472 OTHER BLOOD-SUCKING FLIES 



Phlebotomus minutus is a buff-colored sandfly. It is small, even 

 for a Phlebotomus; the female measures only about -^ of an inch 

 in length and the male considerably less than this. 



Other diseases with which Phlebotomus has been connected 

 are two which occur together in certain regions of the Peruvian 

 Andes, namely, Oroya fever and verruga peruviana (see Chap. 

 X, p. 178). These diseases, as pointed out elsewhere, have 

 long been confused, and even yet are held by some investigators 

 to be different phases of the same disease. Townsend, of the 

 U. S. Department of Agriculture, spent two years in Peru in- 

 vestigating the diseases (which he considers identical) and came 

 to the conclusion that Phlebotomus verrucarum is the transmitter, 

 basing his conclusions on the distribution and habits of the in- 

 sect, and on certain experiments which he undertook. The sand- 

 fly in question, which was discovered and named by Townsend, 

 is the only nocturnal insect which is closely limited in its dis- 

 tribution to approximately the same localities as is Oroya fever 

 and verruga, and it seems to be well established that the disease 

 is contracted at night. Townsend believes that he obtained proof 

 of the transmission of verruga, and obtained a typical breaking 

 out, by injecting into a dog the macerated bodies of insects which 

 had fed on a verruga patient, but his results have not been widely 

 accepted. If, as is now more generally believed, Oroya fever and 

 verruga are really distinct, then it is possible that P. verrucarum 

 may be the carrier of both diseases, or of either one or the other. 

 If this insect acts as a carrier for both diseases, which would be 

 a very unusual situation, this fact would explain the close limi- 

 tation of the two diseases to nearly the same zones, and would 

 also explain the frequency with which the two infections occur 

 simultaneously or following each other. That oroya fever is an 

 insect-borne disease is almost certain, and it is quite likely that 

 the sandfly discovered by Townsend will be found to be the 

 carrier of it. Verruga, however, is a smallpox-like disease and 

 may be contagious rather than infective. 



Phlebotomus verrucarum is a species of sandfly which breeds 

 principally in the damp recesses of the loose rubble fences which 

 are so universally used in Peru, and probably feeds largely on a 

 species of lizard, Tropidurus peruvianus, which inhabits the same 

 rock fences. According to Townsend it requires for its life cycle 

 a fairly high total of summer heat and jnuch moisture, with an 



