Ammonite / Mining bee (Andrena apicata) flying and feeding from Sallow (Salix caprea) catkins, with pollen sacs on hind legs, France, March.

Andy Sands / Mining Bee (Andrena clarkella) on Sallow catkin, Hertfordshire, England, UK, March

Andy Sands / Mining Bee (Andrena clarkella) on Sallow catkin, Hertfordshire, England, UK, March

Ross Hoddinott / Pussy willow / Sallow (Salix caprea) catkins, Cornwall, UK. April .

Ross Hoddinott / Sallow / Pussy willow {Salix caprea} catkin, Cornwall. UK

WILLIAM OSBORN / Long tailed tit & sallow flowers UK

Mike Wilkes / Greenfinch on flowering sallow (Carduelis chloris) Wiltshire UK

WILLIAM OSBORN / Blue Tit portrait in spring (Parus caeruleus) Wiltshire, UK. perched in flowering sallow.

Nigel Cattlin / Goat willow (Salix caprea) male catkins. Kennett and Avon Canal, Berkshire, England, UK. April.

Will Watson / Water Hog-louse or Water Slater (Asellus aquaticus) on sallow leaf, Herefordshire Plateau, England, December 2018. Captive.

Will Watson / Water Hog-louse or Water Slater (Asellus aquaticus) with exopod regrowing, sallow leaf, captive conditions, garden pond, Herefordshire Plateau, England, December 2018.

Andy Sands / Grey willow (Salix cinerea) close up of male flowers, Hertfordshire, England, UK, April, Focus Stacked

Phil Savoie / Bumblebee mimic hoverfly (Eristalis intricarius) feeding on Grey willow (Salix cinerea) pollen, Monmouthshire, Wales, UK, April.

Russell Cooper / Honeybee (Apis mellifera) feeding from female Sallow / Goat willow catkin (Salix caprea) Southwest London, England, UK, March.

David Kjaer / Sallow kitten (Furcula furcula) moth showing mimicry as defensive strategy, Wiltshire, UK

Rod Williams / Dusky sallow moth (Eremobia ochroleuca) day-flying moth on wild marjoram, Hutchinson's Bank, New Addington, London, UK. July.

Jussi Murtosaari / Bordered sallow moth (Pyrrhia umbra) on flower, Uusimaa, Finland, July.

Adrian Davies / Puss moth (Cerura vinula) larva feeding on Sallow, Surrey, England, UK, July.

Colin Varndell / Grey willow tree (Salix cinerea), male catkins. Dorset, UK, March.

Colin Varndell / Grey willowtree (Salix cinerea), female catkin and foliage. Dorset, UK, April.

Alex Hyde / Pink-barred Sallow moth (Xanthia togata) camouflaged on a fallen oak leaf. The National Forest, Leicestershire, UK. September.

Alex Hyde / Pink-barred Sallow moth (Xanthia togata) photographed in mobile field studio on a white background. The National Forest, Leicestershire, UK. September.

Alex Hyde / Angle-striped Sallow moth (Enargia paleacea) photographed in mobile field studio on a white background. The National Forest, Leicestershire, UK. September.

Alex Hyde / Centre-barred Sallow (Atethmia centrago). Photographed in mobile field studio on a white background. Peak District National Park, Derbyshire, UK. August.

Jussi Murtosaari / Barred sallow moth (Tiliacea aurago) on oak leaf in autumn, Aland Islands, Finland, September.

Paul Hobson / The Sallow moth (Xanthia icteritia) at rest on sandstone, Sheffield, September.

Paul Hobson / Pink-barred sallow moth (Xanthia togata) resting on dead wood, Sheffield, England, UK, October.

Paul Hobson / Centre-barred Sallow (Atethmia centrago) moth, adult resting on Scots pine bark, (Pinus sylvestris) Sheffield, England, UK, August.

Andy Sands / Tree Bumblebee (Bombus hypnorum) foraging on catkins of Sallow, Hertfordshire, England, UK, March

Mark Payne-Gill / Purple Emperor Butterfly (Apatura iris) larva showing defensive camouflage effect on Sallow leaf (Salix caprea). Studio, Tetbury.

Mark Payne-Gill / Hibernating Purple Emporer Butterfly (Apatura iris) larva with snow melting on Sallow branch (Salix caprea). Studio, Tetbury.

