1919 ENTOMOLOGICAL SOCIETY. 35 



same season, others do not do so until the following spring. They differ, too, 

 in other ways but in appearance the general colour scheme is so similar that it 

 is not surprising if the farmer fails to differentiate between one kind and another. 

 Even the most experienced are puzzled at times owing to the sudden increase of 

 a previously rare species, I had an example a few months ago when I received 

 a consignment from Alberta. The species involved looked very like an insect to 

 which my colleague Strickland had devoted such profitable attention a few years 

 ago, namely, the army cutworm, but the larvEe seemed too large for the time of 

 year, besides being considerably farther north than usual. However, the fact 

 remains that they were very numerous and that they give every promise of causing 

 injury next spring. 



-The last on my list is locusts. Probably all have read of the time in the 

 seventies when an old enemy, the Rocky Mountain locust {M. spretus), came in 

 millions and devoured all in sight. It was before my time but eye witnesses tell 

 me that not a leaf remained and that the insects suddenly commenced to drop 

 from a clear sky and were soon falling as a severe snowstorm does. The species 

 is not, however, a native of our prairies; consequently, while it may breed for a 

 season or two in millions, the time must come when the climate proves unsuitable 

 and so they perish. Unfortunately we have several native species almost as de- 

 structive. One of them the Lesser Migratory Locust (M. atlanis) has on more than 

 one occasion caused serious damage, while several others assisted materially in 

 the depredations. A few dry seasons are generally sufficient to increase them to 

 injurious numbers and even when the weather proves unsuitable close at hand 

 they readily fly from elsewhere, consequently an outbreak a hundred miles or more 

 away may easily lead to one close at hand. 



I need hardly add in conclusion that there are many other pests requiring 

 attention and we are never sure when others will appear. Army worms, aphids, 

 tree pests and those of live stock all provide their periodic outbreaks and thus 

 while our problems are seldom fruit ones, we have, nevertheless, much to keep 

 us occupied. 



THE EECOVEEY IN CANADA OF THE BROWN TAIL MOTH PARASITE 

 COMPSILURA CONCINNATA (DIPTERA, TACHINIDAE.) 



John D. Tothill and Leonard S. McLaine. Entomological FinANCH, Ottawa. 



With considerable truth Oliver Wendell Holmes remarks that all boarding 

 houses are the same boarding house. He means by this that there is a monotonous 

 sameness about all of them, and that to know one of them is to know all of them. 

 Until about a decade ago it was thought that tachinid flies resembled boarding 

 houses in the monotonous sameness of their activities and that to know one of them 

 was to know all of them. We were shaken out of this rather comfortable notion 

 chiefly through the work of Pantel in France and Townsend in the United States 

 who showed that these two-winged parasites exhibited among the different species 

 a highly diversified and interesting set of methods for attacking their victims 

 and gaining a livelihood. 



One of the species studied by these authors was Compsilura concinnata the 

 little fly that forms the subject of the present paper. As to its method of attack 

 it was found that instead of depositing a large egg upon the skin of the victim — the 

 method of the bourgeoisie among the tachinids — it placed a fully developed maggot 



