HOKTICULTUEAL SOCIETY. 



169 



Fig. 1. 



Agrilus (A f/rilus ruf colli s.) (Fig. 1. ) This insect is a beetle, 



and belongs to that large family of 

 beetles whose larva? are so well known 

 l )y the Dame: "flat headed borers." 

 \Iost horticulturists in more southern 

 ;tates know to their sorrow how injur- 

 ious the flat-headed borers of the apple 

 rree may become in certain years and in 

 certain localities. Nor is this insect a 

 great rarity in this state, where it oc- 

 curs quite commonly in oaks. The 

 Red-necked Agrilus possesses the faculty of producing peculiar gall- 

 like swellings upon the canes infested by it. (Fig. 2) These galls 

 have received the name Raspberry Gouty Galls, from the fact that 

 the stems swell up in particular places as if troubled by the gout 

 yet this is not always the case, as I have frequently bred the insect 

 from canes that had been killed by them, yet 

 showed no perceptible swellings. The illustra- 

 tion before you shows such a gall. The cane, 

 instead of being smooth and of the same color as 

 the healthy parts, is swollen, and is further dis- 

 tinguished by many short, rough, longitudinal 

 slits. Numerous ridges may also be seen, which 

 run round and round the axis of the cane. If, 

 during autumn or spring, we cut into such ridges, 

 and follow the burrow underneath, we find under 

 each a little yellowish- white larva. This larva is 

 distinguished from other larva? occurring in- 

 side the cane, by having the body much flattened 

 out horizontally. Its small head is retractile, and 

 has brown jaws; a tail furnished with two long 

 and slender dark brown thorns, as indicated in 

 the illustration, is also quite characteristic. The 

 size of this larva, if full grown, ranges from one- 

 half to three- quarters of an inch. As the larva? 

 burrows exclusively in the sapwood, it frequently 

 girdles the cane, thus killing it. Each gouty gall 

 contains most frequently a number of such larva?, 

 and some of the canes investigated contained as 

 many as seven. Towards fall the full-grown 

 larva penetrates into the pit, where early in 

 spring it transforms into a pupa. 

 The winged beetles appear at about the time that raspberries 

 and blackberries are in full bloom. They now mate, and soon af- 

 terwards deposit their eggs for another generation. These eggs 

 are laid in or upon the young canes, and the young larva? soon af- 

 ter produce other gouty-galls. The beetle is a slender and rather 

 pretty insect. It is characterized by a brilliant coppeiy color upon 

 head and thorax. Its body and hard wings are velvety black. 



These borers infest both raspberries and blackberries, but rather 

 prefer some of their numerous varieties. 



Fig. 2. 



