Cornmeal Fly Media

METHOD

• 1. Mix 27.5 g of yeast powder and 52 g of maize flour in a mixing bowl.

• 2. Add 170 mL of water to the mixture.

• 3. Blend with a food mixer (or by hand with a spoon) until mixture is thin and smooth with no or few lumps. The consistency should be thick yet viscous enough to be poured through a sieve. Add more water if the consistency is too thick.

• 4. To filter out any remaining lumps, pour the mixture through a sieve into the smaller cooking pot. Use the metal spoon to break up any lumps remaining on the sieve and to push them through.

• 5. Add 935 mL of water to the other, larger cooking pot.

• 6. Add 7.9 g of agar to the pot in Step 5, distributing evenly over the water, and mix.

• 7. Using the hot plates, heat the mixture to 90°C and check that the agar is dissolved. The solution should be transparent, with a golden color.

• 8. Add 110 g of anhydrous D-glucose to the molten agar and continue mixing.

• 9. Add the yeast/maize flour mixture from Step 4 into the pot with agar and D-glucose. Continue mixing.

• 10. Bring the temperature of the mixture to 94°C, which should sterilize it. Maintain the boil for a period of 5 min. Keep stirring to avoid burning the mixture and keep the lid on to prevent evaporation.

• 11. Cool mixture to 72°C.

• 12. Combine 2.4 g of Tegosept and 9.2 mL of ethanol in a small beaker and mix until the Tegosept has dissolved. Add the Tegosept solution into the mixture that is now at 72°C (Step 11). Keep stirring and ensure that the Tegosept is mixed in well.

• 13. Pour the mixture into the 1-L bottle and pipet into vials (∼2.5 mL per vial) before the food solidifies.

• 14. Cover the vials/boxes of vials with muslin cloth and allow them to dry. Once dry, remove the muslin cloth, wrap the boxes of vials in plastic to avoid overdrying, and store for up to 1 mo at room temperature.

  • This recipe is for preparing 1 L of fly food, enough for about 400 (±20) vials at 2.5 mL per vial.