-227- 



developed from a modified horn fly diet, reduced the average time from 

 egg hatch to adult emergence by about 50%. Quiescence and diapause 

 were observed in both the egg and larval stages, with hibernation of 

 up to 270 days in the egg stage of outdoor-reared sand flies. 



5. Vector capacities of Lu. diabol ica and Lu. shannoni for L 

 mexicana (strain WR-411) were investigated under controlled laboratory 

 conditions. Eighty-eight percent and 95% infection rates were 

 obtained in _Lu. diabol ica and _Lu. shannoni , respectively, when flies 

 were fed on leishmanial histiocytomas of hamsters. For the first 

 time, transmissions of Leishmania mexicana to hamsters were obtained 

 by bites of infected Ljj. diabol ica and Lu_. shannoni females, six to 

 seven days after the infecting blood meals. 



6. Leishmania mexicana amastigotes from hamsters infected by 

 bites of Lu . diabol ica , and promastigotes from infected sand flies 

 were examined with an electron microscope. The number of 



subpel licular microtubules in promastigotes showed a wider range of 

 variation than is reflected in the literature. 



To complete the chain of evidence linking Lu. diabol ica with 

 transmission of human cutaneous leishmaniasis in south central Texas, 

 it is recommended that field surveys be continued to: 1) more 

 precisely delineate the geographic distribution of Lu. diabol ica and 

 to locate adult resting and larval breeding sites; 2) isolate 

 leishmanial parasites from wild-caught sand flies that are 

 indistinguishable from the parasites causing the disease in the same 

 place; and 3) determine the natural mammalian hosts of Lu . diabol ica 

 and potential reservoirs of Leishmania in endemic areas. 



