INVITRO FEEDING IN REARING OF TSETSE FLIES (GLOSSINA-M AND GP PALPALIS, DIPTERA-GLOSSINIDAE)

Abstract

The increasing demand for laboratory reared tsetse flies for research and biological control makes it necessary to develop effective and standardized tsetse fly feeding methods without using live animals for the daily blood intake. The in vitro feeding technique, described was used for rearing G. m. morsitans by feeding them defibrinated equine blood through a silicone membrane. Results obtained for female longevity and productivity and mean weight of puparia were satisfactory. Feeding defibrinated bovine blood resulted in significantly lighter puparia. A colony of G. p. palpalis feeding on defibrinated bovine blood was the only colony of this species successfully maintained by in vitro feeding over several years. The survival rate of females fed defibrinated bovine, equine or porcine blood was equal. The number of larvae produced by females being fed defibrinated equine blood was significantly lower. Females < 50 days old produce larvae which formed heavier puparia than females aged between 51-80 or 100 days, irrespective of blood source. Bovine blood used within the first 3 days after its collection led to significantly higher mean weights of puparia than bovine blood used thereafter. The increasing degree of hemolysis was most probably not the reason for this observation. A colony production model based on the performance of both species, G. m. moristans and G. p. palpalis, fed in vitro, showed the importance of the first 5 age group periods (i.e., 45-50 days after emergence) for overall performance. About 2.3 purparia/female were needed to maintain the same number of females in the colony. This level of production was reached in the 5th age group period. All larvae produced thereafter were available for colony expansion or experimental purposes.