Early hibernation?

[Simon-in-Kent]

Yesterday I came upon a Small Tortoiseshell that was flying around the inner rooms of a local antiques centre in the mid-afternoon. It found a crevice behind a wooden picture rail, flew in...and that was that. Today a Peacock was exploring the nooks and crannies of our lounge - blazing hot sun outside, of course. I have come across sleeping Small Tortoiseshells during the day at this time of year before - one was in a garage, another in a country house's orangery. Recently I chanced upon a website - http://www.phegea.org/dagvlinders/BinkM ... rticae.htm - that claimed that some first-brood Small Tortoiseshells go into early diapause as a kind of fail-safe should the summer weather become unfavourable: "flexible diapause in the adult stage, one clutch produces a percentage of individuals that will enter diapause despite warm weather and long daylight." I'd be interested in anyone's views on all this!

[Mark Colvin]

Hi Simon.

I'm not surprised by your find as I found some 15 individuals entering hibernation on 31st July 2015. They stayed in this state for eight months and only occasionally showed signs of any movement. The theory of spreading the risk by having a 'flexible diapause in the adult stage' is one I've not heard of but would seem to make perfect sense. Thanks for the link.

http://markcolvin.blogspot.com/2016/08/the-sleeper.html

Good hunting.

Kind regards. Mark

[David M]

Certainly, Peacocks and Brimstones will disappear in late summer to find places to spend the winter months in, but Small Tortoiseshells will regularly stick around until the first frosts in late October/early November.

[Simon-in-Kent]

Thank you Mark - that's most interesting. That would make the ST a bit like the Comma, with some first generation butterflies saving their sperm/eggs for the following year, and living for 10+ months as adults. But of course you can't tell which version of the ST is which, since they don't have light and dark forms like the Comma. I wonder if there's nevertheless some physiological difference....

[MrSp0ck]

Peacock often are in hibernation quarters in the first week of August, we find them in the pill boxes along the ridge of the north downs near Dorking most years, often with Herald Moths. I have seen Peacocks coming out of fox holes and badger sets in the Spring, so expect they also use them for the winter on sites.