They occupy a very similar ecological niche, and thus compete for resources. By having a strong population of natives and EHs, the resources for AH are restricted, and makes their establishment more difficult.
These two threads are worth a read
rubbish!
Last time we had mass queen wasp die off was in 2012 and before that 2004. It's not unusual. Mild winters and inclement Springs and early Summers are very challenging for wasps. I disturbed a germanic nest in a pile of rubble whilst working on a garden project and it was at least a month behind development wise.
So a corollary from that study could be that wasps form a large proprtion of their diet, and that wasp nests act as a decoy for bees...
Thank you for this link. It's certainly an interesting paper. I don't think there are any surprises in it but it is good to see corroboration of what is generally understood of velutina's diet.
The bit that is missing is the size of the nests when sampled. A 50% wasp diet in a vastly under populated velutina nest is a good thing. It shows that velutina is struggling to find easier more abundant prey and small numbers of wasps taken don't reflect casualty rates amongst hunting velutina which creates a very positive feedback loop. The more hunting hornets that don't make it back, the more the remaining hunting hornets are forced to go for wasps the less resources get to the development of larvae and sexuals.
Thanks for the additional insights. Huge value.
Similar niche and diet, yes, but I am inclined to think that a strong population of native wasps simply provides a better buffet for AHs.
