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 Ai^hides I may mention locusts and 

 grasshojDj^ers, 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 larvae and 

 pupse resemble the perfect insects, except that the wings of the pupae are 

 rudimentary only and the larvae 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, 

 l^lum, pear, hawthorn, and sometimes other trees, become completely stripped 

 of their leaves by these larvae, 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 

 arhorum 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 as a remedy. 



The increase of insects is so enormous and rapid, and their location so 



