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Development . The overall mean durations of larval and pupal 

 development periods for all generations was 35.9 and 8.4 days 

 respectively (Table 3-3). Statistically significant decreases in 

 development times between generations were brought about by an 

 increase in rearing temperature (24°C to 27°C between the 3rd and 4th 

 generations) and by improvements in larval diet (13th generation). 



Mean development times for individual ly reared _Lu_. diabol ica were 

 significantly shorter for each immature life stage at 27°C than at 

 24°C (Table 3-2). Total immature development time was, on the average, 

 ten days shorter at the higher temperature than at the lower one. At 

 both temperatures, the order of immature stages from longest to 

 shortest duration was egg, 4th stadium, pupa, 1st stadium, 2nd stadium 

 and 3rd stadium. The 2nd and 3rd stadia were of nearly equal 

 duration. 



Survivorship curves for immatures reared at the two temperatures 

 are presented in Figure 3-6. Highest mortality occurred in the egg 

 stage (46% at 24 C; 44% at 27 C), followed by the 1st stadium (12% at 

 24 C; 10% at 27 C). Mortality beyond the 1st instar at both 

 temperatures was rather low. 



Table 3-4 and Figure 3-7 compare immature development times of F^ 

 males and females at 24°C and 27°C, respectively. Males developed two 

 days faster than females at 24°C and one day faster at 27°C. The 

 duration of the 4th stadium was significantly greater in females than 

 in males, at both temperatures (student's t (z) test, a = 0.01). 



Twelfth-generation larvae were reared individually at 27°C on 

 five larval diets (Table 3-5). The shortest development times were 

 observed under diet regimen C (incubated horn fly diet, finely ground, 



