(Drosophila melanogaster & Drosophila hydei)

This is by far the most commonly used staple food of dendrobatid frogs.

1. D. hydei is darker in colour and has red eyes.
2. The size of D. hydei is approximately 1/8 inch (3.5 mm).
3. The time to reach adulthood is approximately 28 days.
4. This fly is also flightless even though it has wings-the muscles are impaired for flying.
5. It is more difficult to breed this species, but if the conditions are correct, the yield is high.

1. D. melanogaster is lighter in colour and smaller (the size of a small ant)
2. The size being 1/10 inch (2.5 mm) in size.
3. At 70°F (21°C) the flies will reach adulthood in approximately 14 days, eight days in the egg and larval stages, and six in the pupa stage.
4. As an adult a female can lay 500 eggs in 10 days. 
5. It has vestigial wings rendering it flightless.

It is a good idea to breed both species, but make sure to keep the species separate!

Temperature Range:

68-80°F (20-27°C), it is best to maintain at the lower temperature range, if maintained at the higher temperatures, bacteria, fungi, and mites seem to be more of a problem.

Establishing Cultures:

Plastic Pint glasses with round coffee filter or pantyhose secured over the top with a rubber band make ideal culturing containers. Next, place enough media in the container so there will be between 15mm-25mm on the bottom. After the media is mixed up and in the bottom of the container, add a few grains of yeast and then place some Excelsior in the jar. This will allow additional surface area for the larvae to climb and morph on. Then add some flies from another culture. Cover the jar with a coffee filter or pantyhose and secure with a rubber band. See Diagram below.

Male adult D. hydei take at least a week after enclosing to become sexually mature. Because the females don't take so long, what you do is mix old males (+10 days) with new females to get good egg production. To do this efficiently, just mix old and new flies.

FRUIT FLY CULTURE CONTAINERS

Possible Infestations:

Bacterial Infections, the evidence of infections can appear as a grey or yellow-green sheen (slime) or black dust (the black death) on the media. If these are noticed in any of you cultures, discard the culture at once and sterilize any or all equipment used with your cultures to prevent the spread of the bacteria to other or all of your cultures.

Mites, can infest cultures at times, these will appear as small white or red bugs. You should dispose of any cultures that become infected with mites, immediately. Once the production starts to reduce, cultures become susceptible to infection, once cultures start to lose their productivity (normally 6-8 weeks), it is best to dispose them. If you find that you have a mite infection, remove the infested cultures and store the remaining cultures on paper treated with lidane. This will act as an insecticide, or stand the cultures in a shallow tray of water with a few drops of washing-up liquid added.

Since mite infestations can cause cultures to crash i.e. not produce any fruit flies. There are a number of steps that can be taken to eliminate or at the very least reduce the problem of a mite infestation. First and foremost is to move the uninfected cultures to a different part of the house. Various Mite powders or solutions can be used to treat infestations outside the culture. These are sprinkled or applied around the perimeter where the cultures are kept and mites are killed on contact. Tedion solution does not kill mites on contact but rather treats mites internally, this solution can be is mixed when the culture is made.  Also, keeping the culture well ventilated and in a well-lit area also helps.  When starting new cultures first put flies in a calcium powder for about 5 minutes. Then shake the dust off very well in a sieve. Use these flies to start new cultures. The powder removes any mites which mites are on the fruit flies already.

Mould, this will happen to all of us occasionally. Don’t worry you will get some mould, as long as it is a green or blue, like the mould seen on rotting fruit and as long as the cultures surface is not completely covered. Most Biological Supply Houses sell mould inhibitor, which can help to reduce the amount of mould. An alternative method involves using vinegar to acidify the media and therefore reduce the chance of mould forming. All these methods work with varying amounts of success. Just remember, as with most thing when keeping herps, what works great for one person may not work for another so just keep trying?

The following are some guidelines that will help in the reduction of moulds, mites and bacterial infections:

1. Keep all materials that are to be used for your FF cultures in the freezer for at least 24 hours before hand, this includes the containers, dry media, excelsior, mesh tops, etc.
2. New cultures are to be made up in a “clean room” using boiling water.
3. Set up new cultures using flies from known clean cultures.
4. The flies that are used to start new cultures are all dusted with CaCO3.
5. Soak the coffee filter/mesh top in a solution of (4% benzyl bezoate/96% ethanol).
6. Date all your cultures and place in freezer or destroy after 1 month.

Cleaning Cultures:

Plastic pint glasses are cheap and be bought in bulk, so old cultures can just be discarded and new ones started.

Glass jars are reusable, then they should be cleaned between each use. This is best done outside. Fill each jar with water and allow it to stand for at least 24 hours. Once the contents of the jar have soaked through, dump the contents and wash the container out with a garden hose using a brush to remove anything left in the jar. Soak the jars for at least 5 minutes in a mixture of, 1 part household bleach and 20 parts water. The jars should be rinsed well and allowed to dry.

Number of Cultures:

As FF are one of the staple feeder insects of Dendrobatids, a good guide line would be to maintain, 1 culture per every 2 frogs with a minim of 3 cultures per week. Once you have been culturing FF for a while, you will be able to judge the number of cultures that you will need.

