246 INSECT ARTIZANS AND THEIR WORK 



got rid of the attentions of one class of pests to 

 fall under the care of another group. Even Mrs. 

 Troglodyte-Smith must have found that there were 

 undesirable creatures who insisted upon sharing 

 her cave. 



Some of these sanitary or scavenger flies, though 

 their habits in the larval stage are similar to those 

 of the Blow Fly, rarely or never enter our houses, 

 and therefore do not become a nuisance to us. 

 Such are the Green-bottle (Lucilia ccesar) and the 

 Flesh Fly (Sarcophaga carnaria). The first does 

 occasionally wander into open windows and doors 

 in the summer, but does not stay in the house, 

 preferring to sit on leaves in the hottest sunshine 

 and exhibit its shining golden-green livery to the 

 best advantage. 



The Green-bottle is the special bane of the 

 fishmonger, and if by chance we pass by the back 

 premises where this tradesman temporarily stores 

 his refuse, we shall startle up a cloud of these beauti- 

 ful but repulsive insects, who have been engaged 

 not only in depositing eggs in the offal, but in 

 sucking up the more fluid decomposing portions. 



The Flesh Fly is similar to the Blow Fly, but 

 rather longer and of a grey-and-black coloration 

 instead of the steely blue which has given the name 

 of Blue-bottle to Calliphora vomitoria. It is a 

 carrion feeder, but out-of-doors, and it retains its 

 eggs until they are hatched, so that on the dis- 

 covery of suitable material for their deposit the 

 sanitary work of clearing away dangerous matter 



