290 OUR INSECT FRIENDS AND FOES 



crythrocephald) has, if anything, a worse character 

 than the House-fly, for it feeds to an even greater 

 extent upon putrid, decomposing animal matter, 

 and is also very fond of ripe fruit such as plums, 

 pears, cherries, grapes, figs, and dates displayed 

 for sale outside greengrocers' shops. It is obvious 

 that by crawling over fruit and other food-stuffs 

 this fly has the power to contaminate them with 

 the disease germs carried on its hairy body and 

 legs from some previous noisome repast, and 

 therefore it is most important during the summer 

 and early autumn at least, that all fruit purchased 

 from stalls or barrows should be most carefully 

 washed, and thoroughly cooked before being 

 used for food. The eggs of the Bluebottle Fly 

 are deposited upon raw and cooked meats, the 

 dead bodies of animals, birds, fishes, and, indeed, 

 most animal garbage. 



The Blow-fly, or Flesh-fly (Sarcophaga car- 

 naria), is a serious foe, not only as a carrier of 

 bacteria, but also on account of its larvae 

 attacking living sheep. In some districts, par- 

 ticularly the Fenland country, the shepherds have 

 to keep a sharp watch upon their flocks during 

 the summer and autumn to protect them from 

 the attacks of this pest. The maggots, if left 

 undisturbed, eat their way into the skin of 

 the sheep, causing the poor animals great 

 suffering, and if neglected, their death. The 

 fecundity of these flies is extraordinary, a single 

 female being capable of producing some fifteen 

 to twenty thousand larvae. The Stable-fly 

 (Stomoxys calcitrans) breeds in fermenting horse 

 manure and vegetable refuse, and, loading its 



