RSPB Gardening for Wildlife

As a child, I could identify every species of butterfly that visited my garden. Moths, on the other hand, I blatantly ignored. As far as I was concerned, they were drab, boring and unidentifiable.

As its name would suggest, the Garden Tiger was once a common sight in gardens, but numbers have declined dramatically. Climatic changes may be responsible for the falls as the Garden Tiger caterpillars’ food plants – garden plants – remain common.

So it was an eye-opener when, two decades later, I started moth trapping in my tiny suburban garden. The technique is to lure them at night with special lights and then release them unharmed the next day. In one summer’s night, a tiny garden can easily catch 200 moths of 30 species. And I started finding things like this…

It’s an Elephant Hawkmoth Deilephila elpenor; I had no idea that shocking-pink, fluffy monsters were out there in gardens.

And I love this one, the Buff-tip Phalera bucephala, designed to look like a broken twig. What amazed me most was that these are common garden species, but without trapping them you just wouldn’t know that they are there.

But not all moths are nocturnal. Every year the RSPB get dozens of phone calls from people saying they have a hummingbird in their garden, hovering at flowers and sucking nectar through its beak.

It’s this, the Hummingbird Hawkmoth Macroglossum stellatarum, with its amazing tongue, and there are other funky daytime species too.

If I still haven’t won you round to moths’ charms, then there’s another reason to love them – their importance in the food chain. For many bird species in particular, moths are vital. Tits, Goldcrests and many others eat not only the adult moths but their eggs, caterpillars and pupae. Bats, of course, eat moths, too, and long-eared bats even pluck caterpillars off leaves.

It all adds up to the conclusion that you’ve just got to garden for moths, and the great thing is that there is plenty you can do for them.

The Mint Moth Pyrausta aurata is a familiar visitor to the herb garden – the adults nectar on mint and Marjoram flower, the caterpillars eat the leaves.

There is a mind-boggling myriad of moths. More than 2,400 species have been recorded in the British Isles, about a third of which are the so-called ‘macro moths’, which are generally at least the size of a 5p piece and often much bigger. The ‘micros’ in comparison are usually very small indeed, and very difficult to identify.

Picking out the home needs for each and every moth would, of course, be a long read, but we can at least make some good general observations.

Distribution: There are moths to be found pretty much everywhere. The number of species thins the further north or the higher you go, but these places have their own specialities.

Habitats: Moths occupy almost every habitat you can think of. They are perhaps most numerous in woodland, but there are moths on the coast, in wetlands, in mountains, and there are plenty that find a good home in gardens, even in urban areas.

Habits: Most moth species fly by night. Without the heat of the sun to warm them up, many of them have to vibrate their wings vigorously before they can get airborne. Damp cloudy nights are often best. Why many species fly towards lights is still not fully understood, but it may be that the construction of their eyes makes them think they are flying away from them. Many wander widely, ending up in unsuitable habitats, and some are even long-distance migrants.

Roost: Every moth must hide away before daylight comes in a place where birds won’t find them, so plenty of dense vegetation is vital.

Food for the caterpillars: Different moth caterpillars eat different things, from plant leaves to flowers, seedpods, dead leaves, algae, roots and living wood. If we take all the common macro moths in the British Isles and those which are more local, but which turn up in gardens, just under 400 species in all, we find that:

About 20 per cent of species aren’t fussy, eating all sorts of herbaceous plants

About 15 per cent eat the leaves of all sorts of broadleaved trees, without restricting themselves to one species

All the rest are specialists, eating just one particular family or species of plant. If you don’t have that plant in your garden, that’s it, the moth can’t breed there. Some of the key plants are trees – especially willows, birches, poplars, hawthorns, oaks and Blackthorn. Now you can see why so many insect-eating birds spend so much of their time in trees. In terms of herbaceous plants, bedstraws are popular. Beyond that, there are more than 100 different plant species that each have their own specialist moths. And that doesn’t even begin to take account of the micro moths.

Food for the adults: Some adult moths need to drink sweet liquids, but many don’t – some don’t even have functioning mouthparts. For those that do, top tipples are the fermenting juice of overripe blackberries, the nectar of Ivy, sallow catkins, ragworts, Red Valerian, honeysuckles and campions, and aphid honeydew.

Breeding: Much of the adult male moth’s life is spent searching for a mate in the dark; the females sit waiting to be found, often pumping out scent. Once mated, the females have to find the right plants in the dark on which to lay their eggs.

The Cinnabar caterpillar is a familiar sight on ragwort in summer – the yellow and black stripes signal that it is very unpleasant to eat, and so there is no need for it to hide.

You can tell the finger-sized caterpillars of hawkmoths by the ‘thorn’ on their rear end. This is the Privet Hawkmoth, which feeds on privets, ash and various other shrubs.

OK, maybe that’s a bit ambitious. But at least here is a starter guide to some of the main groups of macro moths.

