Oestrides, or Bot-flies 
US 
Rhincestrus nasalis, the Russian gad-fly, parasitizes the naso¬ 
pharyngeal region of the horse. According to Portschinsky, it not 
infrequently attacks man 
and then, in all the known 
cases deposits its larvae 
in the eye, only. This 
is generally done while 
the person is quiet, but 
not during sleep. The 
fly strikes without stop¬ 
ping and deposits its larva 
instantaneously. Imme¬ 
diately after, the victim 
experiences lancinating 
pains which without in¬ 
termission increase in 
violence. There is an in¬ 
tense conjunctivitis and 
81. 
Larvae of Dermatobia cyaniventris. 
chard. 
After Blan- 
if the larvae are not removed promptly the envelopes 
ot the eye are gradually destroyed and the organ 
lost. 
Dermatobia cyaniventris —This fly (fig. 83) is widely 
■distributed throughout tropical America, and in its 
larval stage is well known as a parasite of man. The 
larvae (figs. 81 and 82) which are known as the “ver 
macaque,” “torcel,” “ver moyocuil” or by several other 
local names, enter the skin and give rise to a boil-like 
swelling, open at the top, and comparable with the swell¬ 
ing produced by the warble fly larvae, in cattle. They 
cause itching and occasional excruciating pain. When 
mature, nearly an inch in length, they voluntarily 
leave their host, drop to the ground and complete their 
development. The adult female is about 12 mm. in 
length. The face is yellow, the frons black with a 
grayish bloom; antennae yellow, the third segment 
four times as long as the second, the arista pectinate. 
The thorax is bluish black with grayish bloom; the 
abdomen depressed, brilliant metallescent blue with 
violet tinge. The legs are yellowish, the squamae and 
wings brownish. 
82. Young larva of 
Dermatobia cy¬ 
aniventris. 
After Surcouf. 
