Fruit Fly Culture Not Reproducing.

[SkittishMale]

I bought a Drosophila melanogaster culture and it reproduced once for me after starting a new deli cup for them but now I cannot get them to reproduce again to start another generation.

The medium I use is Repashy Superfly and I keep it moist enough that the surface isn't dry and when I tip the culture, the medium slowly moves to the side so I don't believe moisture is an issue. I don't have any mold issues either. The depth of the medium is just over one inch.

Has anybody else have this problem before and know how to get them reproducing again? Because buying new cultures often can get costly and I would prefer to make my own but I am not enthusiastic about fruit flies enough to make my own media.

 

[Vlodek]

I think the medium is not dense enough. From what you say it seems that there is possibility that flies simply drown in it.

Also, when did you start the culture?

 

[Sticky]

Mine did the same thing. I put some melanos in it and they are barely there after 1 month!

 

[SkittishMale]

I started the culture about a week ago and I see no larvae or evidence of them. I have it this moist because I had it dryer before and read that it was too dry and needed to be wet enough that the surface was moist because I had to production on the drier medium but when I soaked it, I got a new generation of flies. That was the first generation I produced after buying it initially. I am trying to get a second generation right now which isn't working,

 

[Ranitomeya]

If you keep the medium too wet, you won't have any initial production as the adult flies will drown and the eggs will drown. You need to start the medium at the optimum moisture level and keep it that way. The humidity where you're keeping the culture is most likely too low and the culture is drying out much too quickly.

 

[SkittishMale]

What percent should the humidity at? and how moist/dry does the medium have to be?

 

[Vlodek]

Keep the medium to look just as on picture below. Its density is perfect for flies to walk on and to prevent drying out.

 

[Extrememantid]

I started the culture about a week ago and I see no larvae or evidence of them. I have it this moist because I had it dryer before and read that it was too dry and needed to be wet enough that the surface was moist because I had to production on the drier medium but when I soaked it, I got a new generation of flies. That was the first generation I produced after buying it initially. I am trying to get a second generation right now which isn't working,

I think it takes longer than a week.. Well for hydei it takes around 10 days.

 

[Extrememantid]

Also.. I have tiny little black things crawling through my culture medium.. Like super tiny. And I made the medium myself, this is the second generation as well. Any idea?

 

[Vlodek]

The small specs that you're talking about might be grain mites. Any pictures?

 

[SkittishMale]

D. hydei does take longer than D. melanogaster to grow and reproduce. I have never seen tiny black things crawling around through the culture medium but if you post a picture, I can help you identify it.

 

[hibiscusmile]

I never have the same amount of moisture in my cultures ever, each culture batch is done by eyeball.... :1eye: , some are to wet, some are to dry, some are just right.... (goldilocks) but they always produce, so I would venture to tell you it is the medium u r using. Make your own, use some dried potatoes, some sugar, some vinegar and some yeast, they will reproduce, ck the threads for fruit fly cultures here, u will find plenty of recipes.

 

[Extrememantid]

The small specs that you're talking about might be grain mites. Any pictures?

They are too small to get a picture of.. Would grain mites do any harm?

 

[gm88]

I never have the same amount of moisture in my cultures ever, each culture batch is done by eyeball.... :1eye: , some are to wet, some are to dry, some are just right.... (goldilocks) but they always produce, so I would venture to tell you it is the medium u r using. Make your own, use some dried potatoes, some sugar, some vinegar and some yeast, they will reproduce, ck the threads for fruit fly cultures here, u will find plenty of recipes.

That's what I have been doing and so far it's working great. The D. Melanogaster reproduced for me in about a week, D. Hydei takes a bit more like a month for me so far (first time I tried it I did not think it was working after a few weeks), but I've only done it a few times.

 

[Ranitomeya]

The mouthparts of maggots are black. The rest of their body is pretty much the same color as what they eat because their bodies are not opaque. You may be seeing the maggots as they crawl through the medium.

 

[Rick]

Give it more time. Hydei are slow. You don't need to worry about meeting some certain level of humidity. I always just eyeball the amount of water I add. Sometimes I know it is too wet and runs easily so I add more mix. If too dry and it acts like mashed potatoes I add more water. But usually I leave it as it is and the cultures never fail to work. I think in this case you just need to wait longer. You will see tiny larvae soon.

 

[Extrememantid]

The mouthparts of maggots are black. The rest of their body is pretty much the same color as what they eat because their bodies are not opaque. You may be seeing the maggots as they crawl through the medium.

No I don't think they are maggots, but maybe.

 

[PlayingMantis]

I use Repashy's Superfly for D. melanogaster and it took me about two weeks to see many pupae along the sides, about around 3 weeks to really start going. Temperature also plays a role - the higher the temp, the shorter the wait time.

I have found that my homemade mix started producing a little faster, and is still going strong after 8 weeks!

 

[devetaki9]

Hydei definitely take longer. I am having a heck of a time with the decreased humidity this winter myself. This past summer I had about 20 cultures going before I knew what hit me. This winter I have mixed the repashy just like I did all last summer and it's like a brick, I mist it every mornin and evenin. Keep in mind I have ALL my bugs and cultures in my bathroom, it's plenty hot for the baby mantises but it's low on humidity. I keep the nymphs misted well and in bins to help keep their humidity up.