INJURIOUS INSECTS. 65 
Very soon after this if we examine the trees we shall sev the 
eggs of which every female lays some sixty or a hundred,’ 
glued over, closely arranged in rows and placed in the forks of 
branches and among the young twigs. About the twentieth of 
May, these eggs ara ledober, and the canker worms, dusky brown, 
or ash-coloured with a yellow stripe, make their appearance and 
commence preying upon the foliage. When they are abundant 
they make :rapid progress, and in places, where the colony is 
firmly established, they will sometimes strip an orchard in a few 
days, making it look as if a fire had passed over it. . After feed- 
ing about four weeks, they descend into the ground three or four 
inches, where they remain in a chrysalis form, to emerge again 
the next season. As the female is’ not provided with wings, 
they do not spread very rapidly from one place to another. 
The attacks upon the canker worm should be chiefly made 
upon the female, in her way from the ground up the trunk of 
the tree. 
The common mode of protecting apple trees is to surround 
the trunk with a belt-or bandage of canvass, four or five inches 
wide, which is then thickly smeared with tar. In order to prevent. 
the tar from soon becoming dry and hard, a little coarse train oil 
must be well mixed with it; and it should be watched and re- 
newed as often as it appears necessary. This tarred belt catches 
and detains all the females on their upward journey, and prevents 
them from ascending the tree to lay their eggs. And if kept in 
order it will very etfectually deter and destroy them. When 
the canker worm is abundant, it is necessary to apply the tarred 
“bandage in October, and let it remain till the last of May, but 
usually it will be sufficient to use itin the spring. It is probable 
that a mixture of coal tar and common tar would be the best 
application; as it is more offensive and will not so easily dry 
and become useless, by exposure to the air and sun. Some 
persons apply the tar directly to the stems of the tree, but this 
has a very injurious effect upon the trunk. Old India rubber, 
melted in an iron vessel over a very hot fire, forms a very adhe- 
sive fluid which is not affected by exposure to the weather, and 
is considered, by those who have made use of it, the best sub- 
stance for smearing the bandages, as being a more effectual bar- 
rier, and seldom or never requiring renewal. 
Mr. Jonathan Dennis, jr. of Portsmouth, Rhode Island, has 
invented and patented a circular leaden trough, which surrounds 
the trunk of the tree, and is filled with oil, and stops effectually 
the ascent of the canker worm. There appear, however, to be 
two objections to this trough, as it is frequently used; one, the 
escape of the oil if not carefully used, which injures the tree ; and 
the other, the injurious effect of nailing the troughs to the bark 
or trunk. They should be supported by wedges of wood driven 
in between the trough ad the trunk, and the spaces completely 
