FOOD PLANTS OF PLATYSAMIA CECROPIA. 213 



leaves of this peach I had often placed young cecropia larvse, invari- 

 ably they refused to eat and starved to death. Twice I put larvse 

 about half grown, with the same result. 



When the larvte on the plum were about half gi'own, a gale of wind 

 blew the branches of the trees together. A few, days afterwards I 

 noticed the upper shoots of the peach denuded of leaves. On close 

 inspection I found four cecropia larvse — having evidently worked over 

 from the plum — feeding greedily and thriving well. These all 

 matured and spun upon the peach. 



The horse-chestnut is entered from finding eight cocoons so situated 

 that the larvse could not have fed on any other tree. 



The Symphoricarpus vulgaris is entered from one convincing 

 example — the shrub was isolated a long distance from any oth^r 

 shrub or tree — the cocoon was fovmd soon after completion, and 

 several shoots denuded of leaves gave evidence of the presence of the 

 larvse. 



Some doubts have been expressed as to the elm being a food plant. 

 The repeated finding of cocoons, often 30 ft. or more from the ground, 

 seems quite conclusive, but for several seasons I have reared a large 

 number of larvfe on an elm tree in my garden and the only noticeable 

 difference was the generally small size of the cocoons. Cocoons are 

 sometimes found on the common privet, but, although it is most pro- 

 bably a food plant, in absence of sufficient evidence it is omitted from 

 this list. , 



T have no doubt it will be found that the larvse feed indiscriminately 

 on all our species of willow and poplar. 



In all our northern lumbering sections, a few years after the s'^eep 

 of a bush fire, you find a dense growth of sambucus birch and willow. 

 Thus, with abundance of food and absence of parasites, this would be 

 the Cecropia's paradise, were it not for the woodpeckers which per- 

 forate the cocoons and feed on the pupse during the winter. 



I am indebted to Mr. E,. Morey and Mr. W. Squires for valuable 

 assistance in the collection of material for this list. 



