-125- 



the lower portion of Figure 3-12 shows the emergence pattern of adults 

 from 32 egg batches of the 13th generation. The immature stages were 

 reared at 27°C and fed unincubated horn fly diet, finely ground and 

 applied dry. Emergence times ranged from 26 to 52 days post 

 oviposition, with an average of 32 days, 13 days shorter than in the 

 1st generation and 30 days shorter than in the 6th. Males emerged an 

 average of 1.5 days earlier than females. Eighty-one percent of 

 adults emerging in the first five days were males and eighty percent 

 during the last 15 days were females. . 



The adult emergence patterns of colonies reared at 24°C and 27°C 

 on regular sand fly diet (coarsely ground and applied moist) are 

 presented in Figure 3-13. The time to adult emergence was ten days 

 shorter, and the range of emergence was 20 days shorter at 27°C than 

 at 24°C, producing a more synchronous pattern. Protandry, or the 

 average time that male eclosion preceded female eclosion, was reduced 

 an average of 3 days. 



Emergence patterns of adults reared on five larval diets are 

 compared in Figure 3-14. Diets C and D produced adults one week 

 earlier than diets A and B, and almost a month earlier than diet E. 



Sex ratios. The overall ratio of males to females (based on 100 

 females) for nine generations was 114:100 and ranged from 87:100 in 

 the 3rd generation to 427:100 in the 7th generation. The results of 

 larval diet experiments provide evidence that sex ratios may be 

 modified by nutrition. Male to female ratios were 128:100, 58:100, 

 103:100, 103:100, and 236:100 for diets A, B, C, D, and E, 

 respectively. Significantly fewer males were produced on diet regimen 

 B (standard sand fly diet with liver powder) than on the others, and 



