Heath Fritillary

Melitaea (Mellicta) athalia/nevadensis


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All pictures, I believe, are of Melitaea nevadensis - see notes below

Melitaea nevadensis

Male, Switzerland, June 2016

Melitaea nevadensis

Male, North Italy, June 2017

Melitaea nevadensis

Male, Switzerland, June 2018

Melitaea nevadensis

Male, Switzerland, July 2019

Melitaea nevadensis

Male, Switherland, June 2017

Melitaea nevadensis

Male, Switzerland, June 2017

Melitaea nevadensis

Switzerland, JUne 2018

Heath fritillary - Melitaea athalia

Male, Switzerland, August 2013

Heath fritillary - Melitaea athalia

Male, Switzerland, June 2013

Heath fritillary - Melitaea athalia

Female, Switzerland, July 2013

Switzerland, June 2005

Switzerland, June 2005

Switzerland, June 2005

Switzerland, June 2005

Melitaea athalia and nevadensis distribution

Most authors agree there are two species - Melitaea nevadensis and Melitaea athalia - under the umbrella of what used to be known as Melitaea athalia, the heath fritillary. Nevadensis corresponds for the most part to the former subspecies celadussa (though there was always doubt about the correct application of that name). There seems to be a broad area of intermediate specimens or hybrids where the two distributions overlap - including the regions all the above pictures were taken in - and I'm not sure there is a definitive way of telling the two species apart anyway, so it makes sense for me to treat them together here.

Heath fritillaries are common in most of Europe from sea level to above the tree line, though extremely rare in the UK, where they are restricted to a few sites in the south of England. They may be seen flying with a determined, often gliding flight over flowery meadows, along forest rides and on high alpine hillsides, often stopping to nectar.

There is much altitudinal and geographical variation, from large, open and bright butterflies in the south of the range and at low altitude, to much darker, often smaller butterflies in the north (ssp. norvegica in Scandinavia) and at altitude. In all forms, the butterfly is characterised by the rather irregular pattern of the grid-like markings on the upperside and heavy submarginal branding on the underside forewing in ss.2-3 (when visible, this separates heath fritillaries from Provenšal or meadow fritillaries). The discal markings in s.1 of the upperside forewing are very variable but never neatly oblique, as in meadow fritillary, not formed into a well-defined dumbell as is common in Provenšal fritillary. The most similar species are the Provenšal, Nickerl's and Assmann's fritillaries - all of which are generally rarer and more local. Normally, the butterfly-watcher will be seeking to confirm one of these, rather than the default heath fritillary, and so will be looking for their distinctive characters.

The caterpillars feed on a variety of plants, including plantains, speedwells, cow-wheats, toadflaxes and others. They live gregariously in webs before hibernation, then disperse afterwards. There is usually just one, protracted generation, from May through to August, though partial second broods occur in some years, in good conditions.