|Chalcicoid wasp, family Ormyridae, perhaps genus Ormyrus. West Wickham Common, 23 September 2015|
It's a little iridescent wasp. There are lots of small parasitic wasps, some of which, for example, lay their eggs in creatures that live inside oak galls. This one doesn't seem to have the right ovipositor for that sort of thing - it would be long and thin - but I don't think it's investigating this acorn in search of a nice vegetarian meal.
It's quite showy, though you can see from the size of the acorn it is walking on that it is really small.
|Acorn Weevil (probably), Curculio glandium. Curculionidae. West Wickham Common, 23 September 2015|
These weevils have very weird jointed antennae emerging part way down their proboscis. Thejoint is mobile, and the arms of the antennae can be brought back to lie parallel to and touching the proboscis.
|Araniella species. Araneidae. West Wickham Common, 23 September 2015|