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Results 



Infection of Sand Flies and Parasite Development 



Leishmania mexicana (strain WR-411, Uvalde, Texas). Four hundred 

 sixty (87.9%) of 523 Lu. diabol ica and 145 (94.8%) of 153 Lu. shannoni 

 became infected when fed on histiocytomas of hamsters infected with L 

 mexicana (Table 4-1). Thirty-one (5.9%) of the L_u. diabol ica and 18 

 (11.8%) of the _Lu. shannoni females took visible second blood meals 

 from uninfected hamsters. First feedings by Lu_. diabol ica on 

 histiocytomas of the ear averaged 11 min, 22 sec (range = 6 min, 1 sec 

 to 14 min, 30 sec; n = 20), while second feedings on ears of 

 uninfected hamsters averaged only 5 min, 24 sec (range = 2 min, 30 sec 

 to 10 min 58 sec; n = 18). Infected females of both species were less 

 prone to feed to repletion at the second blood meal than uninfected 

 flies. Nonetheless, many took full blood meals. A few had difficulty 

 inserting their mouthparts and probed many times until they either 

 succeeded or gave up. The average time between first and second blood 

 meals was 7.0 and 7.5 days for L_u. diabol ica and Lu. shannoni , 

 respectively, and ranged from 3 to 14 and 5 to 13 days. Of the Lu . 

 diabol ica females, 40 (7.6%) died within one to three days after the 

 first blood meal from a ruptured peritrophic sac (Endris, 1982) and 

 ruptured midgut epithelium. The corresponding figure for Lu. shannoni 

 was 6 (3.9%). Such deaths were invariably accompanied by heavy 

 bacterial infections and were characterized by perfusion of the blood 

 meal throughout all parts of the body, including thorax, legs, and 

 antennae. Feedings on bacterial ly contaminated lesions seemed to 

 produce a higher mortality due to peritrophic sac rupture. 



