REPORT OF THE SOCIETY 111 



outer surface of the bark they are readily taken. An inspection of the branches 

 of an infested red oak will convince one of the important role such birds play 

 in the scheme of natural control. Nuthatches, brown creepers, chickadees, 

 warblers and other birds likely destroy many of the eggs. Sometimes the larvae 

 wander over the bark; in this way they expose themselves to the attack of 

 enemies and many no doubt are destroyed. 



Parasites. — The only parasite observed was a dipteron which emerged 

 autumn 1922 from a two years old caterpillar taken from a log. Attention was 

 specially called to this larva on account of an abnormal black scar which it 

 was carrying on the dorsum of the thorax. The larva was confined in a tin and 

 died. Shortly afterwards a small gray puparium was found adhering to the 

 tin, close by the withered remains of the host. The specimen was submitted 

 for identifications but on account of its poor condition it could not be deter- 

 mined. 



Associated Insects — Ants are often found in and around the tunnels. The 

 large carpenter species, Camponotus herculaneus Linn., gets into the heart of 

 the tree by means of the larval burrows and establishes large colonies in the 

 rotting wood, often honey-combing the entire centre of the tree. The carpenter 

 ants bear an interesting commensal relationship with their fellow-workers, the 

 carpenter borers, and while neighbourly do not in any way interfere with the 

 grubs at work, nearby ; most likely this is because the ants occupy the discarded 

 burrows and rotted areas, whereas the larvae work in the healthy sound wood. 



Injecting carbon bisulphide into infected tunnels will drive the ants out 

 but care should be taken to see that all the holes are plugged before hand, 

 otherwise the fumes will escape and the larvae be left unharmed. Early in 

 June, 1919, one of the trees under observation was badly attacked by borers 

 and ants. There were several large holes at the base through which the ants 

 were working. As soon as the chemical was injected the ants left hurriedly 

 The holes were all plugged, as it was thought at the time, and about two weeks 

 afterwards the trees was cut down. The entire centre was skeletonized into 

 a labyrinth of tunnels. There was no sign of the ants, but the larvae and 

 pupae remained apparently unaffected. An examination showed a number of 

 small holes which had not been stopped, and hence the fumes had escaped, 

 with the above results. 



Other arthropods besides ants were found in the tunnels near the entrances, 

 at various times. There were two or three species of centipedes; several spe- 

 cies of millipedes; small arachnids, snails, mites, woodlice, and sow-bugs 

 Most of these were attracted, likely by the sapflow, or sought some form of 

 protection within the tunnel's month. Apart from making the observation 

 and securing specimens, nothing worthy ol note was recorded of these. 



TROPISMS 

 Mechanical contact. 



The larvae are extremely sensitive to touch and will respond immediately 

 to the slightest stimulus, drawing themselves up nervously in jerky movements 

 if interferred with in the least way. Should any of the long erect, hairs on 

 the body be touched or rubbed the larva will assume a defensive attitude 

 rearing itself at once on the prolegs and completely bending back from the first 

 or second abdominal segments so as to bring the head over resting upon the 

 hind part of the body, in this position it will strike back savagely at its aggres- 



