SUMMARY OF HABITS OF THE FOUR SPECIES. He 
maggots obtained from caterpillars kept for this purpose in breeding 
jars changed to the fly in six days; others appeared in twenty-three 
days, and still others, obtained at about the same time, are still under 
ground, where they will hibernate. The maggots of these flies do not, 
however, always enter the ground, as some were found inside cocoons 
made by caterpillars among rubbish above ground.”* 
SUMMARY OF THE HABITS OF THE 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 knowledge 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, Balti- 
more, many years ago, by incurring a great deal of unnecessary expense 
without producing any beneficial result. Their blunder is historical. 
Observing that the elm trees around Cambridge, Mass., suffered from 
defoliation aud 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 
Galeruca, 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 
crevices in the bark of trees, in fences and tree-boxes, in barns and out- 
houses, &c., and the eggs are laid on the young leaves of elms in 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 gnaw- 
ing holes through them. The larvze molt four times and transform to 
pupe at the surface of the ground under grass and stones. There are 
several broods, 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 
female 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 
*Just as this bulletin is going to press we have discovered another primary para- 
site in the old Department collection. It belongs to the genus Kuplectrus, and is near 
E. platyhypene Howard. 
