Nick Upton / Two Dark green fritillary butterflies (Argynnis aglaja) and a Narrow-bordered five-spot burnet moth (Zygaena lonicerae) nectaring on a Greater knapweed flower (Centaurea scabiosa) in a chalk grassland...

Nick Upton / Six-spot burnet moth (Zygaena filipendulae), Marbled white butterflies (Melanargia galathea) and a Dark green fritillary (Argynnis aglaja) nectaring on a clump of Greater knapweed flowers (Centaurea s...

Nick Upton / Close-up of a Dark green fritillary (Argynnis aglaja) nectaring on a Greater knapweed (Centaurea scabiosa) flower and flying off, Wiltshire, England, UK, July.

Lorraine Bennery / Knapweed fritillary butterflies (Melitaea phoebe) on Green winged orchid (Anacamptis morio), Grands Causses Regional Natural Park, France, May.

Ross Hoddinott / Marsh fritillary {Euphydryas aurinia} butterfly resting on Meadow thistle flower {Cirsium helenoides} Dunsdon, Devon, UK. June

Nick Upton / Dark green fritillary butterfly (Argynnis aglaja) nectaring on a Greater knapweed flower (Centaurea scabiosa) in a chalk grassland meadow, Wiltshire, UK, June.

Nick Upton / Two Dark green fritillary butterflies (Argynnis aglaja), Marbled white butterflies (Melanargia galathea) and a Narrow-bordered five-spot burnet moth (Zygaena lonicerae) nectaring on a Greater knapweed...

Nick Upton / Dark green fritillary (Argynnis aglaja) nectaring on a Greater knapweed flower (Centaurea scabiosa) in a chalk grassland meadow, joined by a Meadow brown butterfly (Maniola jurtina), Wiltshire, Englan...

Nick Upton / Marbled white butterflies (Melanargia galathea) and a Dark green fritillary (Argynnis aglaja) nectaring on a clump of Greater knapweed flowers (Centaurea scabiosa) in a chalk grassland meadow, Wiltshi...

Ross Hoddinott / Silver-washed fritillaries (Argynnis paphia) feeding on knapweed, Meeth Quarry, Devon, UK. July.

Konrad Wothe / Slow motion clip of Ringlet (Aphantopus hyperantus) nectaring on a Knapweed (Centaurea) flower with a Fritillary (Melitaea), distrubed by another, Bavaria, Germany, July.

Konrad Wothe / Slow motion clip of male False heath fritillary butterflies (Melitaea diamina) on a Knapweed (Centaurea) flower, disturbing a Ringlet (Aphantopus hyperantus), Bavaria, Germany, July.