-116- 



applied dry), followed in ascending order by D (unincubated horn fly 

 diet, finely ground, applied dry), A (standard sand fly diet, finely 

 ground, applied dry), B (standard sand fly diet incubated with liver 

 powder, finely ground, applied dry), and E (standard sand fly diet, 

 coarsely ground, applied moist). Development times under C and D were 

 not significantly different from each other but were 48 to 52% 

 shorter than under A and B, and 76 to 82% shorter than under E. There 

 were no significant differences in development times observed between 

 diets A and B; both produced shorter times than diet E. Figure 3-8 

 shows the development times of immature stages on each diet regimen. 

 On diets A, B, and E, the 4th stadium was longer than either of the 

 nonfeeding stages (egg and pupa). On diets C and D, the 4th stadium 

 was slightly shorter than either nonfeeding stage. Very little 

 difference was observed in duration of egg and pupal stages under 

 diets A through D. Unexpectedly, the durations of the nonfeeding egg 

 and pupal stages, as well as each feeding stage, were significantly 

 longer under diet E. Under this regimen, the 4th stadium exceeded 

 both nonfeeding stages and the pupal stage exceeded the egg stage. 

 Percent survival to the adult stage varied from 30% on diet E, to 94% 

 on diet D (Table 3-5). 



Diapause and quiescence . Most eggs in batches laid within a two- 

 day period hatched in five to ten days regardless of generation. In 

 at least 3% of the cultures, when the majority of larvae were in the 

 4th stadium, already pupae or adults, newly hatched lst-instar larvae 

 were also observed, at least 30 days after oviposition. Delayed hatch 

 in one laboratory culture was observed 113 days after oviposition. 

 This was usually, but not exclusively, observed under adverse culture 



