THE MUSCIDJS. 



95 



MfSCA VOMITORIA. 



during the summer are only too familiar to housewives. The larvae of the common Fly reside ia 



excrements of all kinds, and consequently the insects abound especially where such substances are 



allowed to accumulate, as in the neighbourhood of stables, 



&c. The flesh-eating species are tolerably numerous, and 



most of them are viviparous, depositing living larvse, which 



are hatched in the oviducts, upon dead animal substances 



of all kinds. The ovarian organs are of large size, and the 



female of Sarcophaga carnaria may produce as many as 



20,000 young larvae, and thus one cannot be surprised at 



the influence these seemingly insignificant animals have 



in the removal of carrion. The Flesh Fly (Sarcophaga 



carnaria), one of the largest of our species, is about half 



an inch long, black, with six greyish-white streaks upon the 



thorax, and four rows of square white spots upon the 



abdomen. Under the term Bluebottle at least two species are included, namely, Mttsca vimitoria 



and M. erythrocephala. They both have the under surface of the head red, but in the former this 



part is clothed with reddish and in the latter with black hairs. There are also two abundant 



species of so-called Greenbottle Flies (Musca caisar and M. cornicina), remarkable for their 



beautiful golden-green or bluish-green colour, but distinguishable by the palpi being tawny in the 



former, black in the latter. There are many other species, and all have the same scavenger-like 



functions to perform in the economy of nature. Occasionally, however, these larvae become 



directly injurious to man, by getting introduced into the stomach with food, or by attacking sores 



and other open wounds. In the latter way they also frequently plague domestic and other 



animals. 



A fly closely resembling the common House Fly is the Stomoxys calcitraiis, which, however, is 

 furnished with a long, slender, projecting proboscis, by means of which it pierces the skin and sucks 

 the blood of man and other animals. A still more formidable species is the TSETSE FLY (Glossina 

 morsitans) of tropical Africa, of which such terrible accounts have been given to us by travellers in 

 those regions. The Tsetse, which inhabits certain parts of Central Africa, bites cattle so severely as 

 to injure them greatly, causing them to fall into a diseased state and finally die ; in fact, the action 



of this fly is said to be so pernicious as to render the zones 

 which it inhabits impassable barriers to man and domestic 

 cattle. 



An immense number of species of Muscidae have the 

 halteres uncovered, the wing scales being either absent or 

 greatly reduced in size. The group formed by them has in 

 consequence received the name of ACALYPTER.E. In other 

 respects they exhibit considerable differences both of structure 

 and habit. 



The larvae of a considerable number live in excrements, 

 and one of the most abundant of these is a dingy yellow-looking 

 fly, about a third of an inch long, which may be met with 

 during the greater part of the year, flying about and alighting 

 upon manure heaps in the fields and elsewhere. This insect 



is very appropriately denominated Scatopliaga stercoraria, both generic and specific name serving 

 to indicate the unsavoury nature of its haunts. Its eggs are deposited in dung, as moisture is 

 necessary for their development, but in order that the young larva may not be smothered on its 

 emergence from the egg, the latter is not wholly immersed, but is prevented from sinking by two 

 divergent horns springing from its upper end. The perfect insect preys on other Diptera. The 

 Anthomyice, which are exceedingly numerous, over 200 European species being recorded, are nearly 

 related to the preceding, and, like them, deposit their eggs in excrementitious matter. Except when 

 engaged in oviposition, however, the perfect flies generally frequent flowers, as, indeed, is expressed 

 in their generic name. They are common frequenters of our gardens. One of the most abundant 



TSETSE FLY. 



