136 DESTRUCTIVE INSECTS OF VICTORIA: 



more trouble is needed to keep them in place. 

 When full fed, which in England is about ten months, 

 they loosen their hold and pass along the intestines, 

 and are discharged by the animal chiefly during the 

 summer season in Victoria from November to April. 

 Then they bury themselves in the horse-dung, and in a 

 space of from twenty-four to fourty-eight hours turn to 

 chrysalids, forming outside of the maggot, and much 

 resembling it in general appearance ; in color, after 

 the first twenty-four or forty-eight hours, of a light 

 brown, changing to dark brown, almost black. From 

 these chrysalids the fly comes out, after about four or 

 five to seven weeks in summer (England). 



Mr. Froggatt also gives, in the New South Wales 

 Agricultural Gazette, a very interesting account of the 

 Bot Fly and its doings in New South Wales. In 

 Victoria the Bot Fly is a comparatively recent pest that 

 is, in the olden days of the colony little or nothing was 

 heard of it. Now we are confronted with the fact that 

 the Bot Fly is becoming by far too frequent an occurrence, 

 and it is remarkable with what dread this pest is regarded 

 by horses generally. One singular fact is, that a horse 

 may be surrounded by swarms of u blow flies," but does 

 not appear to take any notice of them, but, let even a 

 single perfect specimen of the Bot Fly come near, the 

 horse seems to know instantly what it has to fear from 

 the presence of the u fly." 



With regard to the egg-laying, I have frequently seen 

 the eggs deposited on the manes of horses, sometimes 

 without the animal being aware of the eggs having 

 been deposited ; so there need be no discomfort, but 

 simply terror of the fly in question. 



Mr. Froggatt mentions that he had examined some 

 Bot Flies, in the National Museum collections, 

 Melbourne, and that these specimens were named 

 G. salutaris, and were identical with one sent to Mr. 

 Froggatt from Wagga, New South Wales. Walker 

 describes four specimens as found in England, and Mr. 



