Hertfordshire & Middlesex Branch
Saving butterflies, moths and our environment
Distribution and Status
The Dark Green Fritillary is generally found only on chalk hillsides in our area. In the 1980s it was seen in many suitable areas on the western, northern and eastern edges of Hertfordshire but by the end of the 1990s the butterfly had disappeared almost completely in these areas too apart from a possible colony in the Tring area. However, since the beginning of this century there has been a partial recovery in Hertfordshire with the best spots at Hexton Chalk Pit, Aldbury Nowers and Therfield Heath. A colony was recently discovered in a field off Walkern Road near Benington. It is possible it is returning to Middlesex after several decades
Habitat Requirements
Chiefly on calcareous grassland
Larval Foodplants
Common Dog Violet Viola riviniana, Hairy Violet V. hirta on the chalk
Adult Food Sources
Red Valerian Centranthus ruber, Buddleia Buddleja davidii, Spear Thistle Cirsium vulgare
Behaviour/Observation notes
This species is a low-flying insect with males spending much time patrolling over the vegetation in search for females which are more inconspicuous. However, in early morning and evening, it is often found feeding on flowers like thistles and knapweeds to provide opportunities for good photographs although to photograph the undersides you may need to wait until the middle of the day when the temperature rises
Life History
The Dark Green Fritillary is on the wing from June to the end of July with a peak often in the first week of July. The eggs are laid on or near violets. After the larva emerges it eats the eggshell and immediately enters hibernation. On emergence in the spring the larvae eat the leaves. When fully grown it creates a tent, using the leaves and other vegetation, in which a pupa will be formed
Further information
Photo gallery
Branch Annual Report (2023)
UK distribution map
Full list of larval hostplants (Nymphalidae)
Stevenage butterflies - additional notes
Account for 2022