156 Control of Parasites 
also colored and have well-deseloped legs, usually live on 
the leaves; the pupa generally and sometimes also the beetle 
wintering either underground or in the litter. The different 
species are more or less dependent on certain species of 
trees; willows, poplars, elms, also oaks and pines having 
their special pests. Here belong also the potato-beetle, 
the asparagus-beetle, and the cucumber-beetle. The most 
common and most destructive to ornamental trees is the 
imported — 
Elm-leaf Beetle, the beetle being yellowish brown to green- 
ish yellow with two or more black stripes on the wings. and 
the half-inch larva yellowish black with black spots and 
tufts of hair and wide yellow lines along the back and sides. 
The foliage is characteristically eaten, the soft tissue between 
the ribs being attacked in patches; the beetles eating irreg- 
ular holes, the grubs systematically skeletonizing. The 
grubs work on the under side of leaves from May until 
August, together with the one to three or four broods of 
beetles, which lay their yellow bottle-shaped egg clusters on 
the under side of leaves. The pupa winters under the 
fallen leaves near the base of the tree, and the beetle in all 
sorts of sheltered places; they attack the leaves in spring 
(April or early May) as soon as these are fully developed, 
beginning at the top of the tree. 
The many broods, the prolific reproduction, and the fact 
that both beetle and larva feed on the foliage, make this 
pest most injurious, since in one season it may destroy two 
or three sets of new foliage and exhaust the tree. 
Besides destroying the wintering beetles or pup, either 
mechanically or by hot water or kerosene, etc., spray with 
arsenites as soon as beetles begin feeding, a second spray- 
ing being applied when eggs begin to hatch or ten days 
later. Since the beetles are disinclined to fly, a single tree 
