Phil Savoie / Painted nomad bee (Nomada fucata) male bee with characteristic green eyes, sleeping with jaws locked around grass stem, Monmouthshire, Wales, UK. June

Laurent Geslin / Vestal cuckoo bee in flight, Europe

Phil Savoie / Painted nomad bee (Nomada fucata) male with characteristic green eyes, feeding on Dandelion (Taraxacum offinicale) Monmouthshire, Wales, UK. April

Phil Savoie / Painted nomad bee (Nomada fucata) male with characteristic green eyes, sleeping with jaws locked onto grass blade, Monmouthshire, Wales, UK. April

Phil Savoie / Painted nomad bee (Nomada fucata) female, kleptoparasite outside the nest burrow of Yellow legged mining bee (Andrena flavipes) where it will kill the larvae in the burrow before laying its own eggs w...

Phil Savoie / Painted nomad bee (Nomada fucata) female laying eggs in the nest burrow of Yellow legged mining bee (Andrena flavipes) larva kleptoparasitises pollen store of Andrena flavipes larve killing them, Rive...

Oliver Wright / Cuckoo bee (Nomada sp) resting on leaf. Fairburn Ings RSPB nature reserve, West Yorkshire, England, UK. May. Focus stacked image.

Clay Bolt / Neon cuckoo bee (Thyreus sp). Ternate, North Maluku, Indonesia.

Phil Savoie / Painted nomad bee (Nomada fucata) female inspecting Yellow legged mining bee (Andrena flavipes) nest burrows to lay eggs in. Monmouthshire, Wales, UK, April.

Phil Savoie / Painted nomad bee (Nomada fucata) female, kleptoparasite of Yellow legged mining bee (Andrena flavipes), inspecting nests to lay eggs in. Monmouthshire, Wales, UK. April.

Phil Savoie / Painted nomad bee (Nomada fucata) feeding on Dandelion (Taraxacum officinale) male animal with characteristic green eyes, Monmouthshire, Wales, UK. April.

Phil Savoie / Painted nomad bee (Nomada fucata) male with characteristics green eyes, feeding on Dandelion (Taraxacum offinicale) Monmouthshire, Wales, UK. April

Andy Sands / Resin Bee (Heriades truncorum) sealing the end of a nesting tube in a garden Bee hotel with resin, Hertfordshire, England, UK, June

Andy Sands / Resin bee (Heriades truncorum) this small Bee uses resin to seal her nest cells until recently a rare species of lowland heath they can now be found nesting in garden bee hotels across southern Englan...

Andy Sands / Resin Bee (Heriades truncorum) In flight approaching garden bee hotel the distinctive yellow pollen brush is clearly visible, Hertfordshire, England, UK, June

Kim Taylor / Cuckoo bee (Nomada ruficornis) entering burrow of Mining Bee (Andrena bimaculata). Surrey, England,

Will Watson / Male Field Cuckoo Bumblebee (Bombus campestris) on Spear Thistle (Cirsium vulgare), Herefordshire Plateau, England, UK, August.

Phil Savoie / Nomad bee (Nomada flava) Monmouthshire, Wales UK, May.

Phil Savoie / Field cuckoo bee (Bombus campestris) feeding on Toadflax (Linaria purpurea) Monmouthshire, Wales, UK. June.

Rod Williams / Vestal cuckoo bee (Bombus vestalis) on red clover, Hutchinson's Bank, New Addington, London, England, UK. July.

Phil Savoie / Field cuckoo bumblebee (Bombus campestris) feeding on Goldenrod (Solidago). Monmouthshire, Wales, UK. September.

Will Watson / Gooden's nomad bee (Nomada gooeniana) on Great forget-me-not, (Brunnera macrophylla) in garden, Herefordshire Plateau, England, UK, May.

