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Brimstone

 

 

A few hours of sunny and wind-sheltered weather brought butterflies out flying. This summer cannot be called a “butterfly summer”, in places there were complaints about outright lack of butterflies. We were lucky yesterday, in North-West Estonia the small tortoiseshell as well as the brimstone and the peacock were out flying – always the ones that hibernate as imagos. The great majority of our large butterflies winter as eggs or pupae, a minority as caterpillars or imagos.

 

The brimstones winter in the leaf debris or moss on the forest floor. With luck  brimstones are truly long-lived, up to 13 months. How can a small organism endure for so long? Summer plants are not skimpy with nectar; this allows the brimstones to feed well  and after that they can confidently allow themselves a holiday of some weeks, a diapause. In preparing for winter the brimstones store glycerine and sorbitol  as well as proteins in their bodies; this protects them against cold of up to some twenty degrees, and the spring sun will warm the butterflies nicely awake.

 

 Small tortoiseshell

 

The small tortoiseshell, the ”herald of a many-hued summer”, should in theory appear before the brimstones in early spring since it winters at forest verges and not on the forest floor. Years differ, but often the last unmelted snowdrifts are to be found on the forest outskirts. So they delight us at much the same time in spring.

 

Peacock

 

The peacock slipped in through the country house door almost at once as I took  a look on the yard and a few minutes later it had skilfully hidden itself. They winter readily in human habitations and temporary heating in winter signals to them that it is time to wake up. Years ago a Looduskalender reader asked what to do with a peacock that has waken up in the country house in mid-winter. Of course such a waking up is an energy-consuming act and if it were to happen often then the butterfly’s organism would not endure until spring. The recommendation is simple – put a wad of cotton wool with sugar solution or similar on the windowsill. When the butterfly finds the  dish its belly can be filled and when the temperature drops it can peacefully wait for the real spring.