This picture is of Cabbage White caterpillars chomping away at nasturtiums (tropaeolum majus) in my garden.
Nasturtiums are, as is well known, fantastically easy to grow and I have wondered for a while why they also seem quite resistant to attacks by the snails and slugs that ravage everything else in my garden.
Nasturtiums are closely related to cabbages and this family of plants have developed what Tim calls “vicious” methods to deter insect attack (NB: Tim has not said this includes molluscs – I am hypothesising that on the basis of not much at all) through various poisons in the leaves. The Cabbage Whites have developed counter measures – a paper here describes this battle in some detail.
Having recently come to realise the deep links between genetics and computation I find this fascinating and the whole thing – the link between the seemingly mundane question of which plants grow well in a garden over-run with slugs while also offering some support back to native species and the continuum of maths, physics, chemistry and biology – seems to me like a celebration of the explanatory power of science and the immensity of the last fifty years of achievement by scientists in so many domains.