INSECTS INJUKIOUS TO MAN AND STOCK IN ZANZIBAR. 399 



MUSCIDAE. 



Stomoxys calcitrans, L. Occurs everywhere in the island where cattle are found. 

 Larvae have been found in recent moist droppings ; manure pits swarm at all times 

 of the year with larvae and pupae. Animals somewhat out of condition are especially 

 singled out for attack, and this is a useful diagnostic sign when looking over a herd 

 for a suspected trypanosome case. The following non-biting Muscids have been 

 noticed feeding in association with S. calcitrans, licking the droplet of blood left from 

 the Stomoxys puncture : — Musca domestica, Pycnosoma putorium, and Biomyia 

 tempestatutn. 



Stomoxys nigra, Macq. Not so conunon as the preceding species, .but recorded 

 from numerous localities in both islands. 



Lyperosia minuta, Bezzi. These small flies are somewhat local in their distribu- 

 tion, showing a marked preference for open windy steppe country ; conditions not 

 favoured by other blood-sucking flies. 



Cordylobia anthropopharga, Grlinb. The only fly known to cause cutaneous myiasis 

 in man in Zanzibar. Several larvae have been obtained from human beings, others 

 from dogs, rabbits, and guinea-pigs. The pupal stage averages about 19 days. 



Musca dotnestica, L. Found in houses and around rubbish heaps throughout 

 the year, though Zanzibar town is remarkably free from these filth feeders. Their 

 favourite breeding grounds are manure pits containing fermenting horse and donkey 

 dung ; I have seldom found larvae in cattle manure. 



Lucilia sericata, Mg. A few specimens taken on meat in the public market. 



Pycnosoma putorium, Wied. Abounds at all seasons of the year in the public 

 markets, being especially attracted to fish stalls and less prevalent on meat. Larvae 

 are found in garbage containing decomposing meat and fish. I have noticed them 

 only occasionally feeding on human ordure. 



Pycnosoma marginak, Wied. Not so numerous as P. putorium. but commoner 

 on the meat stalls. Breeds in decomposing carcasses and meat. 



Pycnosoma hezzianum, Villeneuve. Larvae have been taken on several occasions 

 from donkeys' ears and from sores. In all such cases much destruction of superficial 

 tissue had taken place, associated with pus formation. 



Sarcophaga sp. Numbers are always to be found around cess-pits and privies. 

 Larvae abound in rotting meat and carcasses ; chicken entrails are generally thrown 

 away carelessly, and if not picked up by crows or cats become a potential breeding 

 nidus for various species of Sarcophaga. 



Synthesiomyia brasiliana, Br. & B. Large numbers have been bred from decom- 

 posing rats' carcasses. 



Oestridae. 



Oestrus ovis, L. Large nmnbers of larvae have been taken from the frontal sinuses 

 of goats ; in some cases they had penetrated to the base of the horn, but they do 

 not seem to cause any appreciable damage to their hosts. The pupal stage averages 

 10 days. Very common throughout the island. 



GastropUlm asininus, Br. A few adults have been taken flying around cattle 

 and donkeys. 



(C357) O 



