DEVELOPMENT OF TECHNIQUE FOR MASS PRODUCTION OF HOUSEFLY Musca domestica MAGGOTS

Aquaculture in Tanzania has remained subsistence partly due to lack of quality affordable aquafeeds. This is because conventional sources of protein such as fishmeal and oil seed cakes are scarce and costly. Housefly maggots are locally available, affordable and contain high protein, thus potential alternative protein source. However, a limiting factor is lack of appropriate culture technique for mass production of maggots with convenient harvesting. Thus culture unit was designed composed of a plastic enclosure with 40 cm diameter and 21.5 cm height consisting of two chambers (Plate 1).

The top chamber served as a culture unit where the substrate was placed. The bottom chamber served as harvesting unit and was separated from the top chamber using a 2 mm nylon mesh. The mesh allowed dropping of maggots into harvesting unit due to photosensitivity of maggots when exposed to light upon opening of the culture unit. Five substrates in triplicates namely, cattle manure, poultry manure, pig manure, cattle offal and kitchen leftovers were used were used assess suitability of the developed system as well as the culture conditions. About 2.5 kg of substrate and 250 gm of attractant (mixture of blood, small pieces of meat debris and rotten eggs) were placed into culture unit and houseflies allowed to lay eggs. Harvesting was done from day four where maggots were cleaned with water, blanched and then weighed. Prior to harvesting, temperature was recorded. Substrates were refreshed weekly for the whole trial period of three weeks. Harvesting maggots was more convenient as they were easily collected from the harvest chamber after opening lid of the culture unit. Cattle offal resulted in significantly higher maggot yield while least was from cattle manure (p<0.05) (Table 1).

Temperature was significantly higher in poultry manure (p<0.05); however, there was no relationship between temperature and yield, r = .191, p (one-tailed) > .10. Thus cattle offal where easily available is most suitable substrate for culturing housefly maggots. Efforts are now underway to upscale this production technique for production of larger volumes of maggots.