Remember; always make extra cultures just in case some crash or if you experience a low yield and usually after the first harvest, fly production will be reduced by almost half.

It is important to start the your initial cultures about 2-3 weeks early before purchasing frogs!

Media:

As their name states, fruit flies can be cultured on fruit, as some of us have found out when we have forgotten about some old bananas in the kitchen.

There are numerous media recipes and all work with varying degrees of success. It is best to try a number of different recipes and see which works best for you and your circumstances!

Generic Mix

1-cup Brown sugar
20g Mould inhibitor
8 cups Potato flakes or powdered instant mashed potato
1-cup Yeast
4000ml Distilled water
Plastic pint glasses
Excelsior
Rubber bands
Round paper coffee filters

Combine and set aside: 1-cup sugar with 4 teaspoons of inhibitor
Use a blender; pulverize 8 cups of potato flakes into a nice powder to be combined with 1-cup brewer's yeast. Pulverizing the potato flakes makes the mixture more uniform, but it's optional.
Mix the above ingredients together in a bowl.
In a pint glass, mix the water to medium ratio is 2:1, but depending on how humid or dry it is in your area, this ratio can be adjusted. So, for this example, add 2/3-cup water, then add 1/3-cup medium, using a wooden kebab skewer to quickly mix the mixture since the dry ingredients suck up the water very quickly.
Sprinkle a pinch of baker's yeast on top of the prepared medium. Don't add too much because yeast produces carbon dioxide and in large amounts, it renders the flies sterile.
Place Excelsior on top of the medium to the top of the medium this increases the surface area.
Let the whole thing settle for 5-10 minutes.
Add your flies, cover with coffee filter or panty hose and secure with a rubber band.
Keep the culture at around 75°F (24°C) in a well-lit area.
If kept warmer, above 85°F (30°C), the production of flies is greater but it's more prone to mite and bacterial infestations.

1) Wait for a week or so, you should start to see small larvae (miniature maggots).

2) Soon; you will have pupae (small brown "cocoons") on the glass and/or in the media.

3) About a week later you will have dozens, if not hundreds of flies!

Fruit and Apple Sauce Mix

1-cup Banana (about 2 bananas) or any sweet fruit
1-cup Applesauce
1/8 cups Vinegar (or 2 tablespoons or 15 ml)
2 cups Oatmeal
5g Baker's yeast

Put banana (fruit) and applesauce in blender or bowl and mix until the banana is liquefied. Heat in the microwave for approximately 2 min. or until hot enough to kill off any wild fruit fly eggs that were in the bananas, and to reduce mould. Add the vinegar and mix in oatmeal until it becomes firm, but still moist. Put the mixture in pint glasses and allow to the mix to cool. Once cooled, add the yeast and flies. Any unused media can be frozen until needed. 
Makes approx. 6-pint glass cultures

Home made "Carolina Mix"
Christina Hanson

1-cup Powdered sugar
4 teaspoons Methylparaben
8 cups Potato flakes
1/2 - 1-cup Brewers yeast

Sift the powdered sugar and the Methylparaben into a gallon or larger zip lock bag and shake well.
Add the potato flakes and brewers yeast to the zip lock bag and shake well. 
The media is mixed by mixing use 1/3 to 1/2 cups of media mixed with equal amounts of hot water in a quart jar.
Makes approximately 30 cultures

Carolina Drosophila Manual Mix
From the Carolina Drosophila Manual

3-cups Water 
1-2g Tegosept
15g Agar (available at health food stores)
130 ml Molasses (sulphur-free)
100g Yellow cornmeal

Dissolve 15 g of agar and 1 - 2 g of Tegosept in 500 ml of boiling water. To this add 130 ml of molasses. Be careful not to let this mixture boil over. Mix 100 g of cornmeal with 250 ml of cold water and pour into the boiling mix and cook for a few minutes. While the mixture is still thin enough to pour, pour 2 - 3 cm into the jars. After this has cooled, add some fibreglass screen to give the flies a place to climb. Allow this to cool for a few hours before adding flies and a couple granules of baker's yeast. Cover the jar with a paper towel folded 4 ways then place the lid with holes punched into it over the paper towel. 
Makes approx. 8-pint glass cultures

Shorrocks Standard Mix
Prof. Shorrocks

13.5g Cornmeal (maize meal) 
18.0g Molasses 
2.0g Agar 
0.3g Nipagin (mould inhibitor) 
1000ml Water

This quantity is enough for four small milk bottles
Pour two-thirds of the water into a pan
Add the cornmeal and molasses to the cold water
Bring the mixture to the boil and cook for several minutes
Add the agar (and Nipagin if using) to the remaining cold water and mix them thoroughly.
When cornmeal and agar are ready, pour in the agar and cook the whole for a few minutes longer, stirring constantly.
The mixture is ready for use while it is still thin enough to pour easily, but will gel firmly on cooling.
Note: all ingredients should be mixed in the cold water first to prevent lumps forming, and the food should be stirred constantly.
The day before flies are to be put into the containers, a generous sprinkling of yeast granules should be placed onto the surface of the set gel.

