The performance of two laboratory colonies of Glossina pallidipes Austen originating from two areas in Kenya, Nkruman in the Rift Valley and Mwalewa forest in the coastal area, are described and compared. Two attempts to rear flies from Nkruman failed. Flies from Mwalewa were maintained with variable success for four years. Difficulties in rearing flies from Mwalewa could be explained by irregularities in the conditions of the breeding room, in contrast to failures in rearing flies from Nkruman. Life budgets were made to evaluate the performances of the colonies. In both Nkruman colonies the highest mortality factor was ‘loss due to non-production’. In the Mwalewa colony the highest mortality was ‘loss due to low production’. The key mortality factors were ‘loss due to low production’ (Nkruman colony A), and ‘premating mortality’ (Nkruman colony B, and Mwalewa colony). Factors which possibly contribute to the difficulties in rearing G. pallidipes are discussed. Flies from Nkruman and Mwalewa differed from each other in copulation time, pupal weight, age at which the first larva is produced, and duration of interlarval periods. The results of this study support the assumption of the existance of population diversity in this species.
(Received April 03 1980)
(Revised May 29 1980)
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