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Discussion Starter · #1 ·
OK, so a while back my fruit fly culture production really took a hit and I have no clue why. I have tried different media's and have experimented with all kinds of different techniques such as microwaving, waiting to put the fly's in after mixing the culture, melanogaster/hydei, RO water, yeast, vinegar etc etc etc. Now when I make my culture and put the fly's in they all die within a day or two. Can anyone tell me what i am doing wrong? I was doing so well for a while with no problems and serious larval growth and fly production, but now it is like the fruit fly gods have cursed me. I have dealt with mites of course, but this is totally different. I have done everything that others have done and my flies just die after i put them in the culture and I am at a loss for ideas. Help would be greatly appreciated!!!!!! Thankyou guys in advance....Oli
 

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Well, Could you post a pic of the setup for the flies your using? I was thinking it could possibly be your media, it could be too wet causing them to drown. I doubt thats it though. Im sure some people will argue, but I'd try to stick to the simplest media recipe you could, I just use brewers yeast, pot flakes, methyl paraben, and powdered sugar.
 

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About what temp is the room that you keep your cultures in? What kind of media are you currently using? Do you reuse the cups?
 

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Discussion Starter · #5 ·
wiedemey, I think that you may be correct with that as it isn't a media issue as i have changed the brands and recipe's that I have been using and it doesn't seem to make a difference, the fly's will just die within a few days. I use the 32oz deli cups with the insect/cloth lids for ventilation. The temps of the room that I keep the deli cups in is about 70-80 degrees, but it doesn't seem to make much difference as they just die fast. I re-use my cups, and I re-use the lids for a few times, but I will sterilize them in the microwave between batches. How can I increase air flow to my cultures as I do use live yeast in my cultures. I even tried to avoid sprinkling bakers yeast on top in the end and it didn't make any difference the fly's died. I'm sure that their is still brewer's yeast in the media itself though as it is a pre-mixed purchased product. Right now I am using WARD's media, but have used black jungle, ed's, and several others. I used to have zero problems with the cultures but now this is happening and I just have no idea why, it doesn't seem like I have even changed anything in making the cultures. I have tried coffee filters, excelsior, and I have even used window screen, or plastic grating to see if that had any influence on the cultures but it didn't. Please help me out this is getting really really frustrating and I can't keep buying cultures. Thanks in advance!!! Oli
 

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Discussion Starter · #6 ·
ohh yea, and it's not that the media is too wet, I have gone from wet to dry and everywhere in between to try and remedy this situation. Air could definitely be the issue, I don't know how to increase it though? I never had this problem before so I really am at a loss for ideas right now.
 

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Tough to increase air flow but easy to reduce CO2 production: start with fresh cups (Josh's is having a one day sale today) and lids, and a booming culture of flies (I have had the best luck with wingless D.melanogaster from FlyCafe or Ed's Fly Meat). Avoid live yeast and cup recycling while you're sorting out the issues. Once your production gets going you can start experimenting a little bit. I wouldn't recycle these deli cups, though - the risk of carrying over unwanted microbes will remain even if you microwave them.
 

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If there is concern about microbes carrying over from prior cultures then simply rising in a 10% bleach solution and air drying will resolve the issue. Microwaving the cultures until they are really hot will also significantly reduce the risk of microbes.. However I am pretty surprised that there is a concern about microbes carrying over since the flies are going to be carrying the microbes and yeast....

Unless the cultures are stacked on top of one another CO2 is a unlikely issue unless the cultures are kept in something that doesn't have any air circulation at all (Like a large rubbermaid tub with a snap down lid.

The first things that should be looked at is whether or not the cultures are producing... Are you getting any production in the cultures after the flies die? In other words are you seeing maggots develop? If no, when are you harvesting the flies from the old culture? Are you pulling them from the first emergence?
 

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As long as we don't know what is killing the flies I would argue against reusing tainted supplies, especially when they cost pennies. Could be culturing conditions or pathogens that kill the flies. IMO, it is much easier to start from scratch and eliminate as many risk factors as possible instead of trying to salvage the dying cultures. If you start with a clean new batch of flies, clean plasticware, and follow one of the recipes/procedures on this site there shouldn't be any problems. If you do decide to investigate the cause of death, as Ed suggested, please keep us posted - could be interesting.
 

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Just get some potato flakes, some water and drop a small slice of apple in. D. melanogaster are no problem. (Per another member's good advice via PM and I am editing this post to say that raising healthy fruit flies is not the goal here, but that raising "healthy frogs" is. My recipe above works for simply raising large numbers of flies, but apparently other media ingredients are necessary to make healthy flies. Still, my advice below is sound, I think.)

