Storage time effect on blood diet for tsetse mass production in sterile insect technique

Different methods have been developed for tsetse and trypanosomiasis control or eradication but all these have their specific advantages and limitations. However, a combination of methods could be used as part of an Area-wide Integrated Pest Management (AWPM). The sterile insect technique (SIT) as a technique of choice for eradication of tsetse flies requires mass production of flies in the laboratories. Since tsetse's are exclusively haemotophogous insects, a quality blood diet is needed for maintenance of flies with optimum production. The aim of this study was to establish the optimum storage time of blood diet for tsetse colonies.

A total of 450 flies Glossina austeni were fed on different batches of blood (collected in 2004, 2005, 2006, 2007 and 2008) three times a week. Pupae were collected daily and mortality checks were done on weekly basis. The quality of the blood diet was measured by observation of tsetse production parameters including survival, pupae production and size.

The survival of flies fed on 2004 and 2006 batches had lower survival compared to the rest of the batches. Also the 2005 batch had a significant higher number of pupae compared to the production in other treatments. The 2004 and 2005 batches had more of small pupae (class A & B) compared to the other batches.

There was a significant difference between the blood batches and the production parameters were better in the last three years, i.e. 2008, 2007 and 2006. Therefore, this study recommends three years to be an optimum storage time for blood diet under regional conditions. Also the storage temperature conditions should remain stable at -20ºC.