Making Fruit Fly Cultures (15 cents/culture)

-Healthy visually mite-free culture of melanogaster (this media mix doesn’t work well for hydei)
-Deli cups or mason jars (both are easy to re-use).  Superior enterprises has most materials you would need, as do many restaurant supply stores.
-Perforated lids or normal deli cup lids with the center cut out (super helpful in a pinch if you don’t have the perforated lids).  Many lids you can purchase come with paper glued to the lid, -it gets dirty after a few uses, as you would expect.  You can remove this and use coffee filters.
-Potato flakes. Most work great, if possible get the spuds in a bag versus box as it seems they are less likely to be carriers of mite eggs.
-Brewers yeast. NOW brand or any other will work fine.  A jar of this stuff is about $10 and will last at least 100 cultures (maybe closer to 300, I am not entirely sure).
-White vinegar

-Start with an empty cup and pour in potato flakes until they fill up to about .75 inch.
-Pour in a small spoonful of brewers yeast
-Swirl flakes and yeast
-Mix white vinegar 50:50 with warm water
-Pour liquid mixture into the cup so that it is all absorbed. It should not be sloshing around.
-Sprinkle a pinch of cinammin and brewers yeast on the surface of the medium.
-Wait a minute and see if the culture looks dry, if it does, add a little more liquid.
-Add 2-4 coffeefilters.
-Add 50-100 flies.
-Use the coffeefilter under the perforated lid or metal mason jar lid, and fix lid in place.

Conditions & Cleaning
-Store cultures in as warm a spot as possible, mid-70’s or standard frogroom temperatures is ideal.
-It’s best to use freshly producing cultures to start your new ones.
-The complete fly life cycle can range anywhere from about ten days-2 months depending on how warm you keep them.  For temps mid 70’s, it takes about 2.5 weeks from adult fly to next generation of fly.
-To clean the cultures you can do a few things, one of the easiest I have found is to use a spatula to remove a majority of the media, and then soak the cultures in hot water for half an hour or so.  After letting them soak, you can scrub them with (a fly designated!) sponge or scrungie.

Mites and Mold
-Lots of debate on the mite issue, some say all cultures have mites, we just dont see them…I truly dont know, but, if I see mites, I ditch all my cultures and start new, and completely sterilize the entire area with vinegar multiple times and dont put any new cultures there for weeks.
-Some swear by microwaving the media before introducing flies, I’ve tried it but got away from it, and have not noticed a difference.  If the mites happen to be introduced from the media this is definitely a great way to kill them off, but if your media is clean it doesn’t seem necessary.
-It’s not a bad idea to dust the flies lightly with a supplement powder or diatomaceous earth before starting fresh cultures, as it helps remove mites.
-Mold can be an issue for some people.  The vinegar ratio can be bumped up to help, and more cinammin can be used.
-Mites can sometimes infest older cultures, one precaution to take is to house old cultures separate from newer ones, and not let the cultures touch.
-If you do happen to have a mite issue and want to re-use the jars or cups, you can freeze them for a day and that will kill the mites.

If you re-use your cups the cost for media and materials is around 15-20 cents per culture.