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hamster with histiocytomas due to L mexicana was placed inside a 

 colony chamber, only 10.4% of the females that fed became infected. 

 When the flies were restrained in 120 ml screen-lidded feeding 

 containers, and the screen pressed directly against a histiocytoma, 

 96.3% of those that fed became infected. This latter method was used 

 in the present study to obtain L mexicana infection rates of 87.9% 

 and 94.8% in Lu_. diabol ica and Lu. shannoni , respectively. This 

 insured that a large number of infected flies were available for 

 transmission studies. 



The time required by female sand flies to complete the infecting 

 blood meals on leishmanial histiocytomas averaged five minutes longer 

 than that observed for first, noninfective feedings on uninfected 

 hamsters. This may be due to restricted blood flow within the 

 histiocytoma. Infected flies feeding on ears of uninfected hamsters 

 fed to repletion in about the same time as uninfected flies. 



The death of a small percentage of infected flies from ruptured 

 peritrophic sacs was expected. This was also observed in uninfected, 

 laboratory-reared Lu . diabol ica . Endris (1982) reported mortalities 

 of 6.6 and 9.9% due to peritrophic sac rupture in three laboratory 

 generations of L_u. anthophora . He stated that in these flies, death 

 followed feeding within one to four days, with 75% dead within 24 hrs. 

 He hypothesized that death occurred as a result of changes in the 

 hemolymph osmoticum and release of digestive enzymes. Adler and 

 Theodor (1957) stated that the alimentary tract of fed and unfed sand 

 flies is bacteriological ly sterile and that chance bacterial 

 contamination interferes with digestion of the blood meal and is fatal 

 to the insect. Lu. diabol ica were probably contaminated with bacteria 



