100 ENTOMOLOGICAL SOCIETY. 



called the house fly. This is the Musca domestica, a medium sized grayish fly too well 

 known to need description. 



The life history of this species, which is fairly typical of the majority of them, 

 may be briefly outlined as follows : It passes the winter in the house or some other 

 building, hiding in sheltered spots anywhere between the cellar and the garret. A 

 few specimens in the warmed rooms occasionally hum about in the winter, reminding 

 us that they have seen better days. In the early spring the few sole survivors of the 

 swarms of the preceeding year make their appearance. These are mostly females 

 ready at once to become mothers and by the end of the season their children and great 

 great grand children extend to the tenth and twelfth generations. Each female lays on 

 an average about 120 eggs at a time, which are deposited in irregular masses usually 

 in horse manure. The eggs hatch in about twenty-four hours and tbe larvae coming 

 from them are white footless maggots about half an inch in length. In this stage of 

 its existence the fly is beneficial as a scavenger. In from five to seven days the 

 larvse attain their full size, and enter the pupa or resting state. In its outward 

 appearance the pupa is a smooth brown oval shell about a quarter of an inch in length 

 and less than half of that in diameter. In manure heaps these may often be gathered by 

 the shovel-full. In some investigations conducted at Washington last summer, as many 

 as 1,200 larvse and puparia were counted in one pound of horse manure. The pupa stage 

 also lasts only from five to seven days. So that to produce a full fledged fly from the 

 laying of the egg requires only about ten days or two weeks. 



To trace the development of the fly through all of these stages is very easy, but to 

 ascertain the length of life of the adult fly is more difficult, and as yet I have seen no data 

 on the subject. The Washington experimenters declared that this was a bit of information 

 almost impossible to obtain correctly, because of the inability of the fly to live in close 

 confinement. Here then is a point in the life history of one of our commonest insects about 

 which we are yet more or less in the dark. 



A few of the other species of flies commonly found in houses may be mentioned- The 

 one most closely resembling the house fly in appearance is the Stomozys calcitrans, or 

 stable fly, so troublesome upon horses and cattle. The most important difference in this 

 species is that the mouth parts are formed for piercing the skin. A bite from one of these 

 is just as painful as the sting from a bee, but it has not the same poisonous after-effects. 



One of the largest species found in houses is the Calliphora vomitoria, or "blue-bottle 

 fly," that big, blue, buzzing, bummy, beggar that goes tearing through the house from room 

 to room as though he owned the premises. He is capable in a few minutes of arousing 

 more fight in a woman than all the other flies combined. A favorite place for this species 

 to lay its eggs, is in meat that has been exposed for a short time. As with most other flies, 

 the time required for development is short, and the rate of increase is so rapid that it has 

 given rise to the saying that a pair of these flies will devour an ox more rapidly than a lion, 



One of the smallest species seen in houses, the Homalomya canicularis, is sometimes 

 called the small house-fly. This species is largely responsible for the prevalent but erronous 

 idea that little flies become big ones. 



In closing this paper we should like to enter a plea for a more general study of this 

 most interesting branch of natural history. In none do we find a greater range for obser- 

 vation and research, and in none can practical investigation be turned to more profitable 

 account. 



NOTES OF THE SEASON OF 1898. 



By J. Alston Moffat, London, Ont. 



One of the most noticeable pecularities of the Entomological year about London, was 

 the scarcity of diurnals ; many of the more common fornn being to all appearance en- 

 tirely absent. There were some noticeable exceptions to the rule, Pieris rapae for inst- 

 ance. From the early part of May to the end of the month, it was in unusual abundance 

 for the spring brood. More like what one is accustomed to see in the autumn about cab- 



