SUMMARY OF THE HABITS OF THE FOUR SPECIES. 



It follows from the above that we have to deal with four wry 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 kuowiedge 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 

 rernata), 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 crev- 

 ices in the bark of trees, in fences and tree-boxes, in barns and out-houses, 

 etc., 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 gnawing holes 

 through them. The larvae molt four times and transform to pupae 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 th< 

 male flies long distances. 



2. The Bag-worm is one of our commonest native American inse< B, 

 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 laden. 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 passi d 

 her larval and pupal lite after she has deposited her eggs in her empty 



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