54 THE REPORT OF THE No. 36 



first nest of Lasius into its entrance, the Myrmicae apparently did not know what 

 to do. A few put up a weak fight and in a few moments all retreated, leaving the 

 Lasii in possession of their insects right at the Myrmica entrance. There were 

 plenty of Myrmica workers out to drive off the Lasii, for there were not nearly 

 as many of the second nest out as there had been of the first. Does this indicate 

 that the Myrmicae fight in a more or less regular formation, and being surprised 

 . when this formation was broken up, they retreated rather than fight ? 



Another thing: On the night of August 18-19th, when the Myrmicae were 

 first disturbed they brought all of their young to the surface with them. From 

 having seen dozens of Myrmica migrations, we can say positively that they were 

 fully prepared to migrate. On the second night we find only a few young brought 

 to the surface and immediately returned, showing them to be less excited over the 

 presence of Lasius than on the previous night. On the third, fourth and fifth 

 nights no young were brought to the surface at all. It was fear that induced them 

 to bring their young to the surface the first night; on the second night we find 

 that fear greatly abated, as fewer young were brought to the surface and kept 

 there for a much shorter time. On the third, fourth and fifth nights we find no 

 young brought to the surface; so, evidently, they had no fear of their nest being 

 raided by Lasius. Can we conclude that this nest of Myrmica was profiting by ex- 

 perience? It certainly was showing a degree less of alarm over the appearance of 

 Lasius after each successive conflict. 



Again, on the first night of the battle, the Myrmicae stood about the entrance 

 of the Lasius nest for 20 minutes after the last Lasius had disappeared. Whether 

 they were simply wondering where they had gone, or, whether they expected them 

 back, and so were picketing the entrance to prevent their reappearance, we cannot 

 say. On the second night we find them waiting about this entrance for less than 

 15 minutes. On the third night we find them waiting less than two minutes, and 

 on the fourth night, scarcely waiting to drive the last Lasius in. Does this indi- 

 cate that they slowly proved to themselves the futility of waiting; that they re- 

 membered their earlier experiences, and so did not wait at all on the night of the 

 22-33rd ? 



The notes on these conflicts were taken at the same time, separately by Mr. 

 Flint and myself, and later compared. The notes on the behaviour of Myrmicae, 

 when in ordinary conflicts with the Lasius, are from hundreds of observations, and 

 go to show the cunning of the Myrmica in battle. 



The questions which I am not attempting to answer, are those which sug- 

 gested themselves to Mr. Flint and myself when taking the notes. 



THE SPRUCE BUD-WORM, TORTRIX FUMIFERANA, CLEMENS. 



By Arthur Gibson, Chief Assistant Entomologist, Experimental Farm, 



Ottawa. 



During the early part of the past summer the Spruce Bud-worm was especially 

 abundant in Canada. Towards the end of July the Deputy Minister of the 

 Department of Agriculture was informed by the Hon. Senator Edwards that some 

 kind of an insect was doing much damage to spruce and balsam trees in the 

 above district, and as a consequence I was instructed to proceed at once to the 

 infested locality, to investigate the outbreak. 