Andy Sands / Sharp-tail Bee (Coelioxys elongata) male feeding on nectar from Fleabane flower, Oxfordshire, England, UK, August

Andy Sands / Sharp-tail Bee (Coelioxys elongata) male feeding on nectar from Fleabane flower, Oxfordshire, England, UK, August

Andy Sands / Sharp-tail Bee (Coelioxys elongata) male feeding on nectar from Fleabane flower, Oxfordshire, England, UK, August

Steve Gettle / Brown-belted Bumblebee (Bombus griseocollis) and Lemon Cuckoo Bumblebee (Bombus citrinus) feeding on flower nectar, Howell Nature Center, Michigan

MYN / Clay Bolt / Lemon cuckoo bumblebee (Bombus citrinus) cleptoparasitic species, Dacusville, South Carolina, USA. Meetyourneighbours.net project

MYN / Clay Bolt / Lemon cuckoo bumblebee (Bombus citrinus) cleptoparasitic species, Dacusville, South Carolina, USA. Meetyourneighbours.net project

MYN / Clay Bolt / Lemon cuckoo bumblebee (Bombus citrinus) cleptoparasitic species, Dacusville, South Carolina, USA. Meetyourneighbours.net project

MYN / Clay Bolt / Lemon cuckoo bumblebee (Bombus citrinus) cleptoparasitic species, Dacusville, South Carolina, USA. Meetyourneighbours.net project

MYN / Clay Bolt / Lemon cuckoo bumblebee (Bombus citrinus) cleptoparasitic species, Dacusville, South Carolina, USA. Meetyourneighbours.net project

Clay Bolt / Cuckoo Bee (Holcopasites calliopsidis) with US dime, to show small size. South Carolina, USA, May. Meetyourneighbours.net project

MYN / Clay Bolt / Eastern carpenter bee (Xylocopa virginica) with high density of mites, next to a Cuckoo bee (Holcopasites calliopsidis), which is dwarfed by a US dime. Composite. Meetyourneighbours.net project

MYN / Clay Bolt / Leafcutter cuckoo bee (Coelioxys sp), Pickens, South Carolina Meetyourneighbours.net project

MYN / Clay Bolt / Cuckoo Bee (Nomada sp, Ruficornis group), male, South Carolina, USA Meetyourneighbours.net project

MYN / Clay Bolt / Cuckoo bee (Sphecodes sp) South Carolina, USA, March. Meetyourneighbours.net project

MYN / Clay Bolt / Cuckoo bee (Nomada sp), Madison, Wisconsin, USA, September. Meetyourneighbours.net project

MYN / Clay Bolt / Cuckoo bee (Triepeolus sp) Madison, Wisconsin, USA. September. Meetyourneighbours.net project

MYN / Clay Bolt / Cuckoo bee (Triepeolus sp) Madison, Wisconsin, USA.September. Meetyourneighbours.net project

Clay Bolt / Lemon cuckoo bumblebee (Bombus citrinus) queen on Russian sage, Madison, Wisconsin, USA, August.

Will Watson / Field Cuckoo bumblebee (Bombus campestris) on Spear thistle (Cirsium vulgare), Herefordshire, England.

Will Watson / Red-tailed Cuckoo Bumblebee (Bombus rupestris) pollinating Marjorum (Origanum sp.), Tenbury Wells, Worcestershire, England.

Will Watson / Male Forest Cuckoo Bumbelbee (Bombus sylvestris), garden, Herefordshire, England.

Will Watson / Two male Forest Cuckoo Bumblebees (Bombus syvestris) on Perennial Cornflower (Centaurea montana), garden, Herefordshire, England.

Will Watson / Vestal Bumblebee (Bombus vestalis) on Bramble (Rubus fruticosus. agg), Bockleton Churchyard, Worcestershire, England.

Will Watson / Male Forest Cuckoo Bumblebee (Bombus sylvestris) on Ivy (Hedera helix), Herefordshire, England.

Alan Williams / Nomad Bee (Nomada sp) resting on leaf at woodland edge Cheshire, UK, May.

Alan Williams / Bee (Coelioxys conoidea) female feeding on Common Fleabane (Pulicaria dysenterica) flower Cheshire, UK, August.

