72 



MISC. PUBLICATION 6 3 1, U. S. DEPT. OF AGRICULTURE 



CHRYSOMYA PUTORIA (Wiedemann) 



Synonymy. — This species has been considered by Patton and others as a syno- 

 nym of C. albiceps and C. rufifacies, but this is an error. 



Recognition Characters, — Adult : This is a green species with broad black 

 bands at the incisures of the abdominal segments ; it may be recognized by the 

 characters given in the key. Length, about 8 mm. 



Geographical Distribution.— Ethiopian Region: Senegal (Dakar), French 

 Guinea, Sierra Leone, Liberia, Ivory Coast, Gold Coast, Nigeria, Anglo-Egyptian 

 Sudan, Ethiopia, Belgian Congo, Uganda, Kenya, Zanzibar, Mozambique, Nyasa- 

 land, Southern Rhodesia, Natal. 



Pathogenesis. — This species is primarily a scavenger. It has been 

 recorded in human wound and nasal myiasis, but these records may be 

 the result of misidentification. 



CHRYSOMYA BEZZIANA Villeneuve 



The Old World Screwworm 

 (Fig. 34) 



Synonym. — Pycnosoma bezzianum (Villeneuve). In the early literature this 



species was recorded as Chrysomya megaeephala (F.), so some of the literature 



on that species really refers to this one. 



Recognition Characters. — Adult: The head is black above, except on the 



frontalia, but orange on the face, cheeks, antennae, and palpi ; the thorax and 



abdomen are green to bluish 

 purple, with narrow black pos- 

 terior margins on the inter- 

 mediate abdominal segments. 

 In the female the front is almost 

 parallel-sided, and the sides of 

 the frontalia do not bulge in the 

 middle (fig. 28) ; in the male 

 the facets of the eyes are rather 

 uniform, there being no definite 

 upper zone of larger facets and 

 lower zone of smaller ones (fig. 

 30). The stigmatal bristle is 

 well developed ; the mesotho- 

 racic spiracle is brownish, and 

 the squamae are waxy white. 

 Length 8-12 mm. Larva (fig. 

 35) : The mature larva is a 

 creamy-yellow maggot, 14-18 

 mm. in length and with only the 

 usual protuberances ; the mouth 

 hooks are strong; the spines in 

 the belts along the incisures are 

 strong, being visible to the 

 naked eye, and recurved, and 

 there are several irregular rows 



to each belt. The anterior spiracle terminates in 4 or 5 fingerlike processes. 

 Geographical Distribution. — Oriental Region : India, Ceylon, Burma, Thailand, 



French Indo-China, Philippine Islands. Ethiopian Region : Gambia, French 



Guinea, Ivory Coast, Belgian Congo, "Uganda, Kenya, Zanzibar, Northern Rhodesia, 



Southern Rhodesia, Natal (Zululand). 



Biology and Pathogenesis. — The adults are rarely seen in nature. 

 The females occur in the vicinity of cattle and other mammals; the 

 males feed on the surface liquids of fresh cow dung, on honeydew, and 

 on flowers. The eggs are usually glued to dry skin, in one or more 

 batches, just inside the rim of a wound; they are sometimes deposited 

 on unbroken skin covering bruises or abscesses, or in places soiled by 



Figure 34. — Chrysomya bezzicuta, adult female. 



