Culture Resurgence?

[Mime454]

Why does it seem that a lot of fruit fly cultures have 2 lives? For example, I tried to make my first culture, but put too much bakers yeast in so it it molded quickly and all of the flies died. I was dreading cleaning it up, so I just left it there. I checked it every few days, and I am quite sure that every fly was dead. Then I come back about 2 months after the deaths and it's booming again. More flies than it ever had, thousands of them(wild caught flyers for my Mendicas).

This has happened with every melano culture I've owned. All the flies die, then it gets nasty, then a few weeks later it's booming again for a short amount of time until they eat all the food.

Any idea why this happens?

 

[hierodula]

Idk, there were probably still maggots left or eggs, and they outcompeted the mold for food?

 

[Termite48]

Another thing that can happen is that is the lid you use is permeable to wild fruit flies, they will enter after things have become attractive to them and lay their eggs and you can get a whole bunch of flying fruit flies. This does happen, but it might not explain what you are seeing.

 

[garin33]

After the adults lay eggs, they only live so long and then die off. The eggs hatch, larvae grow, eventually pupate and then hatch to adults. With Hydei, it usually happens in about 3 weeks depending on temps. Mels are faster. You have wild caught flys so the lifecycle could be longer so that's why it took so long.

Also, the mold probably killed the adults off very quick but they still had time to lay eggs. Fortunately, as Heirodula mentioned, the larvae out competed the mold for food and survived and thus finished their lifecyle. I remember when I first started I bought some fruit flys from Petco and the adults died very quick and the medium looked nasty but I forgot to throw it away. It was just sitting in the garage. I happen to see it a month or so later and it was full of flys. After that, I stopped buying fruit flys from Petco and just made my own cultures and the adults now live a really long time now.

So you may want to change medium so the adults will last longer and you are not stuck waiting for the next generation with no adult flys to feed.

One other note. When in a pinch, I have occasionally had to buy fruit flys from pet stores and it has been hit or miss. Sometimes they are fine but other times the adults die right away and then I have to wait for the next hatch. Sometimes the larvae die off and never hatch. I have never had that issue with my own cultures so be careful of the pet store stuff.

 

[Malakyoma]

Another thing that can happen is that is the lid you use is permeable to wild fruit flies, they will enter after things have become attractive to them and lay their eggs and you can get a whole bunch of flying fruit flies. This does happen, but it might not explain what you are seeing.

I used coffee filter to seal the lid on some melano cultures I made out of products of a store bought culture. Hot glue all the way around no leaks, no flies in or out, and I still got flying fruit flies escaping when I opened the lid. Guess the store bought culture I got had some flight carriers in there, and some of the babies could fly. Only way I could explain it.

 

[Termite48]

The genetics of the flight-less characteristic that has been developed with some fruit fly species is not a sure fire thing that always works into the next generation. If it is a wingless fly, that is a different story. That is a good idea that you had to seal off the intrusion of the wild flies.

 

[Malakyoma]

The biggest problem I've had is if enough maggots crawl to the top of the cup they can soak through the filter. I can add another higher up the lid, but I'd really rather not. I've only had to do it once so far.