NOVEMBER, 1910 



CIRCULAR No. 8 



CORNELL UNIVERSITY 



AGRICULTURAL EXPERIMENT STATION OF 



THE COLLEGE OF AGRICULTURE 



Department of Entomology (Extension Work) 



Fir, 



THE ELM LEAF-BEETLE 



GLENN W. HERRICK 



About 1834 there was introduced into the city of 

 Baltimore, from somewhere in Europe, a small in- 

 conspicuous beetle whose food plant at home had 

 been the European elms. It attracted no particular 

 attention until about four years later, when it came 

 into prominence as a serious enemy of the elms in 

 this Maryland city. Since that time it has gradually 

 extended its territory until now it is found as far 

 north as Massachusetts and New York and westward 

 to Ohio and Kentucky. In 

 \n adult N GW York State it is destruc- 

 eim leaf-beetle. tive in the eastern and cen- 

 tral sections, and very likely 



will gradually extend its activity until it 



covers the greater part of the State. 



THE APPEARANCE OF THE BEETLE, AND ITS 

 WORK 



The insect is about one-fourth of an inch long. 

 In general, it is yellowish or brownish yellow 

 in color, with a dark line along each side of 

 its back (Fig. i). Its color varies somewhat, 

 and the over-wintering beetles are often so 

 dark colored that the brownish yellow almost 

 disappears and the black lines are hardly * 

 noticeable. In its normal coloring it is quite 

 likely to be confused with the common striped 



cucumber beetle, although it is considerably ^ 2 _ Adult beetles eating 

 larger. leaf in the spring. 



