REPORT OF THE COMMISSIONERS OF FISHEKIKS, CAME AM) FORESTS. 25 



usually penetrating about four inches in an upward, oblique direction toward the heart 

 of the tree and then running some distance parallel with the grain of the wood, as 

 represented in figure 9, which was drawn from a photograph. At the end of this deep 

 burrow the larva transforms to a pupa and from that to a beetle, the beautiful adult 

 emerging from the trunk through an oval hole (Plate 3, figure 5) about three eighths 

 by five eighths inch in diameter. 



The only natural enemies observed preying on this insect are woodpeckers. Dr. 

 Packard records having seen them at work. Mr. A. H. Kirkland has seen the hairy 

 woodpecker, the downy woodpecker and the flicker feeding on 

 white larvas taken from beneath the bark of infested trees 



Associated Insects. As previously pointed out, the sugar 

 maple borer attacks trees in their prime. It is well known to 

 students of nature that an enfeebled plant invites insect injury 

 by presenting favorable conditions for -their multiplication. 

 Trees suffering to any extent from the attack of the sugar maple 

 borer are usually infested with the pigeon Tremex, Tremex 

 columba Linn., a species which assists materially in the destruc- 

 tion begun by the beetle. The pigeon Tremex is a magnificent 

 four winged fly about two inches long, with a wing spread of 

 two and one half inches, and a prominent horn at the extremity 

 of the abdomen; hence the common name of "horn tail" is 

 frequently applied to this insect and its allies. This species may 

 be recognized by its cylindric dark brown abdomen with yellow 

 markings as represented in figure 10. 



~. * i j - . , . T. - Ffgure Q. Deep burrow in 



The larva or borer producing the pigeon Tremex may be which the grub trans- 

 distinguished at once from that of the sugar maple borer by the be " le 

 its cylindric form, the possession of six legs on the three anterior 



body segments and by its making a nearly round burrow. The perfect insects 

 make their way out of the tree through holes about the size of a common lead 

 pencil, and during the summer months are frequently found around diseased 

 maples and elms, sometimes with the ovipositor bent at right angles to the 

 body as the female is inserting it for the purpose of laying eggs. This insect can 

 hardly be regarded as very injurious since its operations are, confined largely to 

 unhealthy trees. 



There is also another insect commonly found around trees badly infested with the 

 pigeon Tremex, drawn there by the presence of its prey, the larva of the pigeon 

 Tremex. The lunate long sting, Thalessa lunator Fabr., is a slender, brown and 

 yellow insect about one and one half inches long and with a delicate "tail" or 