Roger Powell / Pheasant coucal (Centropus phasianus) with a bee in its beak. Mary River Park, Northern Territory, Australia.

Rod Williams / Gooden's nomad bee (Nomada goodeniana) On privet Brockley , Lewisham, London. April.

Andy Sands / Cuckoo bee / Nomad bee (Nomada fucata) cuckoo bee in the nests of Andrena flavipes, Surrey, England, UK. July

Andy Sands / Sharp-tailed bee (Coelioxys conoidea) cleptoparasite of Leaf cutter bee (Megachile maratima) these bees use their sharp tail to slice into the nest of the host leaf cutter bee to lay their eggs inside...

Andy Sands / Gooden's nomad bee (Nomada goodeniana) a cuckoo bee that lays her eggs in the nests of various large Andrena bees, Hertfordshire, England, UK. April

Andy Sands / Cuckoo bee / Nomad bee (Nomada flava) cuckoo bee who lays her eggs in the nests of various andrena bees, Hertfordshire, England, UK, May

Andy Sands / Sharp-tailed bee (Coelioxys conoidea) cleptoparasite of Leaf cutter bee (Megachile maritima). This species uses their sharp tails to slice into the nests of the host leaf cutter bees to lay their egg...

Andy Sands / Cuckoo bee/ Nomad bee (Nomada fucata) about to go into nest of Mining bee (Andrena flavipes) Surrey, England, UK. July

Andy Sands / Cuckoo bee / Nomad Bee (Nomada fabriciana) cuckoo bee in the nests of Andrena bicolor, Hertfordshire, England, UK. April

Stephen Dalton / Field cuckoo bee (Bombus campestris) on flower, Sussex, UK

Will Watson / Vestal cuckoo bumblebee (Bombus vestalis) feeding on Purple Cranesbill (Geranium x magnificum) Herefordshire, England, UK, June.

Will Watson / Vestal cuckoo bumblebee (Bombus vestalis) feeding on White clover (Trifolium repens) on garden lawn, Herefordshire, England, UK, June.

Will Watson / Vestal cuckoo bumblebee (Bombus vestalis) feeding on Knapweed (Centaurea nigra), Herefordshire, England, UK, June.

Will Watson / Vestal Bumblebee (Bombus vestalis) on Purple Geranium (Geranium x magnificum), garden border, Herefordshire, England.

MYN / Corne van der Linden / Cuckoo bee (Thyreus waroonensis) South-Western Australia. November.

Alex Hyde / Cuckoo bee (Nomada leucophthalma) about to enter the nest burrow of Miner Bee (Andrena clarkella). The cuckoo bee is cleptoparasitic, laying its eggs in nests of other bees in order that their parasit...

Alex Hyde / Cuckoo bee (Sphecodes sp.) female, Peak District National Park, Derbyshire, UK. April.

MYN / Gil Wizen / Cuckoo bee (Thyreus sp) a cleptoparasite of other species of bees, Central Coastal Plain, Israel, June. meetyourneighbours.net project

MYN / Gil Wizen / Cuckoo bee (Thyreus sp) a cleptoparasite of other species of bees, Central Coastal Plain, Israel, June. meetyourneighbours.net project

Andy Sands / Cuckoo bee (Sphecodes) Berkshire, England, UK. April

Andy Sands / Cuckoo bee (Sphecodes) Berkshire, England, UK. April

Andy Sands / Cuckoo bee (Nomada) female about to enter the burrow of Mining bee (Andrena haemorrhoa) Hertfordshire, England, UK. May

Andy Sands / Bee (Epeolus cruciger) cleptoparasite of Colletes succinctus, resting on a Bell heather flower. It is covered in sand from where it recently entered the burrow of it's host, Surrey, England, UK. Augus...

Andy Sands / Bee (Epeolus cruciger) cleptoparasite of Colletes succinctus, resting on a Bell heather flower. It is covered in sand from where it recently entered the burrow of it's host, Surrey, England, UK. Augus...

