30 



Its colour is deep black, with the exception of the thorax above and the front purt of the 

 breast beneath, which are rusty yellow ; on the thorax there are three small elevated black 

 dots, arranged in a triangle (not two only, as in the figure), whence is derived the specific 

 name of the insect. The antennae are nearly, if not quite, as long as the body. The beetles 

 are usually found in July and the beginning of August ; they attack all the varieties of 

 raspberry, and come into gardens from the fields and clearings, where we have often taken 

 specimens and observed their work. The mode of attack is peculiar ; the first appear- 

 ance of injury is usually manifested by the withering and drooping of the ends of the 

 young shoots. On inspection, it is found that at the base of the affected part there are 

 two rows of punctures, half an inch apart, running completely round the canes, and so 

 girdling them that the supply of sap is stopped and the tops necessarily soon wither and 

 break off. The parent insect begins by cutting with its jaws a series of small punctures 

 side by side around the cane, six or seven inches from the top. As soon as the first row 

 is completed, it turns round, and facing the other way, cuts a second row, measuring the 

 length of its own body. These two girdles being completed, it makes a small hole a little 

 way above the lower girdle, and deposits in it its small yellow egg. The whole operation 

 occupies an hour or more. Prom this egg there hatches out in a few days a small, yellow, 

 footless grub, which proceeds to burrow downwards, eating the pith of the cane and even- 

 tually causing its destruction. 



In our Entomological Report for 1873, Mr. Saunders gives a fall, scientific description 

 of the larva of this insect and many other interesting particulars to which we beg to 

 refer the reader. Though certain that the girdling of tiie raspberry canes was caused by 

 this insect, he states that he had " not yet seen the beetle in the act of depositing their 

 eggs " and making the girdles. We are glad to be able to complete the life history of the 

 insect by the account we have given above, which is taken from repeated observations that 

 we made ourselves several years ago at Cobourg, the substance of which we embodied in an 

 article in the Canada Farmer of 1869 (page 358). The object of this singular girdling 

 operation is, in all probability, to check the growth of the cane, and so prevent the crushing 

 and destruction of the egg or larva by the rapid increase of cells and tissues in the plant. 



An obvious remedy for the injuries inflicted by this insect is to break oS at the lower 

 girdle and burn the affected twigs, as soon as possible after they are observed to wither ; 

 the egg or newly-hatched larva will thus be destroyed and the increase of the species 

 checked. 



In the foregoing description of the wood-boring beetles figured on our plate, our aim 

 has been, not to write an original dissertation upon the insects, but to gather together 

 from various sources, as well as from our own observations, all the information respecting 

 them that we have thought would be of interest or value to the readers of these Reports. 

 We hope that the beauty and graceful forms of the insects will lead many of our country 

 friends to collect for themselves, and then study the life history of these wonderful denizens 

 of our groves and forests. 



