Solvin Zankl / Gall wasp (Cynips quercusfolii) emerging from the oak gall. Germany, October.

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

Steve Downer / Newly emerged Gall wasp (Biorhiza pallida) preening, UK, June.

Steve Downer / Newly emerged Gall wasp (Biorhiza pallida) grooming, UK, June.

Steve Downer / Gall wasp (Biorhiza pallida) emerging from a gall on an Oak (Quercus) tree, UK, June.

Robert Thompson / Spangle gall wasp (Neuroterus quercusbaccarum) galls on oak leaf, Clare Glen, County Armagh, Northern Ireland, October.

Philippe Clement / Robin's pincushion gall, caused by the gall wasp (Diplolepis rosae) on Dog rose, Luxembourg, August

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

Colin Varndell / Silk button galls on the underside of Pedunculate oak leaf (Quercus robur) caused by the Gall wasp (Neuroterus numismalis). Dorset, UK, September.

Colin Varndell / Cherry gall of the Gall wasp (Cynips quercusfolii) on the underside of Pedunculate oak leaf (Quercus robur). Dorset, UK, September.

Colin Varndell / Common spangle galls of Cynipid wasp (Neuroterus quercusbaccarum) on the underside of Pedunculate oak leaf (Quercus robur). Dorset, UK September.

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

Stephen Dalton / Oak (Quercus robur) apple/ gall caused by a small parasitic wasp, Extermadura, Spain

Nick Upton / Cherry galls caused by Gall wasp (Cynips quercusfolii) on leaves of Pedunculate / English oak (Quercus robur), GWT Lower Woods reserve, Gloucestershire, UK, September.

Solvin Zankl / Gall wasp (Cynips quercusfolii) emerging from gall in oak. Germany. October.

Solvin Zankl / Female Gall wasp (Cynips quercusfolii) emerging from the oak gall, Germany. October.

Solvin Zankl / Gall wasp (Biorhiza pallida) gall on oak tree Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, May.

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

Solvin Zankl / Oak spangle gall (Neuroterus numismalis) on oak tree leaf, Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany

Solvin Zankl / Gall wasps (Biorhiza pallida) mating as they emerge from the oak tree gall. Elbe, Germany, June.

Solvin Zankl / Common spangle gall (Neuroterus quercusbaccarum) on oak tree leaf. Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, August.

Solvin Zankl / Gall wasp (Biorhiza pallida) on oak leaf. Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, June.

Solvin Zankl / Gall wasp (Biorhiza pallida) gall on oak tree, Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, June.

Solvin Zankl / Gall wasp (Biorhiza pallida) on oak tree leaf. Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, June.

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.

Stephen Dalton / Common oak gall wasp (Cynips quercusfolii) exposed inside oak gall, UK

Paul Hobson / Oak "apples" on Oak tree leaf (Quercus sp) caused by larva of gall wasp, UK

Mark Moffett / Oriental Chestnut Gall Wasp (Dryocosmus kuriphilus) emerging from gall in acorn, Massachusetts

Robert Thompson / Oak galls made by the Oak gall wasp (Cynops divisa) on fallen oak leaves, Clare Glen, County Armagh, Northern Ireland, UK

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.

Doug Wechsler / Oak apple galls formed by Gall wasp (Amphibolips sp.) Pennsylvania, USA. May.

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.

Roland Seitre / Cherry gall (Cynips quercusfolii) on underside of oak leaf, Centre, France. October. (Cynipidae).

Alex Hyde / Galls of the Silk button gall wasp (Neuroterus numismalis) on the underside of a fallen Oak (Quercus sp.) leaf. A single adult wasp will emerge from each gall, Peak District National Park, Derbyshire,...

Alex Hyde / Galls of the Silk button gall wasp (Neuroterus numismalis) on the underside of a fallen oak leaf.Peak District National Park, Derbyshire, UK. November.

Alex Hyde / Galls of the Silk Button gall wasp (Neuroterus numismalis) on the underside of an oak leaf. A single wasp will emerge from each gall. Neuroterus numismalis has two generations per year, the first sexu...

Alex Hyde / Galls of the Silk Button gall wasp (Neuroterus numismalis) on the underside of an oak leaf. A single wasp will emerge from each gall. Neuroterus numismalis has two generations per year, the first sexu...

Guy Edwardes / Cherry gall (Diplolepis quercusfolii) on oak leaf, Rhodope Mountains, Bulgaria. November.

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.

Nick Upton / Robin's pincushion gall caused by the Bedeguar gall wasp (Diplolepis rosae) on Dog rose (Rosa canina) stem in a hedgerow, Wiltshire, UK, September.

Nick Upton / Silk Button spangle Galls / Oak spangle galls (Neuroterus numismalis) on Pedunculate / English oak (Quercus robur) leaves, GWT Lower Woods reserve, Gloucestershire, UK, October.

Nick Upton / Smooth rose pea gall caused by a Cynipid gall wasp (Diplolepis nervosa or Diplolepis eglanteriae) on Dog rose (Rosa canina) stem in a chalk grassland meadow, Wiltshire, UK, September.

Nick Upton / Smooth rose pea gall caused by a Cynipid gall wasp (Diplolepis nervosa or Diplolepis eglanteriae) on Dog rose (Rosa canina) stem in a chalk grassland meadow, Wiltshire, UK, September.

Nick Upton / Common spangle galls (Neuroterus quercusbaccarum) and Silk Button spangle Galls / Oak spangle galls (Neuroterus numismalis) on Pedunculate / English oak (Quercus robur) leaves, GWT Lower Woods reserve...

Colin Varndell / Cherry gall of the gall wasp (Cynips quercusfolii) on the underside of Pedunculate oak leaf (Quercus robur) Dorset, UK September.

Nigel Cattlin / Spangle gall wasp (Neurotus quercusbaccarum) galls on underside of Oak (Quercus robur) leaf. Berkshire, England, UK.

Nigel Cattlin / Gall of a bedeguar gall wasp (Diplolepis rosae) or robin's pincushion on the stem of a wild dog rose, Rosa, canina, Berkshire, September

Nick Upton / Robin's pincushion gall on Dog rose (Rosa canina) stem caused by the Bedeguar gall wasp (Diplolepis rosae), Wiltshire, UK, September.

Nick Upton / Robin's pincushion gall on Dog rose (Rosa canina) stem caused by the Bedeguar gall wasp (Diplolepis rosae), Wiltshire, UK, September.

Colin Varndell / Silk button galls on the underside of Pedunculate oak (Quercus robur) leaf caused by the Gall wasp (Neuroterus numismalis) Dorset, England, UK. July.

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