CANADIAN FORESTRY ASSOCIATION. 39 



name of Quadricornis. There are peculiarities in the form and habits of the larvae 

 of this species that are well worth notice. 



You will remember 'that the leaves of the elm on the underside are strongly and 

 regularly ribbed; and that they are often curled over on one side in a roll. The 

 Amyntor caterpillars are of the same colour as the leaf; and, along the sides they 

 have seven oblique, raised, rough lines. They lie extended along the edge of the leaf, 

 and in that position very closely resemble the roll of the leaves near them. Nor is 

 this all: in the autumn the leaves of the elm become rusty-brown in colour; and, 

 that the resemblance to the leaves may be maintained, the caterpillars become of the 

 same hue. They afford in this a remarkable instance of what is called Mimetic 

 Analogy. 



The larva of that stately moth, Triptogon modesta, Harris, feeds upon the poplar; 

 and that of Cressonia juglandis, S. & A., upon the black walnut, the butternut 

 and the hickory. 



Upon a variety of forest trees, the larvae of those magnificent Saturnians, 

 Attacus Cecropia, Linneus (the largest of our moths), and Telea Polyphemus, Cramer, 

 are to be found; whilst those of Actias Luna, Linneus, (the most beautiful of all our 

 moths) feed upon the butternut; and those of Hyperchirea lo, Fabricius, upon the 

 elm, the bass-wood, and the balsam-poplar. The last named larvae are set with sting- 

 ing spines. 



In the west the larva of that splendid moth Eacles vmperialis, Drury, feeds upon 

 the white pine; and the larva of Citheronia regalis, Fabricius which has as many 

 horns as the Beast in the Apocalypse, and is locally known as the ' Hickory Horned 

 Devil' feeds upon the black walnut, butternut and hickory. 



I have never heard, however, that the caterpillars of these very large insects have 

 done very much damage. 



Of insects that injure the roots of the trees, these call for our attention : 



The White Grub, which is the larva of the May Beetle, Lachnosterna fiteca, 

 Frohling. The grubs of this species are very general feeders upon the roots of plants. 

 They have been found exceedingly injurious to young pines and tamaracks. 



A formidable foe to the poplar, basswood and oak is Prionus laticollis, Drury, the 

 Broadnecked Sawyer, which bores into the roots of the trees. I have not found it at 

 Quebec ; but I have seen a specimen that was taken at Sherbrooke. As it works under 

 ground, its ravages are not easily detected. 



But of the underground insect foes of the forest trees, the Cicadas are, I think, 

 the worst. Happily this part of Canada is out of the range of Tibicen septendecim, 

 Linneus, which spends seventeen years at the roots of trees, imbibing at the very 

 founts of vegetable life. But Cicada canicularis, Harris, is very abundant in these 

 parts . If you go into the woods in autumn you will hear the shrill sound produced 

 by their little tambours or side drums whch vibrate, as the boys say, ' for all they 

 are worth/ 



We have another species of Cicada, Tibicen rimosa, Say, but it is not common 

 with us. 



The habits of the Cicadas are interesting. The females cut grooves in the twigs 

 of their favourite trees; and in each groove lay a row of eggs. The eggs seen) to be 

 nourished by the sap in the twigs, for they become enlarged. The newly hatched 

 larvae drop to the ground, and burrow till they reach the roots of the trees. Into 

 these they drive their beaks, and then, for three years, live, by suction, upon the sap. 

 At the end of that time they work their way out of the earth, climb for a short dis- 

 tance up the trees, and then writhe and twist, till their skins burst down the back. 

 Out of the rent, in every case, creeps a perfect insect, drawing its legs out of their 

 former enclosures, as out of boots. In about ten minutes (I have watched the pro- 

 cess), the air has penetrated to every part of the insect's body; its winprs have been 

 shaken out of plait, into their full dimensions; and the creature is ready for flight. 



If you ask me, what should be done to check the cicadas? Well, I know what I 

 .should do as regards the orchards, the suerar-bush. and the inclosed wood*. T should. 



