236 THE CANADIAN ENTOMOLOGIST. 



the English sparrow into that city. Other species occasionally increase 

 largely in certain seasons for some unknown cause. On Mount Desert 

 one season I saAv myriads of the Pretty Pine Spanner, Cleo7-a pulchraria^ 

 which is not usually so plentiful. Some of the principal species which 

 injure our cultivated plants are the Army Worm, HeliophUa unipuncta; 

 tlie Cotton Worm, Aletia argillacea; the Cabbage Cut-worm, Hadena 

 devasfatrix, and other Cut-worms belonging to the genera Agrotis and 

 Hadeiia. The pine trees are bored by the larvae of several moths, and so 

 with the hickories, as well as the fruit trees in our orchards. Some excel- 

 ent scientific work towards working out the natural history of all these 

 species has been done by the Department of Agriculture at Washington 

 and the various State Governments. Taking into consideration the 

 damage inflicted by these insects, it may be said that money is well spent 

 towards understanding all about these pests, and the way to abate them 

 is to understand their histories and modes of attack first. The fact re- 

 mains that in many instances we can do comparatively Httle to check the 

 ravages of insect pest ; we have them chiefly removed by the multiplica- 

 tion of their natural enemies. 



CORRESPONDENCE. 



COAL TAR FOR THE PLUM WEEVIL. 



Dear Sir, — Respecting the use of coal-tar in the matter of driving 

 awaj the plum-weevil about which Prof Claypole inquires (p. i8o), I 

 have seen it recommended several times, and perhaps the source of the 

 different commendations of it was Prof Alex. Winchell's paper. I have 

 tried the coal-tar and found it of no avail. Some have followed advice 

 published at one time, and applied the tar directly to the bark of the 

 trunk and branches and thereby destroying the life of the tree, as has 

 also been done with carbolic acid. All similar ways of fighting the plum- 

 weevil must be classed as parrying methods. Systems aiming at whole- 

 sale slaughter, permit me to say, I deem are more judicious. There are 

 at least two very reliable extermijiati?ig methods in use against the pest, 

 both of which are explained by Mr. B. Gott in his article on the " Plum 

 Curcuho," in Annual Report of Entomological Society of Ontario, 1879. 



Very respectfully yours, 



Clyde, N. Y. W. L. Devereaux. 



