362 



DISEASES OF UNCERTAIN ETIOLOGY 



THE PARASITE. 



Family : Psxchcjdidas. 

 Sub-famih' : Phlebotominae. 



An owl midge, P/ilebo/oiiius sp. Greatly enlarged. 

 (From Giles's " Gnats or Mosquitoes." 



Genus : Phlebotomus. 

 Species : P. papatasii. 



Characters. 



Small wings, hairy, second long vein twice forked. Legs long, 

 slender, densely covered with scales. Abdomen of ten segments, the 

 last carrying the genitalia. The oesophagus divides into two, one to 

 the sucking tube, the other to the mid-gut. 



Life-History. 



The female after fertilization sucks blood, lays 30 to 80 eggs, singly, 

 in damp places such as fissures in stones and bricks. They hatch in 

 four to six days in warm, twelve to fourteen days in cold weather. 



The larvse have no eyes, well developed mouth parts, body of twelve 

 segments, spiracles on the first and penultimate segments. 



Two very long bristles on two tubercles on the ultimate segment. 



This is characteristic. These are as long as the body. Larval 

 stage lasts two to fourteen days. Pup^e motionless, wrinkled brown 

 skin on the last three segments which fixes it to stones in dark crevices. 



The pupal stage lasts eight to twenty-eight days. 



The whole time required is from one tO' two months. 



Habits. 



Nocturnal, attracted by light. During the day it is found in shady 

 places, latrines, under stones, &c. The female only bites. 



The fly passes through the ordif.ary mosquito net. 



Spider webs are useless as they do not catch them. 



The bite is shar^'5, it leaves a rose red papule set in a reddish macula. 

 It itches for days. 



Sunlight drives the fly away. It is not a house-fly. 



