Oaks and wasps?

[ina]

I have a kind of bonsai oak in a large container - long story, it was left from a browsing trial with deer many years ago, so it'll never grow very large... Anyway, this year I have noticed lots of wasps on the leaves all summer; they seem to be picking up something off the leaves - any idea what that could be? Maybe some tiny bug that I can't see without a magnifying glass? There's other flying insects, too, but mainly wasps. They've not at all been aggressive, though; the tree is just next to my only seat in the afternoon sun, so I've been sitting right next to it all, having a cuppa, quite a few times without them showing any interest.

[MKG]

Ordinary wasps?

If not, they could be oak gall wasps and, if they are, they should be laying their eggs on the leaves.

But if they're the stripey, stingy ones, I haven't go the foggiest idea

[diggernotdreamer]

Wasps eat all kinds of bugs, people don't realise that without wasps we would be sinking in blue bottles. They eat the cabbage white caterpillers and lots of flys, so it may be they were doing you a favour. Gall wasps don't look like regular wasps, more like thin flies

[ina]

Ordinary wasps, I'm sure. No, I wasn't trying to get rid of them - I'm sure they fulfill some kind of purpose, even if it's not that obvious to me.,. I didn't know about the cabbage white caterpillars, for example - that makes them even more welcome in my garden! :)

[doofaloofa]

i have noticed a lot of wasps around some vilimris willow

the willows also have large aphids feeding on them

i assume the wasps are milking them for honey dew

Adult wasps eats a sugary secreation produced by the wasp larva, which themselves feed on the grubs and other invertibrates the adults hunt for. At the end of the season, when no grubs remain, the adults that are left seek out alternative sources of sugars, such as jam, or in this case aphid honey dew

does your oak have aphids?

[ina]

I suspected something like this - but I've never seen any aphids! Maybe I should put my reading glasses on next time I have a closer look.