Entomology Unit
Fruit flies
Provision of Genetic Sexing Strains for SIT Programmes
The SIT requires that only male insects need to be sterilized and released and operational programmes can greatly benefit if strains can be produced which accomplish this in an effective manner. For Mediterranean fruit fly, these strains have been shown to be 3-4 times more effective in the field than conventional strains.
The Unit has been successful in producing a series of improved genetic sexing strains for the Mediterranean fruit fly. The current strain, VIENNA 8 MIX 2001, which is now being supplied to many operational SIT programmes, has increased stability and productivity over previous strains. It carries two markers, white pupae and temperature sensitive lethal and an inversion D53. The strain is now under production in five facilities. The parent strains needed to construct the genetic sexing strain, (T(Y,5)101 and Inversion D53, are continually maintained and as required they are used to regenerate a strain for shipment to an SIT facility. Emphasis will now be shifted to developing the sexing technology for other fruit fly species.
Genetic sexing strains for oriental fruit fly and melon fly have now been produced at ARS laboratories in Hawaii and they are based on the use of a white pupae mutant. In collaboration with the group in Hawaii, the strains will be transferred to the Unit where quality control and mating compatibility testing will be carried out. There are SIT programmes being carried for these species of fruit flies and if suitable the sexing strains would be a valuable addition to the SIT technology.