John Abbott / Indiscriminate Cuckoo Bumble Bee (Bombus insularis) Inyo National Forest, Mono County, California, USA, June.

MYN / Clay Bolt / Cuckoo Bee (Nomada) sleeping on twig, Southern Appalachians, South Carolina, United States, April. Meetyourneighbours.net project

MYN / Clay Bolt / Cuckoo Bee (Nomada) sleeping, Southern Appalachians, South Carolina, United States, April. Meetyourneighbours.net project

Phil Savoie / Forest cuckoo bumblebee (Bombus sylvestris) male in flight towards flowers (Brachyglottis). This species is parasitic in Early bumblebee nests. Monmouthshire, Wales, UK, June.

Phil Savoie / Forest cuckoo bumblebee (Bombus sylvestris) male feeding on flowers (Brachyglottis). This species is parasitic in Early bumblebee nests. Monmouthshire, Wales, UK, June.

Ammonite / Nomad bee (Nomada flava) feeding on Forget-me-not nectar, in urban garden, Bristol, UK, June.

Ammonite / Marsham's Nomad Bee (Nomada marshamella) feeding on Forget-me-not nectar, in urban garden, Bristol, UK, June.

Rod Williams / Vestal cuckoo bee (Bombus vestalis) on flower, Brockley Cemetery, Lewisham, UK, August.

Michael Durham / Male Cuckoo bee (Thyreus sp possibly T. histrionicus) in flight, Matobo National Park , Zimbabwe, November.

Rod Williams / Cuckoo Bee (Bombus vestalis) covered in pollen, on thistle, Lewisham, London, July

Andy Sands / Cuckoo bee (Melecta albifrons) parasite of (Anthophora plumipes) on old wall where host species nests, Hertfordshire, England, UK, April

Andy Sands / Cuckoo bee (Melecta albifrons) parasite of (Anthophora plumipes) on old wall where host species nests, Hertfordshire, England, UK, April

Andy Sands / Nomad bee (Nomada flava) a 'cuckoo bee' who lays its eggs in the nests of various Andrena bees, Herfordshire, England, UK, May

Andy Sands / Cuckoo Bee (Epeolus cruciger) about to enter the burrow of a mining bee where its larvae feed as a cleptoparasite. West Sussex, England, UK, August.

Stephen Dalton / Vestal cuckoo bumblebee (Bombus vestalis) in flight towards Cranesbill geranium, UK

Stephen Dalton / Vestal cuckoo bumblebee (Bombus vestalis) flying to Cranesbill geranium flower, UK

Andy Sands / Cuckoo Bee (Epeolus cruciger) feeding on Heather flowers, Hampshire, England, July

Andy Sands / Cuckoo Bee (Epeolus cruciger) feeding on Heather flowers. Hampshire, UK, July.

Nick Upton / Nomad / Cuckoo Bee (Nomada fulvicornis) sun basking on a leaf, Wiltshire garden, UK, April.

Nick Upton / Cuckoo bee (Melecta albifrons) a parasite of Hairy-Footed Flower Bees (Anthophora plumipes) and other masonry bees, searching an old wall for host nests. Brandenburg, Germany, April.

Nick Upton / Cuckoo Bee (Melecta albifrons) a parasite of Hairy-footed flower bees (Anthophora plumipes) emerging from host nest in an old wall. Brandenburg, Germany, April.

Nick Upton / Female Hairy-footed flower bee (Anthophora plumipes) prevented from entering her burrow in an old wall by a brood parasitic Cuckoo Bee (Melecta albifrons) Brandenburg, Germany, April.

Nick Upton / Sharp-tailed bee / Cuckoo bee (Coelyoxis sp. probably C. inermis) a kleptoparasite of Leaf-cutter bees, feeding on Mock orange flower (Philadelphus coronarius "Aureus"). Wiltshire garden, UK, June.

Nick Upton / Cuckoo / Yellow nomad bee (Nomada flava) feeding on Mock orange flower (Philadelphus coronarius 'Aureus') garden, Wiltshire, UK, June