Identification

Butterflies and moths are among the most recognisable insects. They are distinguished from most other insects by wings that are covered in microscopic scales. It is the scales that give these insects their distinctive colour patterns.

The mouthparts of almost all adult butterflies and moths are used to suck nectar from flowers and can be very long; when not in use they are coiled up like a watch spring on the underside of the head. Butterflies and moths undergo complete metamorphosis, with a caterpillar stage which feeds on plant material. Many caterpillars feed exposed on foliage, whilst others feed within folded leaves, are leafminers, bore into wood or fruits, or feed on plant roots.

Butterflies fly by day whereas moths are typically on the wind at night. However, several colourful moth species fly by day, including the burnet moths (Family Zygaenidae) and the cinnabar moth (Tyria jacobaeae).

British butterflies belong to a number of different families, and can be distinguished from moths by their clubbed antennae. Moth families are divided into the Macro-lepidoptera (Larger moths) and the Micro-lepidoptera (Smaller moths). This is an artificial separation based on general size; the larger moths can usually be identified by using pictures, whilst the smaller moths often require the use of a microscope and examination of the genitalia.

Size

The wingspan of moths and butterflies in Britain ranges from under 1 cm (for example the horse chestnut leaf miner, Cameraria ohridella) to over 10 cm (for example the privet hawk moth, Sphinx ligustri).

Distribution

Everywhere in the UK.

Status

Over 150,000 species of Lepidoptera have been described worldwide. More than 4,000 species are resident in the UK, 59 of which are butterflies. Additional species migrate to the UK each year but do not usually breed here, including the humming bird hawk moth (Macroglossum stellatarum). All but 16 species of butterfly have restricted distributions in the UK, and many species of moth are thought to be in decline. Biodiversity action plans have been devised for 11 butterfly and 53 moth species.

Where to them in the garden

Adult butterflies visit flowers by day, and after dark moths also visit flowers to gain a nectar rich meal. The caterpillars of several species can feed on garden plants, including of the 8cm long elephant hawk moth (Deilephila elpenor) on Fuchsia and the large white butterfly (Pieris brassicae) on cabbages.

Role in the garden

Butterflies and moths provide extra colour and interest to the garden. The butterfly bush (Buddleja davidii) attracts many species of butterflies including the Peacock (Inachis io) and Red Admiral (Vanessa atalanta), but there are many other plants that are valuable to butterflies. Butterflies and moths carry out some service in pollinating plants, but it is perhaps what the garden can provide for butterflies and moths that is more important; a rich nectar resource, which is vital for adult butterfly and moth survival. Some caterpillars may be seen as garden pests; caterpillars of the small white butterfly (Pieris rapae) and cabbage moth (Mamestra brassicae) damage brassica crops. Other caterpillars, such as the impressive puss moth (Cerura vinula) can occur in gardens but do not cause significant damage to plants.