My thoughts after reading all this are in agreement with a few posts about:

1. culture being so wet it drowns the flies
2. flies are too old when being seeded from other cultures (along with perhaps not enough flies being introduced into the new culture)

We've all raised fruit flies a billion times. It's time to toss out that media that isn't working for you. Don't be afraid of a little mold from time to time. Spoon out the first few bits of mold. The main trick with fruit flies is adding enough of them right off the bat, to where they will lay eggs like crazy and the media will be so writhing with maggots so quickly that mold won't get a decent start!
 

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Discussion Starter · #11 ·
OK, so I've used clean containers and lids and the fly's are still dying off within a day, and all of them are dead within 2 days. I'm using fly's from fresh cultures. The media is not too wet. I'm using R.O. water. i have been sterilizing the media and excelsior and the containers and lids in the microwave to eliminate any possible microbes or any other pathogens. I just really need to figure out why the fly's are dying right away once put into those containers. i've even increased air flow to the cultures by adding tiny holes in the mesh lid. I'm at a loss for ideas right now and that's why i'm hear. Is vinegar essential to add to the media for fly production? Is bakers yeast imperative? I thought those per the possible causes for the demise of my flies, but even eliminating them hasn't helped. Thanks!
 

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At this point, I think you need to set up a few controls to isolate the troublesome variable.

It may not be healthy for your frogs, but I think you need to set up a few test cultures using a variety of recipes. For one, you might try placing some of these flies in a container with a slice of apple and see how long they live. It may prove nothing, but it might make you feel like a success for a moment!

Personally, I like to use potato flakes as a base, though I sometimes use corn flour "masa" or a mix of both.

The simple recipe for success is raising flies is potato flakes and water. If you add a spoonful of larvae into the media from a pre-existing culture, as another member suggested, you will be off to a good start as this deters mold from forming through their "turning" of the media as they eat through it. Adding more than 30 flies is recommended, though more is better.

When my cultures are slow to start, I often add a small slice of apple. This gets the flies excited in lieu of yeast, which provides the "rotting fruit" cue that attracts flies. D. melanogaster are fine with yeast, but I've had less success using it with D. hydei than the "wait and fruit" method. D. hydei appear to hold on to their eggs if the media is less than perfect sometimes.

I do often mix in a bit of vinegar, or even red wine...just a teaspoon or so (melanogaster only). If I eat some applesauce or drink a bottle of juice, the unwashed vessel will often become a new culture of flies!

None of this is a perfect method in preventing mold. I don't worry about spooning out a bit of mold if it appears and usually drop a bit of fruit in at this time if the culture seems slow to start.

Raising fruit flies is a science for many people with their old or new recipes, but it sounds like you might benefit from setting up a few cultures and playing around with them. Of course, I will mention again that what I raise flies for is mantises, young tarantulas and other spiders and various other predatory pet bugs. Your feeders are intended for frogs with apparent nutrition requirements that extend beyond what nature's fruit flies probably provide. I must imagine that the frogs eat a real variety of bugs in nature and glean the necessary nutrients from these bugs that feed on various foods. Lastly, if you take anything from what I've written, test out a few different recipes with a lot of cultures. Drop in a small bit of fruit if you don't see larval production after 7 days. It works well enough for me.
 

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At this point, I think you need to set up a few controls to isolate the troublesome variable.
I think disinfection is the first step... and then microwaving the potential culture to sterilize is the next step.

It may not be healthy for your frogs, but I think you need to set up a few test cultures using a variety of recipes. For one, you might try placing some of these flies in a container with a slice of apple and see how long they live. It may prove nothing, but it might make you feel like a success for a moment!
Life span of the flies is under genetic control and depending on the method used in culturing the flies results in differing lifespans. And the only way to get a handle on this would require only using the youngest flies from each emergence.

When my cultures are slow to start, I often add a small slice of apple. This gets the flies excited in lieu of yeast, which provides the "rotting fruit" cue that attracts flies. D. melanogaster are fine with yeast, but I've had less success using it with D. hydei than the "wait and fruit" method. D. hydei appear to hold on to their eggs if the media is less than perfect sometimes.


Actually the decomposing fruit is not the cue... it is the yeast and microbes they carry on thier bodies eventually growing on the fruit that triggers the flies to oviposit eggs. This can be done in a much more controlled manner using activated baker's yeast. If you are attempting to control for contaminents why add another item that could be a source?


