Egg ID ??

[Tormentil]

Are these the eggs of some insect or other. They were on the underside of an oak leaf.

[Lance Morgan]

These are Spangle Galls. They are produced by a tiny Cynipid wasp.

[Tormentil]

Thanks Lance.

[poschiavanus]

Originally Posted by Lance Morgan

These are Spangle Galls. They are produced by a tiny Cynipid wasp.

Just to add to Lance's post: these are the Silk-button Spangle gall caused by the asexual generation of Neuroterus numismalis. Here's a close-up:



There are two other common and one uncommon spangle galls. Here's the common spangle from the gallery:


Most of these galls have been uncommon to absent over the past few years: probably because of parasitoid load. Once the galls become few and far between the parasitoids themselves die out and the galls reappear.

Also common on the underside of oak leaves are the Oyster Gall Neuroterus anthracinus and the Pea Gall Cynips divisa. Like the spangles caused by tiny gall wasps.

The Hainault Forest website has a good page on Oak Galls. Hedgerowmobile has a good page on the wasps.

HTH,

poschiavanus

[Tormentil]

Thanks for the extra info poschiavanus. Much appreciated.