Fruit fly problems with roach colonies

[SkyeSpider]

My wife and I are losing our minds on this issue.

We have multiple roach colonies: B dubia, B lataralis, hissers, dominoes, etc. The first three end up with massive fruit fly issues every summer since we moved to upstate NY.

We keep fly strips that have to be replaced constantly. I’ve tried setting the roaches up with and without substrate. I’ve done water dish and no dish. I remove their food the day after it’s given. I pick out dead roaches twice a week. Still, we have flies.

What does everyone else do with this problem? Is there a detail I’m missing?

 

[Wolfram1]

Pretty sure those are not fruit-flies but a Phoridae sp., better known as Hump-Back-Flies.

Almost impossible to get rid of completely once they have established themselves.
I got rid of mine by separating all my live roaches into a new bin, with all new interior and vacuuming any remaining flies i saw daily for about a month.

There were no other areas they could have established themselves, no reptile cages etc.

i also made my new setup almost fly proof so no new flies could get into the colony.

 

[SkyeSpider]

Pretty sure those are not fruit-flies but a Phoridae sp., better known as Hump-Back-Flies.

Almosti also made my new setup almost fly proof so no new flies could get into the colony.

Thanks for the correction. How did you make your setups fly proof? I’ve had to add quite a bit of ventilation to prevent mold. I can’t imagine sealing that up.

 

[Wolfram1]

by using 0.2mm stainless steel mesh/gaze, no flies get through that, you can use any smaller mesh size as well ofc. the only weak point is actually the lid, since it doesn't seal airtight

you can cut it to size and melt it into the plastic using a soldering iron or similar tools that use heat for drawing on wood.

i posted a picture of my current setup some time ago: https://arachnoboards.com/threads/bit-the-bullet.353410/post-3266923

sadly it is not the best quality, but you can see the mesh & method i used in this picture better here, though this is the 0.1mm version of the mesh: https://arachnoboards.com/attachments/img_20220205_030710-jpg.409958/

i use it for all my ventilation needs

 

[Smotzer]

They also could simply be fungus gnats

 

[SkyeSpider]

They also could simply be fungus gnats

And what do you recommend if it’s them?

 

[The Snark]

Build a simple cage out of 1/8th to 1/4th inch hardware cloth. Suspend above your roaches in the middle of their containment. Install a couple of geckos in the cage.

 

[Smotzer]

And what do you recommend if it’s them?

Mosquito dunks/bits and sticky traps! And micro mesh

 

[Wolfram1]

The traps help but if they are indeed a Phoridae sp. then you will not be able to rid yourself of them completely without drastik measures.

I forgot to mention i also reduced feedings to a bare minimum to encurage them to clean up any of their own dead and left out any protein rich foods for the duration of a few months.

Dogfood, catfood, fishflakes, etc. can also be used as a breeding ground.

They can also lay eggs on any injured animals and the larvae will eat them alive.


If you are having a problem with a Sciaridae sp. (fungus gnats), that is a seperate issue as they do not rely on animal carcases and instead feed on plant roots, and other organic matter inside the soil of invert cages or potted house plants.

I was not able to get rid of these permanently so far but they are a lesser evil.

Sealing any bins, enclosures etc. for these pests is defenitly a step that helps ether way however. I honestly wonder why most people don't bother. There is nothing worse than preparing a cup of tee or coffee only to end up with a fly in it.

here is my B. latteralis colony, i set it up with the flies in mind from the start and never had any pests in this one. It is a little neglected as i was not planning to have them long term and needs to be cleaned soon:

https://arachnoboards.com/attachments/img_20220506_194739-jpg.417562/

Good luck to you.