84 



INSECTS AND HUMAN WELFARE 



is presented by several insects that affect the elm in New 

 England. Since the history of the insects concerned is so 

 well-known and the sequence of events so clearly marked, I 

 cannot refrain from considering the matter in some detail. 



In the late thirties of the last century there appeared in 

 America near the city of Baltimore, a small European beetle 

 known as the elm leaf-beetle (Galerucella luleold) which feeds 



FIG. 37. The leopard moth (Zeuzera pyrina), an imported shade tree pest. 

 Work of the larva in a branch from which the bark has been removed; above, 

 the larva. 



upon the foliage of various elms. The adult beetles feed on 

 the leaves of the elm and are especially attracted to the Amer- 

 ican elm. Later they deposit their eggs upon the leaves which 

 serve as food for the larvae. Two or three successive broods 

 develop in a single season and greatly weaken the elms 

 affected. The elm leaf-beetle has gradually spread till it is 

 now present generally throughout the more temperate sec- 

 tions of eastern North America. 



Many years later, in 1890, there was noticed on Long Is- 

 land another European insect of very different appearance 

 and habits, the leopard moth (Zeuzera pyrina) (Fig. 37) . This 

 insect is a large moth which feeds in the larval stages in the 



