Tuesday, 26 June 2012
The pretty hungry caterpillar
We have been watching a group of very colourful caterpillars in the garden over the last few days. Many of you will recognise these caterpillars from the image, but perhaps have wondered what species it is and whether the adult is equally visually stunning. A strong clue to the caterpillars identity is its favourite food plant, Mullein, and hence its name the Mullein Moth (Shargacucullia verbasci). Our particular caterpillars featured are feeding on Great Mullein (Verbascum Thapsus) with its distinctive velvety elephant ear-like leaves - or what’s left of them. This moth will also feed on other Verbascum species, but also Figwort (which I have more frequently observed) and Buddleia.
The caterpillars seem unconcerned with their high visibility ‘jackets’, almost advertising their bright yellow and black markings – this is presumably to warn any predators not to eat them because they taste bad. This stunning colouration is in stark contrast to the adult moth form which at rest appears to mimic a dead plant stalk.
Many gardeners are all too acutely aware of how prone their Verbascums are to attack by the caterpillar of the Mullein Moth, which can consume much of a plant's entire foliage in a day. I counted only about three caterpillars on our Great Mullein and today we are left with little more than a stump. However this is where their colouration works against them as they are easy pickings for green-fingered predators!