INSECT ENEMIES OF LIVE STOCK 185 



to the wool of its host. Of a general rust-brown colour, 

 with a grey-brown, irregularly spotted abdomen, showing 

 no distinct segmentation, and thickly covered with hair, 

 these insects present a strikingly curious appearance. The 

 female is about five millimetres in length, and the male 

 is smaller, rarely exceeding three millimetres. The life- 

 history of the ked is remarkable in many ways, not the 

 least curious fact being that it spends every stage, larva, 

 pupa, and adult, on the host. The female gives birth to 

 four or five creamy, ovoid, shining, slightly flattened grubs ; 

 no egg is laid, hatching and full larval development takes 

 place in the body of the mother fly. The larvae are fixed 

 to the wool of their host, and almost immediately transform 

 into oval, glistening, copper-coloured pupse, which rapidly 

 turn almost black and resemble apple pips, though the 

 resemblance is often masked by a sticky white incrustation 

 by which they are fixed to the wool. Keds are provided 

 with sucking mouths which enable them to absorb blood 

 from their host; it is also supposed that they obtain a 

 considerable amount of nutriment from the grease with 

 which sheep's wool is always richly charged. Although 

 these parasites cause considerable annoyance to sheep 

 and goats, when present in large numbers, it is only to 

 lambs that they are likely to cause death. 



Several other flies of the family Hippoboscidce, to which 

 the ked belongs, are parasitic on domestic animals. On 

 the horse is Hippobosca equina, and, in Brazil, Hippobosca 

 nigra ; the former also attacks the ass, mule, dog, cattle, and 

 swine ; its varied hosts are probably accounted for by the 

 fact that, unlike the ked, it is winged and is, accordingly, 

 not so strictly parasitic in habit. The camel, in Egypt, 

 has a dipterous parasite in the shape of Hippobosca came- 

 lina, whilst Hippobosca rufipes, Hippobosca maculata, and 

 Hippobosca taurina are parasitic on cattle. Maculata, 

 though a native of India, was introduced into South Africa 

 during the Boer War, where mfipes is common; both of 



