Before removal from the emergence cage, 12.8% of 141 newly emerged females
of Glossina austeni Newstead less than 24 h old were found on dissection to
have been inseminated. Likewise, dissection of a sample of sterilised fema
les destined for release showed that 5.43% of 2487 females had already been
inseminated while still in the emergence cages. It was decided therefore t
o put female and male flies together in production cages from the day of em
ergence at a ratio of 1 male to 5 females and leave them to mature and mate
in the cages. The females produced viable pupae of acceptable mean weight
and desired quality with the proportion of A-Class pupae less than 10%. The
number of pupae per initial female (PPIF) did not differ from pupae produc
ed by pre-aged parent flies. It is now clear that there is no need to age f
emale and male flies of G. austeni before mating. Parent flies of less than
1 day old put together in production cages from the day of emergence have
been used for mass rearing G. austeni in the Tsetse and Trypanosomosis Rese
arch Institute (TTRI) colony to produce males for the eradication programme
in Zanzibar since December 1995. This has substantially reduced the labour
of fly production by removing the need to age flies and the need to chill
and separate flies after mating. (C) 1999 Published by Elsevier Science B.V
. All rights reserved.