50 Farmers’ Bulletin 1169. 
in the Middle West, the injury of these insects assumes lively im- | 
portance. 
Appearance and habits —Attention is drawn to the insect by hack- 
berry leaves which show signs of being eaten away, and green cater- 
pillars with pale spots and lines along the back and projections on 
head and rear (fig. 30, 6) are found on the underside of leaves. The 
caterpillars change to chrysalids (fig. 30, c, d) in folded leaves and 
‘ater to russet-gray, brown-spotted buterflies (fig. 30, ¢), which, after 
mating, lay their eggs singly (in one case, fig. 30, a) or in batches of 
300 to 500. Two generations 
are produced annually, the sec- 
ond-stage caterpillars of the | 
last generation falling to the 
ground with the leaves they 
are on and passing the winter 
there. 
Fig. 31.—Streaked cottonwood leaf-beetle F 
(Melasoma scripta), showing variation in Remedies.—The leaves may 
markings. (Riley.) 
be raked up and burned in the 
fall or the infested trees sprayed with lead arsenate (p. 11) while the 
caterpillars are feeding. 
COTTONWOOD, POPLAR, AND WILLOW LEAF-BEETLES.” 
How injurious—Poplar, cottonwood, and willow leaf-beetles are 
particularly injurious because their adults as well as young or larve 
derive their nourishment from eating the leaves of these trees, and, 
as they produce from three to five generations annually, they are 
capable of keeping the trees in a constant state of defoliation. They 
are most prevalent in the Northern States, are occasionally seriously 
injurious, especially to basket willow in the East, and are an almost 
constant drain on the health of these trees in the Middle West, where . 
tree life is so scarce and precious that injury to it is intolerable. 
How recognized.—Infestation is indicated by leaves of these trees 
bitten part way through in places and entirely through in others 
early in the season, and entirely consumed later by spotted, soft- 
bodied, short, stoutish grubs and spotted or striped, half-inch long, 
hard-shelled beetles (fig. 31), mostly on the underside of leaves where 
also batches of yellow or reddish eggs standing on end and pupe are 
to be found. The young when disturbed emit a millxy fluid. 
Habits —The overwintering beetles appear in the spring as soon 
as growth starts on these trees and promptly begin eating this growth. 
After feeding awhile they lay clusters of eggs from which the soft- 
26 Melasoma scripta Fab., M. lapponica L., M. tremulae Fab., and others, 
