While working in the outhouse yesterday, a tortoiseshell butterfly fluttered up and down one of the windows, frantically trying to free one of its wings from a strand of cobweb to which it was attached. It’s fight for survival took me back to the first year we came here, when the farmer, whose field adjoins our garden, grew a border of rape around the barley in his field, as supplementary food for his sheep.
In late July and August, hundreds of cabbage white caterpillars, crawled from the leaves of the rape, over the stone-dyke wall, across the bare expanse of our garden and up onto the walls of our house where they set about making their chrysalises. This gave me an idea.
After our boys had gathered little twigs from the garden, we placed them inside a large plastic aquarium. Then we set about collecting a fair number of caterpillars before they reached the walls of the house, and put them inside the tank, whereupon they began attaching themselves to the twigs. When they were all safely inside their cases, we covered the tank with clingfilm, making lots of breathing holes on the top.
We put the aquarium in a dark cupboard till the following April, when we transferred it to the patio window, from where, over the ensuing weeks, we watched fascinated, as, one by one, the caterpillars emerged from their chrysalises, dried their wings in the sun and flew away to freedom. Each year, I leave patches of nettles growing amongst our herbaceous borders for the cabbage whites to lay their eggs on, but they always prefer my nasturtiums.