Six-spot Burnet

Boldly patterned red and dark metal-green, and with black hockey-stick antennae, the three common species fly by day in midsummer. They live in colonies in flower-rich meadows where their caterpillars eat bird’s-foot trefoils and clovers, and the adults nectar at knapweeds, scabiouses and Viper’s Bugloss.

Mostly nocturnal, this is a large family of slender-bodied moths that tend to hold their wings out flat (apart from the group called the thorns, which hold them in a ‘V’ or even ‘up like a sail’). This family includes groups of moths such as the carpets, pugs and waves, of which many different species visit even small gardens. It also includes the master of camouflage, Willow Beauty Peribatodes secundaria (above), and the common and distinctive Magpie Moth Abraxas grossulariata. These moths fly weakly, expending little energy, so few need to nectar at flowers and some are able to emerge in midwinter. Their ‘looper’ caterpillars have a gap between the front three pairs of true legs and the two pairs of hind legs (prolegs) that allows them to crawl quickly by looping their rear end up behind their front end.

Willow Beauty

Magpie Moth

Helping Geometrids is all about helping their caterpillars, a great many of which feed on woody plants, especially native trees and shrubs.

Guaranteed to wow the kids, these are the giants of our insect world, with the Privet Hawkmoth Sphinx ligustri having a 12cm wingspan. As its name suggests, its caterpillar feeds on Garden and Wild Privet. Other common and no less dramatic species include (with caterpillar foodplants in brackets): Poplar Hawkmoth Laothoe populi (poplars); Lime Hawkmoth Mimas tiliae (limes, elms); Pine Hawkmoth Hyloicus pinastri (Scots Pine); Small Elephant Hawkmoth Deilephila porcellus (bedstraws); as well as the two we’ve already seen (both here), Elephant Hawkmoth (bedstraws, willowherbs and garden fuchsias) and Hummingbird Hawkmoth (Lady’s and Hedge Bedstraws). The caterpillars of all of them are impressive.

Adult hawkmoths (bar Privet and Lime) feed at tubular flowers such as honeysuckles and Tobacco Plant. Hummingbird Hawkmoths feed at Red Valerian, lavenders, Verbena bonariensis and fuchsias. They set up feeding rounds, returning to the same plant every hour or so over several days.

Lime Hawkmoth

Privet Hawkmoth

These are rather chunky moths that sit with their wings held like a ridge-tent over their backs. The prominents are named after the little knobs along the rear edge of the moths’ forewings, which poke up when they are resting. They include the Swallow Prominent Phoesia tremula and the Pale Prominent Pterostoma palpina. The kittens are so called because of their supremely furry bodies, the largest of which is the Puss Moth Cerura vinula (oh, how I love moth names!)

These moths don’t feed as adults, so again nurturing them is all about satisfying the needs of their hungry caterpillars, which feed on tree leaves, each species having particular favourites, with birches, willows, oaks and Aspen particularly favoured.

Pale Prominent

Swallow Prominent

The Garden Tiger Arctia caja has wings that are more leopard-print than tiger-like. The day-flying Cinnabar Tyria jacobaeae, whose familiar yellow-and-black caterpillars feed on ragworts, is sometimes mistaken for the Garden Tiger. The Ruby Tiger looks quite different – its body is even brighter red than its wings. Its caterpillars are ‘polyphages’, meaning they eat all sorts of plants.

Garden Tiger

Ruby Tiger

This is a very large group of mainly night-flying moths, most of which have rather chunky bodies and hold their mottled brown and grey wings flat over their backs or like a ridge tent. These are fast and furious flyers, and need pit stops at flowers and honeydew to refuel. Two very common species are the Large Yellow Underwing Noctua pronuba, which you are likely to flush from long grass while mowing, and the Angle Shades Phlogophora meticulosa, which is very distinctive, having folded wing edges that look like origami.

Large Yellow Underwing

Angle Shades

Plant a tree. If you have a large garden, you can’t do any better than an oak. If you have a small garden, a hawthorn, fruit tree or willow would be great.

Plant a mixed native hedge. This is a way of growing trees without them becoming huge. You may not generate quite the same mass of leaves and branches, but you can pack in loads of different species and hence accommodate many moths.

Vegetation, vegetation, vegetation. The more you have, the more caterpillars your garden is likely to support.

Grow climbers up walls. Ivy is the best because it will provide nectar, too, but any dense climber offers great places for moths to hide by day.

Plant a wildflower meadow. Burnet moths will be the obvious sign of success, but you might be lucky to get a day-flying Burnet Companion or Mother Shipton, and think of all those species whose caterpillars feed on wild grasses.

Grow nectar plants for the adults. You’ll need to get out with a torch to see them being used, but that’s a mini-adventure in itself.

Grow an area of Rosebay Willowherb. It’s an attractive flower, some adult moths love it for its nectar, but if you then get Elephant Hawkmoth caterpillars, you are so going to thank me!

Rosebay Willowherb