Mark Payne-Gill / Hibernating Purple Emporer Butterfly (Apatura iris) larva with snow melting on Sallow branch (Salix caprea). Studio, Tetbury.

Mark Payne-Gill / Purple Emperor Butterfly (Apatura iris) resting on Sallow leaf (Salix caprea). Alice Holt Forest, Surrey, July.

Laurie Campbell / Goat / Pussy willow / Sallow (Salix caprea) flowers in spring, Midlothian, Scotland, April

Andy Sands / Puss Moth (Cerura vinula) pupa on Sallow twig, UK, August

Andy Sands / Puss Moth (Cerura vinula) caterpillar larva feeding on Sallow / Willow leaf, UK, July

Andy Sands / Puss Moth (Cerura vinula) caterpillar larva feeding on Sallow / Willow leaf, UK, July

Andy Sands / Puss Moth (Cerura vinula) caterpillar larva feeding on Sallow / Willow leaf, UK, July

Andy Sands / Puss Moth (Cerura vinula) caterpillar larva feeding on Sallow / Willow leaf, UK, July

Ross Hoddinott / Pussy willow / Great sallow (Salix caprea) catkins, backlit, against a black background. Broxwater, Cornwall, UK, April

Colin Varndell / Male Yellowhammer perched on branch of Sallow catkins, in breeding condition. Dorset, UK, April, 2010

Philippe Clement / Goat / Pussy willow / Great sallow branch (Salix caprea) with female catkins, Belgium

Philippe Clement / Goat / Pussy willow / Great sallow branch (Salix caprea) with male catkins, Belgium

Robert Thompson / Pink-barred sallow moth (Xanthia togata) camouflaged amongst fading / diseased leaves, Annaloughan Bog, County Tyrone, Northern Ireland, UK, August

Stephen Dalton / Sallow moth (Xanthia icteritia) at rest, UK

Andy Sands / Poplar hawkmoth (Laothoe populi) resting on Sallow / Willow twig, Hertfordshire, England, UK

Stephen Dalton / Dusky sallow moth {Eremobia ochroleuca} camouflaged against lichen, UK

Gary K. Smith / Leopard Moth {Zeuzera pyrina} at rest on Sallow branch, Norfolk, UK, July

Andy Sands / Long tailed tit (Aegithalos caudatus) perched on Sallow catkins, West Sussex, England, UK

Ross Hoddinott / Sallow / Pussy Willow {Salix caprea} catkins, North Cornwall. UK

Ross Hoddinott / Sallow {Salix caprea} catkins, Cornwall. UK

Andy Sands / Small Emerald Moth (Hemistola chrysoprasaria) At rest on Sallow leaf, Hertfordshire, UK

PREMAPHOTOS / Caterpillar larva of Sallow kitten moth (Harpyia / Furcula furcula) showing countershading, UK

PREMAPHOTOS / Caterpillar larva of Buff-tip moth (Phalera bucephala) feeding on Sallow leaf {Salix sp} UK

Simon Colmer / Goat Willow / Sallow / Pussy Willow (Salix caprea) male catkins, UK.

David Kjaer / Robin {Erithacus rubecula} perched on sallow / pussy willow {Salix caprea} springtime, Yorkshire, UK

Jose B. Ruiz / Sallow kitten moth {Furcula furcula} on branch, Spain.

Jose B. Ruiz / Sallow kitten moth {Furcula furcula} on branch, Spain.

Jose B. Ruiz / Sallow kitten moth {Furcula furcula} on branch, Spain.

Jose B. Ruiz / Sallow kitten moth {Furcula furcula} on branch, Spain.

Andy Sands / Southern hawker dragonfly {Aeshna cyanea} male resting on Sallow. UK.

Ross Hoddinott / Sallow / Pussy willow (Salix caprea) catkins Cornwall, UK

Philippe Clement / Sallow / pussy willow catkins {Salix caprea} Belgium

Paul Hobson / Sallow kitten moths mating {Cerula / Furcula furcula} Yorkshire, England

Paul Hobson / Sallow kitten moth {Cerula / Furcula furcula} Yorkshire, England

Philippe Clement / Sallow / pussy willow catkins {Salix caprea} Belgium

Ross Hoddinott / Sallow catkins / Pussy willow {Salix caprea} Cornwall, UK

Ross Hoddinott / Goat willow male catkins {Salix caprea} Cornwall, UK

Artur Tabor / Fen sallow in winter {Salix cinerea} Nadbuzanski NP, Poland

WILLIAM OSBORN / Great tit on flowering sallow tree branch UK (Parus major)

