THE YOUNG NATURALIST. 



HeduvillS personatllS, (the wheel-bug) is common in outhouses, the 

 larva and pupa conceal themselves under dust, which they carry about on 

 their backs, the odour of this insect is very disagreeable. 



Musca TOmitaria. The blue-bottle or blow-fly belongs to the order of 

 Diptera, or two-winged flies. Its proboscis is retractile, which it can pro- 

 trude at pleasure, at the tip there are two large oval suckers or lips. The 

 mouth is adapted for extracting and transmitting fluid, it makes a loud hum- 

 ming noise when flying, by which it betrays itself as it enters our dwellings. 

 The female deposits her ova on meat, carrion, and in such species of Arnm 

 as emits a cadaverous odour. All the species of this genus are scavengers. 

 Nature has specially adapted them for the purpose of removing all putrid 

 matter from the surface of the earth. The larva feed in meat, carrion, &c. 

 It is the well known maggot or bait of the angler. 



Musca domestic a. The common house-fly is one of nature's scaven- 

 gers, the larva feed in decaying animal and vegetable matter. Since our 

 cesspools in Manchester has been emptied, and the putrid matter removed 

 once a week, these insects are not so abundant as they were previously, when 

 it remained for months ; that allowed them time to pass their transformations 

 and make their way into the houses, where they are very troublesome. I 

 have some suspicion that they are the means of conveying the germs of 

 disease. I accidently knocked the skin off one of my knuckles, which, as 

 as usual, I took no notice of, shortly afterwards I fell asleep and was awoke 

 by a fly which had settled on the wound, and had probably conveyed the 

 virus of disease from putrid matter, it was many months before it healed. 



Piophila Casei (the cheese fly). The larva feed in the cheese. Whether 

 to look on this insect as destructive or beneficial is a matter of opinion, how- 

 ever, as some people consider it to be the richness of the cheese which pro- 

 duce maggots, they are welcome to my share. Farmers generally exclude 

 this insect as far as possible from the cheese room, the cheese factors object- 

 ing to buy living cheese, except at a very low rate, and when the cheese 

 arrives in the warehouse, they endeavour to persuade their customers it is 

 the richness of it which has brought it to life. This insect deposits its ova 

 in cheese, where the larva feed. 



Piophila atrata (?), the bacon fly. The female deposites her ova in 

 bacon, hams, &c. There larva feed in the interior, and when full-fed drop 

 out and assume the pupa state, in the earth, or in the crevices of the floor, 

 where they undergo their transformation. 



(To be continued.) 



