THE FLIES THAT CAUSE MYIASIS IX MAX 83 



into the penultimate one ; the posterior spiracle (fig. 40. B ) is without a sclerotized 

 peritreme, and its slits are long and serpentine, at least one of them usually 

 being fragmented into two parts. 



Geographical Distribution. — Ethiopian Region: Niger, Senegal, Gold Coast, 

 Gameroons, Gabon, Middle Congo, Belgian Congo, Angola, Kenya. Southern 

 Rhodesia. 



Biology and Pathogenesis. — The adult fly inhabits wet tropical 

 forests and is crepuscular. It feeds on fruits, sweet juices, excrement, 

 etc.: it may live 6 weeks or more. Eggs are deposited on soil or in 

 places where the host is likely to rest. The number of eggs produced 

 by a female in her lifetime may exceed 500. The eggs hatch in 2 to 4 

 days, and the young larva then penetrates the integument of the host 

 while the latter is at rest. The larva finally comes to rest in a tumor 

 formed under the skin. There are the usual three larval instars. 

 The larval stage normally lasts about 12 to 15 days: the pupal stage, 

 which is passed in the soil, lasts 23 to 26 days. The normal hosts seem 

 to be African antelopes (C ephalophas) and rodents (Cricetomys) . 



Domestic animals seem not to be affected, and man is an abnormal 

 host, although occasionally he is infested. The tumors are similar to 

 those of Cordylobia anthropophagy though larger and more painful. 

 No great quantity of pus is formed. The duration of parasitism is the 

 12 to 15 days of the larval life of the parasite although it may pene- 

 trate the skin unnoticed, where its presence may not be detected for 2 

 or 3 days. 



Literature. — A detailed discussion of this species, with its biology, 

 pathogenesis, and descriptions of immature and adult stages, is given 

 by Rodhain and Bequaert (122) ; for a more recent study of the larva, 

 see Bertram [I4). 



The Genus LUCILIA Robineau-Desvoidy 



(including PHAEXICIA Robineau-Desvoidy) 



The Green-botrle Flies 



The species treated here have been referred to Lucilia by most au- 

 thors: but recently Hall (J^9) has followed Townsend in recognizing 

 several generic segregates. Though it is probable that the more re- 

 stricted generic treatment will ultimately be adopted, these two genera 

 are here treated together for the sake of convenience. 



The genus Lucilia, in the broader sense, includes a number of species 

 of metallic flies, usually green or bluish green, of medium size. The 

 following characters are common to the species of Lucilia and Phtu - 

 nicia treated here: The parafacials and parafrontals are largely cov- 

 ered with silvery or golden pollen, though the parafacials lack pile: 

 the eyes are bare; the arista is long-plumose almost to the apex. The 

 mesonotum is convex; the propleura and both squamae are bare. The 

 wings are hyaline: vein r 4+s is ciliated almost to cross vein r-m. The 

 abdomen lacks discal bristles except on the anal segment, and the mar- 

 ginal bristles on the intermediate segments are small and incon- 

 spicuous. 



Pathogenesis. — Most species of Lucilia and Phut nicia are saprophy- 

 tic. However, in P. sericata (Mg.) and P. cuprina (Wd.) the para- 

 sitic habit has developed to a serious extent, these species being im- 

 portant sheep maggots and occasionally attacking man. As parasites 



