292 Transactions.—Zoology. 
family continue in the larva state for several years before transformation to 
the pupa, and it is probable that such is the case with the two species we are 
now considering. The perfect insect feeds upon the leaves of various trees, 
but I do not think that any serious injury in that respect has yet occurred in 
this province. Dr. Carpenter, in his work on zoology, revised by Mr. Dallas, 
referring to the cockchafers, says, “Their excessive multiplication is usually 
prevented by birds ; but if these be kept away they increase very rapidly and 
become a complete pest to the cultivator. The perfect insects sometimes make 
their appearance in such swarms as to devastate an entire forest.” 
A species of Aphis appears to have become very injurious to our corn 
crops, and we all know what pests we have in two other species, the one 
Aphis lanigera, commonly called “ American blight,” which infests the apple 
trees, and the other the “cabbage blight.” 
In addition to moths, beetles, and Aphides I may mention locusts and 
grasshoppers, the latter of which are very abundant on the plains, and devour 
a considerable quantity of grass and herbage. Fortunately for us the locusts 
are not yet so numerous as to do any considerable mischief, but I have noticed 
their increase of late years. These insects are so well known in their perfect 
state that I may pass over them with the single remark that their larve and 
pupe resemble the perfect insects, except that the wings of the pupa are 
rudimentary only and the larve have none. 
There is also a most destructive species of saw-fly, identical either with 
Selandria cerasi, or the North-American “ slug-worm,” or closely allied 
thereto. The larva of this fly is covered with a greenish-black viscid matter 
which exudes from its body, and to a cursory observer resembles a small black 
slug. It feeds upon the upper surface of the leaves of its food plant. Cherry, 
plum, pear, hawthorn, and sometimes other trees, become completely stripped 
of their leaves by these larvæ, and when it occurs early in the summer, as it: 
frequently does, the trees are compelled to put forth fresh foliage, thereby 
weakening them, and lessening the production of fruit in the succeeding year. 
Lastly, there is an insect which appears identical with, or allied to, Coccus 
arborum linearis. It infests the pear and ash, and some other trees, and has- 
the appearance of a small scale shaped like a mussel-shell. These insects 
thickly cover the bark of the trees, to which they closely adhere and exhaust 
the sap. 
Such as I have above described are, I believe, the most injurious of the 
insects we have to contend with, but there are numerous others of minor 
importance that I must defer for future observation. 
We will now proceed to the consideration of the expediency of introducing 
insectivorous birds and animals asa remedy. 
The increase of insects is so enormous and rapid, and their location so 