Your feeders are intended for frogs with apparent nutrition requirements that extend beyond what nature's fruit flies probably provide. I must imagine that the frogs eat a real variety of bugs in nature and glean the necessary nutrients from these bugs that feed on various foods. Lastly, if you take anything from what I've written, test out a few different recipes with a lot of cultures. Drop in a small bit of fruit if you don't see larval production after 7 days. It works well enough for me.
Actually the media you use is known to produce deficient dropsphila.. one example is that the level of carotenoids in the media results in flies that can't see well.... or are effectively blind. This doesn't matter in a culture as they can sense vibrations and odors...
 

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OK, so I've used clean containers and lids and the fly's are still dying off within a day, and all of them are dead within 2 days. I'm using fly's from fresh cultures. The media is not too wet. I'm using R.O. water. i have been sterilizing the media and excelsior and the containers and lids in the microwave to eliminate any possible microbes or any other pathogens. I just really need to figure out why the fly's are dying right away once put into those containers. i've even increased air flow to the cultures by adding tiny holes in the mesh lid. I'm at a loss for ideas right now and that's why i'm hear. Is vinegar essential to add to the media for fly production? Is bakers yeast imperative? I thought those per the possible causes for the demise of my flies, but even eliminating them hasn't helped. Thanks!
Are you or are you not seeing larva in the cultures after the adults die. I think I asked this before but haven't' seen an answer yet...
 

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It seems you’ve gone to sufficient lengths to sterilize your media, but you must try again. I agree with Ed that a first, practical step is sterilization. You have proven, popular, healthy media already. His recommendation to use the youngest flies is a good one. These are the pale ones whose skins/exoskeletons have not yet hardened (for those who may later come to this thread). They can begin laying eggs in 12 hours, according to one internet reference. However, rather than picking out the youngest flies, it is standard practice to dump in a bunch of flies. Statistically, you will have a mix of ages among your chosen flies and do just fine.

As for “cues”, I’m not seeing any yeast or microbe-laden flies reproducing on my kitchen countertop. Leave an apple on that same surface however and flies will both appear and reproduce! In a culture with limited reproduction, the addition of a bit of fruit can move things along if nothing is happening, but then getting them to live more than 24 hours is the point of this discussion. Ed’s suggestion for using young flies on a sterile medium is simple and best.

Couple problems with Ed’s points, but they are no problems of mine and I prompted him with slightly off-topic points in the first place (if in the spirit of discussion and good intentions). I trust that a few more culture attempts will produce better results. I hardly pay attention to what I’m making cultures out of after many years of doing it with results exceeding my own needs.

I do hope this discussion helps. Please let us know how your flies do in the next round.
 

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Discussion Starter · #16 ·
Thankyou both, I appreciate the responses and have been running different tests as to what works and have been trying to narrow down the issue at hand as now some cultures are not just dropping dead within a day or two of introducing them. Ed in regards to the cultures where the fly's drop dead, there is no larval development and the fly's I've been using are young and have been gotten from freshly purchased cultures. I'm going to sterilize the containers in a fashion that there will be no way harmful microbes can affect the fly's despite the fact that the containers are now new. I thought microwaving 3 cultures for 6 minutes in the micro to the point where they are boiling and steamed out hard would be plenty, but a bleach rinse will be implemented prior to that. Thanks again, and I will report back with my findings! I will try the piece of fresh fruit idea as I have seen fly's reproducing in enclosures where a chunk of banana is placed in a solo cup and larvae are all over the fruit. ;)
 

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The reason I asked about the larva is because if you are using only flies from the first emergence then you are selecting for several things, one of which is a shorter lifespan, the other main one is that the flies are intolerant of certain conditions in the culture.

Part of your problem if you are using newly emerged flies is that you are using flies before they are old enough to breed or deposit eggs. If you are culturing hydei you are also using only one sex as the males emerge before the females do.. In melanogaster, using only the first emergence flies also selects for females that do not lay eggs until later than the slower and later emerging females...

Ed
 

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you might have mites, they can destroy a melanogastor culture. i put my cultures on a paper towel sprayed with mite off and they have been doing great. try some hydei cultures they are not affected by mites, or so i've read.
 

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Discussion Starter · #19 ·
I just ordered some new cups and cloth lids and I will try again with them, but I am still having problems with the fly's dying overnight after I put them into the containers. I have used all aged fly's, and a mix of ages, but still get deaths, and no larvae develop after time as i don't believe the fly's live long enough to deposit many eggs. I will throw a piece of fruit in one of the cups with the fly's to see if they will die with just that and no medium. I don't think it's the medium as I've tried several different types with the same results.
 
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