Found this on flower Bush.....wasn't there other day as I look at the mantis hunting in same plant every day.

https://en.wikipedia.org/wiki/Andricus_lignicola

Andricus lignicola
The gall wasp Andricus lignicola lays eggs into the leaf axil buds and terminal buds of English Oak and Sessile Oak causing scaly, marble like galls to form. These are often referred to as Cola-nut Galls. The galls are seen more often than the adult wasps.

At least it looks similar but could be something else

Could be a mantis nest

Google it

Ah ah.........my guess is you are correct........as I said there is a mantis thats been in the bush for weeks now.........dunno how it catches anything to eat cause not many flowers attracting wasps at the moment......certainly an odd thing that literally appeared overnight, about size of a Walnut.

You can see the drenching she got....lost a leg!!

Hi wellinever
Out of 16 photos I took this and my previous are the only 2 in focus
I was using a a slow focusing autofocus camera on a very windy day
The action was done and dusted in less than a day so if you want to catch the action be well prepared.

Tnks for that. The Mantis had gone awol for a couple of days, I reckon the downpours of the last 3 days washed it off the bush.
Are there any signs at all that they might emerge??

Where the hell do they all go after hatching?? I understand the females generally cant fly due to weight.

Can't answer that, my one and only experience

I had seen the nest for a few days but had no idea what it was

Day after the hatching there was no sign of them

Its a mantis egg sack, it will have been there a few weeks, the mantis first instars have hatched.

After losing a leg she moved to a wooden fence..no flowers for prey !
So I moved a flower head to close by her.and voila....within 3 mins a bee of some sort came down and hovered above her head.....quick as a flash she caught it and simply ate it withn a few minutes !!!
Feel a bit guilty now, fed the mantis but killed the bee !!!
Oh well here is a pic