74 THE REPORT OF THE No. 19 



ominous flash alarmed the men, and they took to their heels. They had gone but a short dis- 

 tance when there was a fearful explosion and they were struck down senseless. On their 

 recovery they told how the aftair had happened. 



The loss was — the building ; the dynamite, worth about $1,200 ; charges for broken glass, 

 $140 ; and a smashed canoe ; but 7io trace of the wasps' nest could be found. 



SOME INTERESTING HABITS OF LEPIDOPTEROUS LARVJE. 

 By Arthur Gibson, Ottawa.* 



The student of insects is continually being astonished and mystified by the wonderful 

 thin*^ which are ever occurring in the entomological division of the animal kingdom. No 

 matter what kind of insect study one may enter upon, nature never fails to present a varied, at 

 times incomprehensiole, series of interesting objects. In the lepidoptera there is no excep- 

 tion to the rule. While mysteries will continue to be, at the same time, owing to the rapidity 

 with which the science is now developing, many of the facts which are, as yet, unexplainable, 

 will dbubtless in the near future be expounded, and knowledge which we are now badly in 

 need of, be duly placed at our disposal. A study of the larvie of our butterflies and moths will 

 soon convince the student that there is much of interest as regards even the habits of fche 

 commonest species, many of which show remarkable traits. 



As the title given this paper covers a wide field it is only the writer's intention to mention, 

 in a general way, some of the interesting habits which have come under his notice. When 

 asked for a short paper it occurred to me that if I could put together a few facts concerning 

 the habits of some of these larvse, my endeavor might not be without interest. 



At the outset a short mention will be made of the feeding habits of these creatures. All 

 have doubtless seen some caterpillars feeding, and know that the particular habits of each 

 kind vary to a great extent, almost every species showing some peculiarity. While some 

 caterpillars are extremely restricted in their choice of food, only feeding on one or two plants, 

 others are quite indifferent and will eat almost anything, some species having been known to 

 eat up everything in sight. A good common example of the former class is the Monarch 

 Butterfly, Danais archippus, Fab., the larvae of which are known to feed only on Asdepias, 

 while in illustration of those which are general feeders, the Variegated Cutworm, Feridroma 

 saucia, Hbn., might be cited. During July and August, 1900, the caterpillars of this species 

 fairly swarmed in the Province of British Columbia and the States of Oregon and Washington, 

 devouring plants of all kinds and causing a loss to grown crops of $168,000 in British Columbia 

 alone, from which it has been estimated that a loss of $2,500,000 accrued in that year in the 

 United States and Canada. 



From an economic point of view an understanding of the feeding habits of larvae is im- 

 portant. It is well known that if the grower of any marketable crop desires to obtain the 

 fullest returns, a knowledge of his insect enemies will materially aid him, when his fruit trees, 

 cereals, etc., are attacked by any of these pests. While some caterpillars are general feeders, 

 most species, however, are particular in their choice of food In the event of a certain cater- 

 pillar occurring in large numbers upon any single kind of fruit tree, or crop, anxiety or loss and 

 unnecessary work may be prevented if it be known to the producer that the species only feeds 

 on the plants upon which it is first found, or those botanically related, and that it is not likely 

 to spread to adjoining crops. Of course there are instances of certain caterpillars doing 

 damage to plants upon which they were not previously known to feed, but such occurrences 

 are unusual. Cutworms, for instance, which are the caterpillars of the Agrotid moths, as a 



Re.ad before the Toronto Branch of the Entomological Society of Ontario. 



