Small and Pearl Bordered Fritillaries are best distinguished by the patterns on the undersides of the rear wings.
Flight times are another indicator, as the Pearl-bordered Fritillary can appear on the wing in late April. However, there can be an overlap of the two species in June, so wing markings are the most reliable identifiers. To examine wing markings, you need to get up close, so binoculars or a net are recommended.
The following illustrations compare the rear wing patterns of each species. These are reproduced from the leaflet "Learn about the Pearl-bordered Fritillary" published by Butterfly Conservation Scotland.
Wingspan 38 - 46mm (male), 43 -47 mm (female).
Ova are laid singly on dead bracken or leaf litter near the foodplant, dog-violet or occasionally marsh violet. Larvae hibernate, usually in September. They emerge again on sunny days in March.Pupation lasts 2-3 weeks.
Late April to June.
Remains quite widespread in the north of Scotland, inhabiting many of the inland glens up to Invershin in the east.
Butterfly Conservation Scotland (2005). Learn about the Pearl-bordered Fritillary (leaflet).