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

Gary K. Smith / Mistle thrush (Turdus viscivorus) feeding on Mistletoe berries (Viscum album), England, UK. March

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

Adrian Davies / Scarlet caterpillarclub fungus (Cordyceps militaris / Ophiocordyceps sinensis). This species parasitises caterpillars. Sussex, England, UK. October.

Alan Williams / Mistletoe (Viscum album) growing on Apple tree (Malus domestica) in orchard Cheshire, England, UK, August.

Laurie Campbell / Mistletoe (Viscum album) close-up of berries, England, December.

Laurie Campbell / Mistletoe (Viscum album) close-up of berries, England, December.

Laurie Campbell / Mistletoe (Viscum album) close-up of berries, England, December.

Laurie Campbell / Mistletoe (Viscum album) close-up of berries, England, December.

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

Paul Harcourt Davies / Berries of Yellow-berried mistletoe (Loranthus europeaus). Podere Montecucco, Umbria, Italy, February.