESIID. 



Sesia acerni, Clem. 



This is another caterpillar borer, found in soft maples more gen- 

 erally. It malces round holes, not over one-eighth of an inch in diam- 

 eter, in the solid wood, and the caterpillar is white, or nearly so, with 



short, stiff hair on the surface. It 

 comes to maturity in spring, and some 

 time during the latter part of May or 

 June forms its pupa near the outer 

 surface of the trunk. When ready to 

 change to the adult stage, the pupa 

 wriggles out for about half its length. 

 Just as the pupa of the leopard motli 

 does, and, usually very early in the 

 morning, the moth emerges. This is 

 rather a handsome little creature, yellow 

 with red trimmings and bandings, the 

 wings thin and transparent. It is one of 

 the "clear wings" and looks more like a 

 wasp than a moth. Sometimes maples 

 are infested by a large number of these 

 insects, but experience indicates that 

 little real harm is done to the trees, 

 provided water does not get into the 

 holes to cause decay. The borings are 

 in the heart-wood only, and as the heart-wood has little to do with 

 the actual nourishment of the tree, there is no immediate weaken- 

 ing. Where the insects are observed in numbers it will pay to white- 

 wash the trunks several times during the season. This will be 

 effective— first, by repelling the moths that would otherwise oviposit 

 on the trunks; and, second, it -.vill cover over or partly fill the small 

 holes that have been made by the insects. A tree once infested will, 

 under ordinary circumstances, remain infested, and there seems to be 

 an individual attraction that does not extend to even neighboring trees 

 of the same species. 



The maple tree seaild : o, the larva ; 



cocoons In cavities made by larva ; 



c, the adult moth ; d, pupa shell 



projecting from trunk. 



After BUey. 