Robert Thompson / Sallow moth (Xanthia icteritia) camouflaged on leaf litter, Lackan Bog, County Down, Northern Ireland, UK, August

Robert Thompson / Sallow kitten moth (Furcula furcula) resting on branch, camouflaged against bark, County Tyrone, Northern Ireland, UK, May

Robert Thompson / Sallow kitten moth (Furcula furcula) resting on branch, camouflaged against bark, Brackagh Moss NNR, County Armagh, Northern Ireland, UK, May

Premaphotos / Wood ant (Formica rufa) tending aphid farm on a Sallow shoot, UK

Will Watson / Hybrid sallow (Salix x reichardtii) male catkins close to ripening, Bodenham Lake Nature Reserve, Herefordshire, England, UK, April.

Will Watson / Hybrid sallow (Salix x reichardtii) male catkins close to ripening, Bodenham Lake Nature Reserve, Herefordshire, England, UK, April.

Will Watson / Rusty willow (Salix cinerea oleifolia) male catkins in tormentose stage with scale buds, Eaton Wood, Herefordshire, England, UK, March. Focus stacked under controlled conditions.

Will Watson / European honeybee (Apis mellifera) worker gathering nectar from Hybrid sallow (Salix x reichardtii) male catkins, Herefordshire, England, UK, April.

Will Watson / Ice Age pond with logs from felled Sallow trees (Salix caprea) at pond's edge, felled to allow more light into pond, Staunton-on-Arrow, Herefordshire, England, UK, March.

Will Watson / Removal of Sallow (Salix caprea) trees with digger from pond edge to restore the pond, Breinton Orchard, Herefordshire Cider Museum, Herefordshire, England, UK, February.

Will Watson / Small sallow mining bee (Andrena praecox) female resting on broken branch, Stockings Meadow, Herefordshire, England, UK, April.

Will Watson / Hybrid Sallow (Salix x reichardtii) leaves - the hybrid between Goat willow and Grey sallow, Bodenham Nature Reserve, Herefordshire Widlife Trust, England, UK. June. Focus stacked.

Will Watson / Grey sallow (Salix cinerea cinerea) leaves showing white hairs, young branches and stipules, Rutland, Leicestershire, England, UK. July. Focus stacked.

Will Watson / Close up of underside of Rusty sallow (Salix cinerea subspecies oleifolia) leaf showing hairs and veins, magnified x10, River Lugg floodplain, Herefordshire, England, UK. June.

Will Watson / Rusty sallow (Salix cinerea oleifolia) leaves and stipules, River Lugg floodplain, Herefordshire, England, UK. June.

Joel Sartore / Photo Ark / Morrison's sallow moth (Eupsilia morrisoni) portrait, Deerwood, Minnesota, USA.

Joel Sartore / Photo Ark / Morrison's sallow moth (Eupsilia morrisoni) portrait, Deerwood, Minnesota, USA.

Will Watson / Grey sallow (Salix cinerea) branches covered by Beard lichen (Usnea sp.), Lochan, Darnaway Estate, Highlands, Scotland, UK. May.

Will Watson / Grey sallow (salix cinerea) trees reflectiing on an Ice Age pond, Herefordshire, England, UK. April.

Will Watson / Grey sallow (Salix cinerea) male catkins, Herefordshire, England, UK. March. Focus stacked.

Will Watson / Grey sallow (Salix cinerea) male catkins, Herefordshire, England, UK. March. Focus stacked.

Will Watson / Grey sallow (Salix cinerea) male catkins, Herefordshire, England, UK. March. Focus stacked.

Will Watson / Grey sallow (Salix cinerea) female catkins, Herefordshire, England, UK, April. Focus stacked.

Will Watson / Female Drone fly (Eristalis tenax) nectaring on Grey sallow (Salix cinerea) catkin, Herefordshire, England, UK. March.

Will Watson / Female Drone fly (Eristalis tenax) and Greater bee fly (Bombylius major) nectaring on Grey sallow (Salix cinerea) catkins, Herefordshire, England, UK. March.

Nick Upton / Pussy willow / Goat willow / Great sallow (Salix caprea) female catkins, Lower Woods, Gloucestershire, UK. April.