-223- 



The hamster to hamster transmissions of L mexicana reported here 

 are the first ever by bites of anthropophil ic sand flies indigenous to 

 the USA. Endris _et aj_. (1984) demonstrated transmission of L 

 mexicana by Lu_. anthophora (Addis), a species sympatric with Lu . 

 diabolica in south central Texas. Although Lu_. anthophora has bitten 

 humans in the laboratory, this sand fly is not naturally 

 anthropophi 1 ic. The successful transmission of trials with Lu . 

 diabolica add substantially to the body of evidence incriminating this 

 species as the major potential vector, if not the only vector, of 

 autochthonous human leishmaniasis in south central Texas. 



There are differing opinions as to what constitutes incrimination 

 of a vector. On occasion, a species has been incriminated simply 

 because it is more abundant than others; sometimes it is because the 

 sand fly is a known vector in other foci; or the sole evidence may be 

 that wild-caught specimens were found to be naturally infected 

 (Killick-Kendrick and Ward, 1981). None of these observations alone is 

 enough to incriminate a vector beyond doubt. Killick-Kendrick and 

 Ward (1981) outlined five criteria that must be fulfilled before a 

 suspicion that a sand fly is a vector of human leishmaniasis becomes a 

 reasonable certainty. These are 



1. The species must be anthropophil ic and present in a place 

 where man becomes infected. 



2. The distribution of the suspected vector should accord with 

 the distribution of the disease in man, and the sand fly should be 

 sufficiently abundant to assume that it could maintain the 

 transmission of the parasite in nature. 