However, Prof. Shorrocks recommends the use of fresh yeast (obtainable from bakeries in small amounts.)

Farina Mix
Don Wells

1 litre Water
10 g Powdered agar (available at health food stores)
50 g Farina Cereal (Cream of Wheat or Cornmeal seems to suffice)
100 g Dry malt (available at home brewing stores)
15 g Bakers Yeast
7 g Calcium Proprionate
25 g Methylparaben mixed into 500 millilitres of 96% proof non denatured alcohol (i.e., vodka)

Mix farina (other cereal substitute) malt, agar in a kettle and pour in water.
Stir constantly and bring to a boil / simmer for 5 minutes.
Stir in Yeast and bring back to a beginning boil. I also add at this time Spirulina and Klamath lake Blue Green Algae Apzomenon floss-algae (sp?). Usually a teaspoon of each and stir it in well. 
Take from heat pour in 25 millilitres of Methylparaben/Alcohol and calcium proprionate and mix well.
Immediately pour into sterile bottles or vials.
Do not allow the mixture to cool or it will be hard to pour, it should not be too watery at this point either. If it seems watery add a bit more agar and cereal and bring to a boil once more.
I usually try to pour in about an inch and a half of media per bottle.
Stand overnight and allow the surface to dry before introducing the flies.

Baby Cereal Mix

3 cups “Baby cereal”
1-cup Water
1-cup Vinegar
½-cup Banana (or any other sweet fruit)
1-tablespoon Fruit yoghurt
3 tablespoons Beer yeast flakes

Mix all the ingredients (with an food blender) if the mix becomes too wet add "Baby Cereal" but if it becomes too dry add hot water. The final media must have a baby food or purée similar texture, not too wet to avoid drowning the flies but not hard.
Distribute the mixture in tall transparent plastic cans (1½” deep is fine), add a little beer yeast at the surface and leave for about 24 hours. Add Excelsior, about 30-40 fruit flies and cover it with a peace of pantyhose and rubber band, to avoid excessive humidity.

Molasses Mix
Nancy Nehring

1-cup Water
1-tablespoon Cornmeal
1 teaspoon Powdered agar (available at health food stores)
1-tablespoon Molasses
1/8-teaspoon Calcium proprionate (an optional mould inhibitor used in bread.)
1 package Bakers yeast

Mix all ingredients except yeast, then heat until boiling. Quickly pour mixture into clean culture jars. Cap and let cool to room temperature. This mixture can be stored in the refrigerator with a tightly capped lid until ready for use. When ready to use, sprinkle a couple granules of baker's yeast on the surface and add fruit flies.

The "Power Mix"
Chris Miller (Posted on Frognet)

I have been using a mixture of potato flakes, sugar, and “Freshman’s activated yeast” for years now. But, after adding a lot of mouths to feed to my collection, I had decided I was going to have to find something that made a lot more flies per jar. With input from a lot of different sources (Dave and Erin, Tracy Hicks, Jutti,) etc, I have composed a mush that has QUADRUPLED my fly production. I have had very little problem with mould, and the cultures seem to last for at least a month or longer.

In a pot bring the following to a boil.
2 cups Water
2 cups Vinegar
1/8th cup Dark molasses
1/2 can of Grape juice concentrate
2-3 Overripe mashed up bananas 
After bringing this mixture to a boil, add the dry material 
1/2-cup Malt of meal
2/3-cup Potato flakes
1/3 cup Brewers Yeast (the key ingredient)

Place about 2 inches of medium in each pint size jar, and sprinkle maybe an 1/8th teaspoon of activated yeast on the top. A day later, 20-30 flies are added. I have tried this medium with my hydei and melanogaster and I can't believe how many larvae are swarming the sided of the jar, I literally can't see through the glass jar, they cover every square inch of glass. For the first 10 days, I keep the cultures in cardboard boxes that are kept closed, after that, I keep them on a large shelf to help the larvae dry out.

To Feed:

N.B.  If you are going to be away from home for a few days, you can leave a fruit fly culture in the vivarium, just remove the paper towel or make a small hole in the side of the culture so that the fruit flies can escape into the vivarium. Wrap the culture in a wet paper towel to prevent the frogs from seeing the flies and trying to feed through the side of the culture container. A slice of fruit such as apple can be added to give a place for the flies to gather helping the animals to find the food.

Housekeeping:

Preventing Escapes

1. Put a slice of fruit in the tank that will attract the flies. Bananas work great. This keeps them in and helps the frogs find them to eat.
2. Use tight covers and fine screen or fabric in ventilation areas.
3. Place containers of water near the tank or on top. The flies will go to the water and drown if they get out of the tank.
4. Keep small day geckos in the tank’s they feed on the flies that make it to the top of the tank.
5. Keep the fruit fly cultures in a plastic box with about 1/2 inch of water in it to which a few drops of washing-up liquid have been added. Any flies that get out drown and this help keep mites from getting in cultures.
6. Apply a film of petroleum jelly or fluon along the top of the culture container.