Butterfly Survey 1976-2025
Nymphalidae
Small Tortoiseshell Aglais urticae
Wingspan - 48 mm
This butterfly was the commonest in the UK when the study started, but was often misidentified by the lay public as a 'red admiral', which was, like the term sparrow, a sort of generic title for all orange or red butterflies. This smaller, brighter butterfly is a resident here in the UK and overwinters indoors as an imago emerging in spring - sometimes as early as January (2022) FB Butterflies of Kent.
This mating pair are overwintered butterflies showing signs of fading through long months on the wing and in hibernation. The summer brood is on the wing from early summer and can be found anywhere that nettles grow. In sharp decline, 2005-2015, now making a comeback, with the pattern of distribution shared with other species, therefore diminished in the area under study. However, the disastrous spring of 2024* meant a decline in the fortunes of the butterfly that had already been showing disease and parasitic decline
There is in the old records, migratory movements of the small tortoiseshell from the near continent, probably Holland, which if now curtailed by recent agricultural practices, could account for its decline in Kent. The decline has also been linked to disease, but coincides with the adoption of energy saving home improvements - a diruptive and preclusive measure to the butterfly's winter hibernation pattern. Aestivation is a feature of the butterfly in very hot summers.
Habit: formerly, widely distributed - could be seen in rough uncultivated pastures, in fields and gardens and along any margins where nettles grow. It is very likely that this generation of people, who have grown up with affluence, by making flowery gardens, destroying nettles and paving drives, have inadvertantly contributed to the decline in suburban areas of this commonest British butterfly.
Chalmers Hunt writes in 1960 of a more realistic view of this butterfly than traditionally conceived, that in certain suburban areas between the 1910's and 1940's it was subject to fluctuation in the Sidcup area, for instance. In the same passage, he then refers to mass migration arrivals along the North Kent coast - hundreds of small tortoiseshells.
Double brooded: In Spring and Summer - the larvae are typically spiny - chrysalis is white/grey and can often be seen suspended from old style window frames and old doorways - possibly where access is easy for the imago.
Larval food plant: stinging nettle - eggs laid in groups.
WH-White Hill, SH-Shoreham, BC-Bromley Common, Ha-Hayes, BN-Bromley North, BR-Bromley Wider,Ey-Eynsford, Orp-Orpington (Ruxley), Lull-Lullingstone, HE-High Elms, BIC-Bickley, Bec- Beckenham
Thanks to Howard Walmsley
© Rodney Compton