Generation of Sounds by Canadian Insects. 123 



Tree-hopper. * Drums of Tree-hopper. 



(Cicada canicularis.) a a the outer drums ; b the muscular 



Natural size. strings ; c c the inner drums. 



This insect is not a grass-hopper, as its name is erroneously trans- 

 lated from the writings of Pliny and others, but belongs to the first 

 family of the Homopterous Hemiptera. It has a pair of transpar- 

 ent wings and wing covers, and a shining black body ; the largest 

 Montreal specimens measure 3 inches and 3 lines with extended 

 wings, and the body 9 lines and-a-half. Their general expansion 

 is from 1\ to 3^ inches, and the veins of the wings are of a green 

 and orange colour. They are not found in such large numbers 

 in Canada as in the United States, where it is said such immense 

 numbers are sometimes congregated, as to " bend and even break 

 down the limbs of trees by their weight, and the woods resound 

 with the din of their discordant drums from morn to eve." On 

 the most careful comparison between the Canadian and European 

 species of this insect, I find there is not the slightest appreciable 

 difference in the formation of the musical instrument or particular 

 organ, which is present in the males only on each side of the 

 base of the abdomen, by means of which is produced a sort of 

 monotonous and noisy music, which has led to their being termed 

 by many authors " chanteuses " or singers. 



It consists of 2 pairs of large plates fixed to the trunk between 



* Several species of Cicada inhabit the United States and Canada. 

 The Larvae live under ground on the roots of trees to which they are 

 occasionally injurious. Dr. Harris in his treatise " On Insects injurious 

 to Vegetation," gives an interesting history of the above and several 

 other species. — Eds. 



