FOOD RECIPE-NSRI-UP DILIMAN

[UP Natural Science Research Institute email account]

                               FLY FOOD RECIPE
Natural Sciences Research Institute, University of the Philippines, Diliman


This inexpensive fly food recipe is for Drosophila melanogaster researchers
based in TROPICAL COUNTRIES where CORNMEAL, CORNFLOUR, TEGOSEPT, and TEDION
are EXPENSIVE, NOT-EASY-TO-GET, or UNAVAILABLE. This fly food recipe has 
been proven to be suitable for local wild type Drosophila melanogasterand 
imported Drosophila melanogaster mutant stocks. This recipe is a modification
of a fly food formula faxed to me by Phyllis Oster, Curator of Stocks, Mid-
America Stock Center. 

IF THE INGREDIENTS OF THE BLOOMINGTON AND MID-AMERICA FOOD RECIPE ARE 
AVAILABLE IN YOUR LOCALITY, I RECOMMEND THAT YOU USE THEIR FORMULAS.

THIS RECIPE HAS NOT BEEN TRIED ON OTHER DROSOPHILA SPECIES.

Ingredients (For 1 - 1.25 L fly food)

100 gms CORN STARCH
 20 gms DRY YEAST (Baker's yeast)
 11 gms AGAR
 50 gms SUCROSE
  6 mL  PROPIONIC ACID
  0.5 mL PHOSPHORIC ACID
 25 mL  1.5 % BENZYL BENZOATE SOLUTION ( 1.5 mL Benzyl Benzoate to
        98.5 mL ethanol )
1000 mL WATER

Procedure

Add agar in 500 mL water, boil under low heat until the agar melts. You
can add 200 mL water after the agar melts to replace evaporated water.

Mix corn starch, yeast, and sucrose in 400 mL water using a 1 Liter
beaker. Stir vigorously until all ingredients dissolve. Add enough water
to make the solution 500 mL. Stir again.

Pour well-stirred corn starch-yeast-sucrose solution into the pan
containing the melted agar. Stir constantly under low flame until the
whole solution becomes a not-so-thick, creme-colored soup. Make sure that
the soup is not very dilute ( it's consistency shouldn't be like water but
thicker). Add one by one benzyl benzoate, phosphoric acid, and propionic
acid. Make sure to stir the food thoroughly after each preservative
component is added. After the addition of the last component, allow the
food to boil for five minutes with constant stirring. Pour into bottles or
vials. Allow the food to cool and solidify. Wipe out moisture at the sides
of the bottles and vials with clean tissue paper or absorbent cotton. Seal
properly the mouths of your bottles/vials. Refrigerate bottles/vials
containing fly food if they are not to be used immediately. 

It would be good to leave a long thin film of fly food on a small portion of 
the wall of your bottles/vials ( you can achieve this by pouring the fly 
food on the container's side). I have noticed that females love to lay a 
lot of eggs on this portion compared to the medium found at the bottom of 
containers. Eggs and larvae can be seen visibly at this thin film.

BENJAMIN J. BOLIVAL, JR.
Natural Sciences Research Institute
University of the Philippines, Diliman
1101 Quezon City, Philippines
email: nsri at nicole.upd.edu.ph
   
        

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