Emily Hartley
Why stay up for moths?
Butterflies get the glory, but moths are the quiet majority of our Lepidoptera. Britain and Ireland hold something in the region of 2,500 moth species, against roughly 60 butterflies, and a decent suburban garden in southern England can notch up 250 of them over a year without trying very hard. They are pollinators, they are food for bats and birds, and they turn up in astonishing variety — from the pink-and-olive confection that is an elephant hawkmoth to micros so small you need a hand lens to admire them properly. The good news is that you do not need a licence, a field station or any particular expertise. You need a warm evening, a bit of patience, and somewhere to put a light.
A light trap, pared back to basics
Commercial traps are lovely, but most of us start with something improvised. A white sheet hung over a washing line, a fence panel or the side of a shed, with a bright torch or a small actinic bulb at the top, will draw moths in. They settle on the fabric rather than circling forever, and you can walk along with a torch of your own, examining them where they rest.
If you would rather keep them contained until morning, a simple box trap works well:
- A plastic storage box with a funnel taped into the lid, or a cardboard box with the flaps arranged as a funnel.
- An egg box or two inside — moths like something to hide in, and it keeps them calm and safe.
- A low-wattage bulb, ideally a purpose-made moth bulb, suspended just above the funnel.
- A sheet of corrugated card or a piece of old cardboard leaning against the outside, so moths that miss the funnel still have somewhere to settle.
Run it from dusk until about midnight, or leave it on all night if the weather is mild and still. Position it away from security lights and streetlamps, which will compete for attention and confuse the picture.
The sugar patch option
Some moths barely bother with light at all, but they cannot resist a sweet, slightly fermented smear. This is the old-fashioned method, and it works beautifully in a garden with mature trees and hedges.
Warm a jar of brown sugar with a splash of beer, cider or red wine — nothing expensive — and stir in a spoonful of black treacle and a mashed over-ripe banana if you have one. Paint the mixture onto a length of rope, a fence post, a tree trunk or a wooden post with a brush. Go out an hour or so after dark with a torch and look along your patches; the moths will be sitting there, wings folded, feeding. Sugar works especially well for the handsome noctuids — angle shades, burnished brass, the wonderfully named setaceous hebrew character — and it keeps drawing until well after midnight.
What might turn up
Expect the ordinary first: common quaker in March, heart and dart through summer, large yellow underwing in their dozens. Then the surprises start. Hawkmoths are the ones that stop people in their tracks — poplar, lime, eyed and elephant all visit gardens, and a freshly emerged privet hawkmoth is genuinely a garden event. Look out too for the buff-tip, which masquerades as a broken birch twig, and the puss moth, whose grey-and-pink outfit looks entirely invented.
The micros are a whole second hobby. A few minutes with a hand lens or a macro photograph will show you tiny feathery plumes, metallic speckles and species whose caterpillars mine inside a single leaf. You do not have to identify everything. Getting a species to family is a perfectly respectable evening's work.
Weather, timing and a gentle hand
Moths are fussy about conditions. The best nights are warm, cloudy, humid and still, with the temperature staying above about 8°C. A clear, cold, windy night is rarely worth the effort. May to September is the main season, but early spring brings the quakers and the Hebrew characters, and a mild November night can produce the remarkable November moth and its relatives. A little moonlight is fine; a full moon and a bright streetlamp are not.
Handle moths kindly. Pot them in a clear tub, chill them in the fridge for ten minutes if you need them still, and release them in a sheltered spot among vegetation rather than on an open lawn where a blackbird is waiting. Empty the trap at dawn, before the birds find it. And once a trap has done its work, switch it off — there is no need to hold moths captive until lunchtime.
Recording your finds
Keep a simple notebook or a spreadsheet: date, species, numbers, and a note on the weather. A garden list built over a few years becomes a genuinely interesting record, and county moth recorders are always glad of it — your ordinary back garden is exactly the sort of place that is under-recorded. Local moth groups run trapping evenings and identification sessions, and a good photographic field guide plus a friendly online forum will get you most of the way. Start with one warm night and a white sheet. You will be surprised what has been visiting all along.
