Evergestis forticalis, otherwise known as The Garden Pebble Moth, belongs to the family Crambidae which includes the so called Grass Moths. This is a large Family with 140+ species recorded in Britain alone.
A medium sized moth with a 25-28mm wingspan(1). This is one that can be identified in the garden with a good photograph and reference material. It is double brooded and flies April-Oct (2).
It’s place in the Garden (Visitor/Lured)
The larva/caterpillars feed on the underside of leaves of various brassicas, cabbage, horse radish, radish, swedes (2). We are unsure if they feed on the wild brassica species we see in the Garden, such as Garlic Mustard, Hairy Bittercress and Hedge Mustard. Our garden is close to a large plot of alotments and obviously many people grow their own veg, so the chances are this species is simply visiting our Garden.
All stages of a moths development are subject to a wide range of predators. Including small mammals, birds and amphibians. Other invertebrates are also a major threat, including dragonflies, beetles, lacewing and wasps. As such whilst many view certain caterpillars as a pest, these small packets of protein help support a wide array of other beneficial and interesting species. Moths are of course interesting in their own right and are very welcome in the Garden.
How to encourage the species to your garden
Current distribution maps place this species across much of the UK, less frequent in Scotland. Introduction of food plants would therefore provide this species with opportunities to become resident in any garden, but with the food plants so abundant in the wider world, be that wild or cultivated, it seems less likely a female would focus in a small garden vegetable plot.
Therefore the best bet is to lure such moths to you by leaving a secure window open and a light on during the warmer months, or better still invest in a moth trap. Even if you don’t see this species, you may be visited by many other interesting species.
- UK Moths: Species Account Page. https://ukmoths.org.uk/species/Evergestis-forficalis/ – Accessed online 21st December 2022
- Sterling, P & Parsons, M (2012): Bloomsbury Wildlife Guides: Field Guide to the Micro moths of Great Britain and Ireland. Bloomsbury Publishing Ltd