Posted: Wednesday 26 February 2014
by Richard Jones
Just over a week ago I spotted this critter in our downstairs loo. It’s the ‘light brown apple moth’, a male.
Over Christmas and New Year the cistern in the downstairs toilet was covered in a light dusting of tiny frass particles. Part or our minimalist decorating scheme had been a few sprigs of variegated euonymus and ivy foliage in an elegant cut-glass vase. I looked several times, but it took me a fortnight to eventually find the small green caterpillar that had been releasing the droppings; it was hidden between two leaves spun together.
The trouble with most moth caterpillars is that they are just long, thin, tubular eating machines, and there is precious little to tell one species from another. I let the matter rest. Eventually the frass stopped falling. I should have twigged then, really.
Just over a week ago I spotted this critter. It’s not a brilliant picture, but it is distinctly Epiphyas postvittana, the ‘light brown apple moth’, a male.
As a not-very-real gardener, I can be quite relaxed about this moth, but some people might regard it as a pest. It’s a native of Australia, where it feeds on a wide range of native and garden plants including, as its name suggests, apple. It is more or less kept in check there my natural predators, but like so many foreign invaders, when it got to North America everyone panicked. In the USA and Canada it is considered a noxious pest, even though crop losses have been minimal, if at all.
The worry is that it is highly polyphagous, which means it will eat almost anything. As a non-native it has the potential to feed across a huge range of habitat and climate zones, on a vast range of food plants. It’s established in California, and they’re trying to contain or control it by using disruptive pheromone lures. Time will tell, I suppose.
We’ve had this moth in the British Isles for nearly 80 years, and although it is very common and pretty widespread, it has not brought devastation and destruction. As a wet temperate oceanic island system we often get off lightly when it comes to invasive species. We’ve just cut down the vigorously growing euonymus bush to make some new beds for herbs and fruit. I’m sure the moth will find something else to nibble out there.