# Fruit Fly cultures keep getting black mold, is this A. Niger?



## Shinosuke (Aug 10, 2011)

I haven't had much luck keeping my FF cultures alive more than a week or two since my recent move. I'm not sure if they've got that nasty black mold in them or if they're just drying out. I think the media is from eds fly meat (I bought it as part of a kit at a show), using fine excelsior as a medium, and I use a mix of mason jars, deli cups, and pet-co FF jars (I went to a store recently that had a bunch of old / dead cultures that they let me empty out and keep!) as containers. 

I've just read that microwaving the mix before adding flys can help prevent this stuff but it might already be too late for that =(

Sorry for the crappy camera-phone shots, it's all I had handy.


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## Ed (Sep 19, 2004)

Is it black and fluffy looking or is the excelsior simply black and slimy? 

Ed


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## Shinosuke (Aug 10, 2011)

I'll double check when I get home but I think it's slimy. Black, slimy, and choked with dead flies.


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## tomh1972 (Aug 13, 2011)

FWIW, my cultures always look like that after a month or two. I believe that the true "black mold" is the puffy, "bread-like" stuff that Ed was asking about.


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## Ed (Sep 19, 2004)

Tomh1972 is correct, if the cultures are slimy and black that is because the culture at that point is wet and the excelsior is breaking down. The flies could have died for multiple reasons including intolerance to the conditions in the culture. Usually this means that the cultures were a little too wet. 

Ed


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## Shinosuke (Aug 10, 2011)

So what you're saying is that misting my cultures down last night may not have been a good idea? 

I'll verify that it's not fluffy mold, but I have been using (just a tiny bit) more than 1/2 a cup of hot water with the 1/3 cup of fly food when making these cultures. I have a hard time getting all the food wet with just the 1/2 cup (you know how you always see that dry spot on the bottom of the jar? That bothers the crap out of me!) and I'm not keeping my cultures in as humid of an area so I splash a bit more in there to be safe. I'll try to make a new culture tonight and actually follow the directions.

Thank you both for your help!


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## Feelin Froggy (May 12, 2011)

Looking at your pics carefully it does look like the media is too wet. It shouldnt be soupy or runny at all. When you mix it and set it in the cup it should be "bumpy" on the bottom, after you've completely stirred the dry mix with the water...should be such a consistency that you have to tap it on the counter to make it smooth in the bottom the cup... never add water again. Even if it looks too dry its not. Once the maggots start doing there thing it will get to a thinner consistency. Hope that makes sense... good luck!!


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## pl259 (Feb 27, 2006)

Shinosuke said:


> So what you're saying is that misting my cultures down last night may not have been a good idea?
> 
> I'll verify that it's not fluffy mold, but I have been using (just a tiny bit) more than 1/2 a cup of hot water with the 1/3 cup of fly food when making these cultures. I have a hard time getting all the food wet with just the 1/2 cup (you know how you always see that dry spot on the bottom of the jar? That bothers the crap out of me!) and I'm not keeping my cultures in as humid of an area so I splash a bit more in there to be safe. I'll try to make a new culture tonight and actually follow the directions.
> 
> Thank you both for your help!


Don't mist the cultures. 

YMMV, but I've used Ed's for several years now with no problems. The temp and humidity in my setup could be different. Having said all that, I use 1/4cup of media with a 1/2cup of water. I don't microwave it, just put in the media, add the water, then swirl it around until it sets.

I also don't use excelsior, but use coffee filters instead. It's a little more work and cost, but the coffee filters are very unlikely to introduce mold spores, ect. 

Make sure you maintain temps in the range of 75-80F.


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## Shinosuke (Aug 10, 2011)

pl259 said:


> Don't mist the cultures.
> 
> ...
> 
> Make sure you maintain temps in the range of 75-80F.


This was the first time I've misted my flies. I was reading a thread last night that said the black stuff may be from lack of humidity so, being the impressionable newb that I am, I grabbed my spritzer and spritzed away. Hopefully I didn't kill off all my flies =\ Also, my new place is considerably cooler than my old place - @ 70 instead of @ 75. Do you think that temperature difference may be causing some of these issues?

There's actually a funny story behind the temperature change. I used to keep this really interesting species called a "woman" at my old place. They're great to look at in the wild but once you try to keep one in the home they change completely. The silly things require constant care, feeding, cleaning, and high temperatures. You'd think they were cold-blooded reptiles! Anyway, I set her free awhile back but let her keep the old habitat and got a new one for myself. Luckily I decided not to breed her - things are MUCH easier this way!


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## Ed (Sep 19, 2004)

Packing that much excelsior into the culture can restrict air flow down towards the media which can also help cause the breakdown of the excelsior. You don't need anywhere near that amount. 

Ed


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## john253 (May 8, 2011)

thats a funny one about the ladies always wanting it hot inside...so true lol...

anyways..I know i have made my cultures a little to wet when they start to look like this. I would make a little on the dryer side and you should be fine. I doubt the temp change of 5 degrees would cause that


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## trdlabs (Sep 23, 2011)

Shinosuke said:


> This was the first time I've misted my flies. I was reading a thread last night that said the black stuff may be from lack of humidity so, being the impressionable newb that I am, I grabbed my spritzer and spritzed away. Hopefully I didn't kill off all my flies =\ Also, my new place is considerably cooler than my old place - @ 70 instead of @ 75. Do you think that temperature difference may be causing some of these issues?
> 
> There's actually a funny story behind the temperature change. I used to keep this really interesting species called a "woman" at my old place. They're great to look at in the wild but once you try to keep one in the home they change completely. The silly things require constant care, feeding, cleaning, and high temperatures. You'd think they were cold-blooded reptiles! Anyway, I set her free awhile back but let her keep the old habitat and got a new one for myself. Luckily I decided not to breed her - things are MUCH easier this way!


I don't know about black mold but green fuzzy mold is lack of not enough water to the mix. I learned my lesson on that one.


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## Ed (Sep 19, 2004)

trdlabs said:


> I don't know about black mold but green fuzzy mold is lack of not enough water to the mix. I learned my lesson on that one.


This may be an artifact of reduced activity on the part of the fruit fly maggots instead of optimizing conditions for the mold. 

Ed


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