I’ve got lots of parasitic wasps making themselves comfortable on my balcony.
NOPE, not in the 5 star insect hotel I crafted JUST FOR THEM 😤
Last year, I removed a few screws I had drilled into the (gypsum?) wall, but was too lazy to also remove the hollow-core wall plugs and fix them.
Some wild wasps saw the opportunity and moved in, taking the burden off my shoulders to do the job 🤷
Now, I’d like to restore the wall to its old glory, before my landlord catches me doing stupid things 👀
But also absolutely don’t want to harm any innocent bees or other friendly critters. I want them to move out when they’re ready.
I also think many just didn’t make it, but I don’t know how to check that.
When would it be the best time of the season to seal them off?
I think the earlier you remove those holes the better for the wasps. Alternatively the holes should be empty some time in the spring.
These wasps will not stop filling holes and the last brood of the year will only hatch in the spring. After which female wasps will shortly start to fill the holes again, so there is never really a “good” time to do it. Spring after hatching would do the least damage. But there certainly is a “bad” time": You do not want to destroy the last brood of the year, that would more strongly impact the population than doing it while the female is still alive and can lay eggs in other holes.
Btw. that Insect Hotel is doing nothing for those wasps, because it will only house bees and wasps that lay their eggs into woody material. If you want to create a place where your specific parasitic wasps can flourish you need to have a hotel with dried clay with holes in it or even fired clay with holes. Because those species specialize in laying into specific materials.
Btw. remember to brush out all the holes or renew the papyrus-pipes in spring.