184 INSECTS AND MAN 



head dull yellow, but clothed with fine white down. The 

 bristles covering head, thorax, and abdomen are black, 

 with very few upon the dorsal surface of the thorax. The 

 under surface of the fly is clothed with finer downy hairs, 

 which form a grey coat on the thorax and first segment of 

 the abdomen. The maggot, which, when full grown, is five- 

 eighths of an inch in length, is dull light brown to dirty 

 white ; the dorsal surface is the darker, on account of being 

 furnished with a number of minute black spines, arranged 

 in regular bands and patches; there are bands of spines 

 also on the ventral surface The whole larval skin is finely 

 shagreened ; the small head is armed with a pair of black 

 hook jaws. The spiracles or breathing pores are on the 

 eighth segment, and the whole maggot is covered with a 

 fringe of fleshy tubercles, hence the popular name of hairy 

 maggot. The pupa is dark brown or even almost black, 

 slightly flattened, and the larval tubercles, which are aborted, 

 form an irregular coat of blunt spines. Often these pupae 

 are found in the sheep's wool, but, as a rule, pupation takes 

 place in the ground in this species, as with other closely 

 related species. 



There is some hope that the hairy maggot fly may not 

 assume such formidable proportions as to get beyond con- 

 trol, for, quite recently, a minute, dull metallic green chalcid, 

 one-twelfth of an inch in length, has been found actively 

 engaged in parasitising the pupae of this fly. As this 

 chalcid is a native hymenopteron and has been found to 

 increase enormously under artificial conditions, there is 

 every reason to hope that the Australian entomologists 

 will be able to secure a sufficient supply of these useful 

 insects to keep the hairy maggot in check. 



The sheep ked (fig. 51), although frequently termed a 

 tick, has no relationship with the true ticks, and, what is 

 more, bears no resemblance to them. Although a fly, like 

 the green bottle, it is more truly parasitic, being wingless, 

 and provided with strong claws, which enable it to cling 



