Q4 MISC. PUBLICATION 278, U. S. DEPT. OF AGRICULTURE 
The elm leaf beetle (Galerucella xanthomelaena Schrank) (G4. 
luteola Mull.) is an introduced pest which has proved to be very 
destructive to elms. Since 1834 it has gradually extended its range 
to include nearly all parts of the country where elms are grown. 
Trees are weakened and subject to attack by various boring insects 
or are killed outright by repeated defoliations. The adults are one- 
fourth inch in length and dull olive green with a black stripe on each 
elytron. The larvae are blackish yellow and about one-half inch long 
when full grown. Park and shade trees can be protected by spraying 
with arsenicals soon 
after the new leaves 
open in the spring. 
The western wil- 
low leaf beetle (Ga- 
lerucelladecoraSay ) 
1s a dull, yellow- 
brown to black na- 
tive species that feeds 
on the leaves of wil- 
low and poplar 
throughout the 
country. 
The cottonwood 
leaf beetle (Lina 
scripta F.) (fig. 47) 
is found throughout 
the country, feeding 
on the leaves of wil- 
low and poplar. In 
New York it is very 
destructive to wil- 
lows raised for bas- 
ketwork, and often 
heavily defolhates 
these trees in the 
West. The adults 
are yellowish marked 
Piet 7 Chee a lenpipectie: (id ne with black spots and 
IGURE 47.—Cottonwood leaf beetle (Lina scripta): A, Fe- ‘ 
male beetle, X 5; B; male bectle. < G:C, larval’ B:. are ADOUL One Lourtn 
ee pune a . 5; H, eggs on cottonwood leaf; F, skeletonized jneh in length. : They 
appear early in the 
spring and feed on the tender shoots. The eggs are yellowish or 
reddish and are deposited in clusters on the under surface of the 
leaves, and it is here that the black grubs feed as soon as hatched. 
The period of growth to the mature larval stage is about 15 days in 
hot weather. Five generations a year are reported in the West. - 
L. tremulae F. feeds on aspen and poplars in the Pacific Northwest. 
The willow leaf beetle (Lina interrupta F.) is similar to the above, 
but smaller. It feeds on willow and ranges from California to 
Alaska. Another species, Z. californica Rogers, is black to bluish 
“green and feeds on willow in California. 
The spotted willow leaf beetle (Lina lapponica L.) is sometimes 
as prevalent and just as injurious to willows and poplars in the 
