PHLEBOTOMUS PLIES AS DISEASE CARRIERS 471 



crevices in damp cellars, in caves, cracks in broken walls, etc. In 

 Malta the life cycle of this species has been observed to take about 

 three months, but under ideal conditions it would probably be 

 shorter. 



The adult fly, as observed in Malta, where it has been most 

 extensively studied, chooses caves, catacombs and other similar 

 places as its favorite localities. On still, warm nights it is com- 

 mon in houses, but rarely appears when there is a cool fresh breeze. 

 Some houses were found to be much more infested than others, 

 possibly due to the proximity of suitable breeding places and to 

 the lack of breezes. Newstead found that dark rooms on the 

 sheltered side of the first floor of a house were most likely to be 

 infested; only one individual was found on the second floor. 

 The distance which the adults travel is thought to be very short, 

 but they may be carried by public conveyances, and infection 

 has been known to be transplanted long distances by flies carried 

 on coasting vessels. 



Phlebotomus and Other Diseases. — Sandflies have frequently 

 been suspected of complicity in the spread of the parasites of 

 oriental sore, though no definite proof of this has ever been 

 brought out. Wenyon, from his study of oriental sore at Bag- 

 dad, believed that these flies, as well as certain other insects, 

 might easilj' be concerned in the spread of the infection, but he 

 did not have an opportunity to test his belief. Recently a 

 number of French workers in North Africa, including Laveran 

 and the Sergents, have advanced the theory that P minutus 

 var. africanus is the carrier of the infection, and that certain 

 lizards or geckos of the region, Tarentola mauritanica, serve as a 

 reservoir for the disease. Parasites, closely resembling Leish- 

 man bodies which cause oriental sore, have been found in the 

 blood of geckos taken near Tunis, and it is well known that rep- 

 tiles are an important if not the prime source of food for the 

 various species of Phlebotomus, and P. minutus especially harasses 

 the North African gecko. Roubaud found a lizard in West 

 Africa which was covered with gorged females of this species 

 and in India P. minutus is said to prefer geckos to man as a 

 source of food. It is interesting to note in this connection that 

 the forest workers in Paraguay, where the more serious American 

 type of leishmaniasis is found, believe the infection to be caused 

 by the bite of blood-sucking arthropods which have fed on snakes. 



