A question we all ask at some point when we are keeping isopods is 'what are the flying things in my isopod enclosure' or 'how do i get rid of the flying things in my tanks'.
Over the course of keeping isopods for around 5 years now, I have had issues with fungas gnats a few times. It is almost impossible to never had an issue at some point with these critters as they are attracted to the same conditions that isopods thrive in such as high humidity, decomposing organic matter and most soil and substrate.
The adult gnats are drawn in by the humid enviornment to lay their eggs then the larvae (babies) feed on the leftover isopod food and decaying plant matter.
It may not seen like much when you see a few knats but considering that females lay anywhere between 10-40 eggs every 7-10 days (laying upto 300 eggs in a lifetime) it is important to remove/destroy the gnats as you see them as well as removing areas of larvae where possible. Especially given that adult funas gnats (flying stage) lay eggs withing 1-2 days of emerging from pupae stage.
After trying many ways to resolve this issue over the years including drying enclosures up, free standing fly zappers, fly paper hanging from light fittings, I wanted to share with you all the way that I got rid of my last outbreak very quickly and then keep it manageable now very easily.
The only thing you need to buy here is a electric fly swatter which is rechargeable, this is the one i purchased https://www.amazon.co.uk/dp/B0DLK3MDKD?ref=ppx_pop_mob_ap_share&th=1 These are relatively cheap and given they are rechargeable you don't even have to replace batteries on these.
Once your swatter arrives, I used mine right out of the box, it came with almost full charge which was ideal and what I did was open a tub of isopods that was effected and turn the swatter on and rest it over the top of the tub, ideally in low light. the gnats will swarm to it and you will hear a zapping noise everytime a fly is hit (killed). One question you may have here now is 'will this not electrocute my isopods' - short answer NO it won't. The reason been, fungas gnats don't hold an electric charge theirfore as soon as they leave the swatter they are safe for the isopods to eat.
Once you have left the swatter and theres not zapping noises then then tap the tub, this usuallly encourages the remaining fungas knats to move. Once this stops, move onto the next tub until you are done then sit this swatter on the stand/holder supplier and leave it in the room near the tubs. It is best to do this when the room is dark if possible - you can also charge the swatter via the stand too.
You want to repeat this once a week until you are no longer hearing any zapping noises. Then going forward keep this swatter by you when doing isopod maintenance just incase once every few weeks.
One of the reason fungas gnats lay so many eggs so often is they have a lot of predators in the wild, one of which you wouldn't believe are isopods! So by killing off the adults you are helping distrupt the breeding/lifecycle and then the isopods will ehlp get rid of the rest. The smaller isopods usually eat the larvae if they come across them however larger, more protein hungry isopods are more likley to actively hunt and eat the soft-bodied larvae. Isopods may also eat the eggs if they come across them too.
The complete lifecycle is pretty quick, been around 3-4 weeks in optimal conditions (around 75F-80F and high humidity) So although you notice htey come about very quick, don't worry the breeding cycle is quite easy to disrupt.
Eggs hatch in 4-6days
Lave stage lasts about 2-3 weeks (they go through 4 larval instars/sheds)
Pupal stage lasts 3-5 days
Adults emergy ready to mate and can begin laying eggs within 1-2 days