# Why can't I raise fruit flies?!



## blaze88 (Jun 17, 2015)

I was hoping to get some help raising fruit flies. I just can't seem to get the hang of it, which is upsetting since they are like the easiest thing to raise ever!

I bought the culture kits from josh's frogs and followed the directions for preparing. (I may have made it too soupy though? It was about the consistency of runny peanut butter for one and thick oil for the other)I made two cultures and added about 20-30 flies per a culture from a petsmart Hydei culture. I never got any larva or anything. After about 20 days I fed the adults to my frogs and gave up.

So I bought some gelatin, put half a packet into the cup along with the josh's frogs mix and added some repti-vitamins. I made this one fairly soupy and mixed the solution well. It set up like a firm jello. There is a spot or two of mold but its not expanding to cover the surface or anything. I just spray the culture to keep it moist and the mold hasn't gotten any bigger. This was all set up about 5 days ago and I'm just praying that I can grow some stupid flies this time!

What on earth am I doing wrong?


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## JPccusa (Mar 10, 2009)

Try changing the consistency of your media (a *little* softer than mashed potatoes). To get that consistency, either increase the amount of media powder or reduce the amount of water. 

If everything keeps failing, try a different media and source for flies.


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## Dane (Aug 19, 2004)

I believe that prolonged heat can also cause Drosophila to be come sterile, but if they were packaged properly, and didn't see extreme temperatures, this wouldn't be the issue. Like JP said, your media was most likely too soupy. Throwing a few paper coffee filters (if you don't already use them as climbing/pupae substrate) into your media after it has been spooned into the cups can help absorb extra moisture as well.


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## Tzunu'un (Apr 15, 2014)

The above comments are good.

I've seen that the Josh's Frogs powdered media can sometimes settle/separate during shipping, etc. causing inconsistent thickness of media between cups so I would recommend mixing it well in the bag. Also follow the suggestion on adjusting consistency by water/mix ratio.

Hydei shows a temporal difference in hatching of the male and female flies (unlike melanogaster) where females hatch earlier than males in cultures. Also more hydei flies are used (as compared to melanogaster) to initiate a culture to compensate for this and make sure that enough males and females are added. Use 100 hydei or so per container to start cultures.

The Josh's Frogs mix should work for you. If you still have problems then I also agree that you should try another source of flies.

Some general info and tips on culturing flies that I posted previously in another forum:



> *Temps:*
> Your cultures should be kept between 70-80 F.
> Lower than this will slow production/growth rate.
> Higher than this can cause cultures to dry out/ stress the culture/ sterility if temps are very high/ can cause some selected strains of flies to hatch with the ability to fly.
> ...


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## zerelli (Sep 14, 2009)

I would recommend calling them if you are experiencing issues.


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## blaze88 (Jun 17, 2015)

Thanks for all the tips! I think my flies were exposed to heat (Georgia, June etc) but I'll try seeding my next culture with 2nd gen flies from the petsmart culture if my gelatin culture ends up failing. I also have some josh's flies in the mail right now so I will try them too, but my petsmart flies breed fine in the petsmart jar. 

Thanks for the help!


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## Ed (Sep 19, 2004)

One of the things that people often forget about hydeii is that there is a highly skewed sex ratio when they first emerge from the pupae. It was noted by Tzunu'un.

This article may be of some use. http://www.nativefishlab.net/library/textpdf/14269.pdf

Some comments 

Ed


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## blaze88 (Jun 17, 2015)

Haha my gelatin addition worked! I have pupae!!!!

Thanks all!


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## srrrio (May 12, 2007)

Don't count your pupae until they hatch!


blaze88 said:


> Haha my gelatin addition worked! I have pupae!!!!
> 
> Thanks all!


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## RRRavelo (Nov 21, 2007)

Additional things to consider:

Melonagaster FFs have a much more user friendly life cycle and produce a lot more than Hydei. and are readily accepted by all the frogs I have offered them to including Terribs. They are also easier to manage and escape a lot less from the frogs and the vivariums.
I use them as my staple and feed out the Hydei when they are producing. 

The source of your starter cultures is key. Order a producing culture from NE Herp or Ed's Fly Meat or other reliable source and make your next cultures right away from them.

A light spray(no a misting) along the sides of the container after mixing is a good idea to clean up the area on the side of the container where the FF will be getting out of the media. Just don't over do it.

Put brewer's yeast in the media when you mix it and on top also after mixing. Use the coffee filters or excelsior moss for addtl. surface area as stated above. 

GL


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