Colin Varndell / Knopper gall of the gall wasp (Andricus quercuscalicis) Dorset, England, UK, September.

Colin Varndell / Gall on oak acorn made by larva of Knopper gall wasp (Andricus quercuscalicis), Dorset, UK, August.

Chris Mattison / Knopper Oak gall remains, caused by the wasp (Andricus quercuscalicis) Forest of Dean, Gloucestershire, UK May

Solvin Zankl / Knopper gall (Andricus quercuscalicis) on oak tree acorn, and Common spangle gall (Neuroterus quercusbaccarum) on oak tree leaf. Bavaria, Germany

Colin Varndell / Artichoke galls (Andricus fecundator) on Pedunculate oak. Dorset, UK, August.

Kim Taylor / Oak marble-galls caused by Gall wasp (Andricus kollari). Surrey, England, September.

John Abbott / Oak Gall wasp (Andricus quercusflocci) gall, Brackenridge Field Laboratory, Austin, Travis County, Texas, USA.

Paul Harcourt Davies / Medusa's Head Gall (Andricus caputmedusae) an oak gall caused by a small wasp of the Cynipidae family. Montecucco, Orvieto, Umbria, Italy, September.

Paul Harcourt Davies / Oak Gall caused by Gall wasp (Andricus quercustozae) Podere Montecucco, Orvieto, Umbria, Italy, September.

Paul Harcourt Davies / Purplish brown, sticky oak gall caused by Gall wasp (Andricus dentimitratus) Podere Montecucco, Orvieto, Umbria, Italy, September.

Adrian Davies / Knopper galls on English oak (Quercus robur) acorns, Knopper galls are chemically induced distortions caused by gall wasps (Andricus quercuscalicis) laying eggs in the acorn buds, Surrey, England, UK,...

Ross Hoddinott / Marble galls of Oak marble gall wasp (Andricus kollari) on twig of English oak (Quercus robur). Broxwater, Cornwall, UK, August

Andy Sands / Oak marble gall wasp (Andricus kollari) on oak bud, early spring, Captive, UK

Andy Sands / Oak marble gall wasp (Andricus kollari) on oak bud, early spring, Captive, UK

Andy Sands / Oak marble gall wasp (Andricus kollari) about to take flight from oak bud, early spring, Captive, UK

Chris O'Reilly / Artichoke gall {Andricus fecundator} on Oak tree, Derbyshire, UK

Chris O'Reilly / Artichoke gall {Andricus fecundator} on Oak tree, Derbyshire, UK

Kim Taylor / Oak marble gall section showing larva of gall wasp {Andricus kollari} UK.

Kim Taylor / Oak marble gall section showing larva of gall wasp {Andricus kollari} UK.

Kim Taylor / Oak Marble Gall Wasp (Andricus kollari) cleans its wings after emerging from gall

Kim Taylor / Larva of Oak Marble Gall wasp (Andricus kollari) in gall, cross-section, UK.

Chris O'Reilly / Gall on oak acorn made by larva of Knopper gall wasp, UK

Duncan Mcewan / Artichoke galls on oak buds caused by gall wasp (Andricus fecundator), September. UK, Europe

Andy Sands / A recently emerged, Oak marble gall wasp (Andricus kollari) female grooming herself. Then the animal begins ovipositing in a bud of a Turkey oak (Quercus cerris). Hertfordshire, England, UK. March.

Andy Sands / A recently emerged, Oak marble gall wasp (Andricus kollari) female ovipositing in a bud of a Turkey oak (Quercus cerris). Hertfordshire, England, UK. March.

Linda Pitkin / Common oak (Quercus robur) acorns with Knopper galls, caused by Knopper gall wasp (Andricus quercuscalicis). Surrey, UK. August.

Linda Pitkin / Common oak (Quercus robur) with Oak marble galls, caused by Oak marble gall wasp (Andricus kollari). Howell Hill Nature Reserve, Surrey, UK. August.

Linda Pitkin / Common oak (Quercus robur) with Oak marble galls, caused by Oak marble gall wasp (Andricus kollari). Kent, UK. August.

Andy Sands / Marble Gall wasp (Andricus kollari) female ovipositing into bud of Turkey oak tree, the offspring will go on to produce the marble oak gall on Sessile oak, Hertfordshire, England, UK, March.

Andy Sands / Knopper Gall wasp (Andricus querecuscalicis) newly emerged adult on bud of turkey oak, this wasp lays eggs in early spring among the buds of Turkey Oak then the offspring lay on Pendunculate Oak to pr...

Andy Sands / Ramshorn gall wasp (Andricus aries) female died in position after ovipositing into turkey oak bud in spring, London, England, UK, February Focus Stacked.

Will Watson / Knopper galls on English Oak (Quercus robur), caused by the gall wasp (Andricus quercuscalicis), hedgerow, Worcestershire, England, August.