358 MEDICAL ENTOMOLOGY 



structure of its proboscis, that it belongs to the genus Philaeniatoinyia 



(see page 48). Brunetti states that Dr. Annandale has seen this fly 



distended with blood while feeding on cattle, but this 



Bionomics and early i s no proof that it can obtain blood independently ; 



stages of Philae- it ig te common to mi( j M usca hattoni and Mnsca 



matomyia Imeata . f 



and insignis gwsoni distended with tresh blood. L meat a lays its 



eggs, about thirty in number and of the muscid type, 

 all together in cow dung ; the larvae hatch in about ten hours and are 

 mature in three days. The larva measures about 9 mm. in length and 

 is of a lemon yellow colour. The piipariitin is of a dark mahog- 

 any tint. 



Philaeniatoinyia insignis may be seen burying its proboscis between the 

 hairs on almost any part of the body of a cow, and the male sucks blood 

 as voraciously as the female. Although blood is its main if not its only 

 food both sexes have been seen applying their proboscides on the surface 

 of fresh cow dung, in a manner which suggests that they suck up 

 juice from the surface. Very occasionally the female has been seen to 

 alight on human beings and dogs and to attempt to suck blood. 

 When feeding the fly lies closely pressed against the skin of the host, its 

 body being parallel with the surface. It remains in one position until 

 replete with blood, and is not easily disturbed ; it can, in fact, be easily 

 picked off with the fingers. Like most blood-suckers, it passes out a 

 clear watery fluid, and later unaltered blood, from the anus as the 

 abdomen distends. 



The female lays from forty to fifty or more eggs of a large si/ie, all in 

 one place, in isolated patches of freshly dropped cow dung rather than in 

 larger collections of dried dung. On alighting, the female crawls over 

 the surface until it finds a small crack or crevice ; the ovipositor, which is 

 similar to that of Musca, is now thrust into the dung, the abdomen being 

 depressed, and all the eggs are deposited in a heap, from -J to J of an 

 inch below the surface. The process takes from six to ten minutes. 

 When there are a large number of flies about, one often sees half a dozen 

 or more all depositing their eggs in the same spot, their ovipositors being 

 close to one another, while their heads are turned outwards. When the 

 flies have finished laying their eggs an irregular heap of several hundreds 

 will be found in the dung. On one occasion as many as thirty-six 

 females were seen laying their eggs in one spot, their appearance sug- 

 gesting a swarm of bees in miniature; five hundred and sixty eggs were 

 collected later. When a group of females are laying their eggs all to- 

 gether in this manner, any new arrival will at once join them rather than 



