SUMMARY OF THE HABITS OF THH FOUR SPECIES. 
It follows from the above that we have to deal with four very different 
insects, each of them requiring modification in treatment, especially so 
far as winter work is concerned. Here, as in every other case in deal- 
ing with injurious insects, correct knowiedge of the habits of the species 
to be dealt with must necessarily precede intelligent action, else we shall 
be apt to err, as did the authorities of our neighboring city, Baltimore, 
many years ago, by incurring a great deal of unnecessary expense with- 
out producing any beneficial result. Their blunder is historical. Ob- 
serving that the elm trees around Cambridge, Mass., suffered from de- 
foliation and were effectually protected by troughs of oil around the 
trunk, they ordered similar troughs of oil to be placed around their 
trees in Baltimore, which were also being defoliated. In Cambridge, 
however, the insect involved was the Spring Canker Worm (Paleacrita 
vernata), which has a wingless female that issues from the ground early 
in spring, and is effectually prevented by the oil troughs from ascend- 
ing the trees; whereas the trees in Baltimore were suffering from the 
Galerueca, which we have just described, and which has ample wings in 
both sexes. 
1. The imported Elm Leaf-beetle is a small yellowish beetle, about a 
quarter of an inch long, and marked with two longitudinal dark stripes 
on the back. It passes the winter in the beetle state in holes and crey- 
ices in the bark of trees, in fences and tree-boxes, in barns and out-houses, 
eic., and the eggs are laid on the young leaves of elmsin April and May. 
The eggs are yellowish, elongate, and pointed, and are laid on end upon 
the leaves in groups of from five to twenty or more. The resulting 
worm feeds on the leaves, gradually skeletonizing and gnawing holes 
through them. The larve molt four times and transform to pups at the 
surface of the ground under grass and stones. There are several broods, 
and and the worms are pretty constantly at work through the months 
of June, July, and August. 
This is an imported insect, is confined to the Elm (genus Ulmus), has 
a predilection for the European Elm and for trees in cities, and the fe- 
male flies long distances. 
2. The Bag-worm is one of our commonest native American insects, 
and its bags hang from the smaller limbs of our shade trees so as to be 
easily seen, especially in winter, wnen the leaves have failen. These 
bags are made by the larva or worm which lives within them. The 
female moth is wingless, and only leaves the bag in which she passed 
her larval and pupal life after she has deposited her eggs in her empty 
59 
