How to identify a butterfly species

Where to start

You can identify a butterfly to species — and in most cases you do not need to catch it, pin it, or use a microscope. A good photograph and a systematic approach are enough.

Identification means narrowing possible species step by step. Each new trait rules out some options until one or a few candidates remain to compare in detail.

Step 1: record the context

Before focusing on the butterfly, note the circumstances of the encounter — they sometimes rule out whole groups:

Where: meadow, woodland edge, forest, bog, garden, mountain slope, coast. Many species are tied to habitat. The large blue occurs only where thyme grows. Ringlets — peat bogs and wet meadows. Apollo — only high mountain meadows with stonecrop.

When: month and approximate time of day. First spring species (small tortoiseshell, brimstone, mourning cloak) appear in March–April; some geometrids fly in November. Butterflies active in sunny hours — so one seen on a cloudy day is more likely a crepuscular or nocturnal species.

Region: central Russia, Russian Far East, Caucasus, Urals — faunas differ greatly. Maack's swallowtail occurs only in Primorye; Apollo is a rarity near Moscow but common on the Urals.

Step 2: estimate size

Before details, ask mentally: how large is the butterfly?

Size immediately excludes families. If wingspan is under 25 mm, it is certainly not swallowtail or Apollo.

Step 3: determine the general colour type

Look at the upper side of the wings (if the butterfly has them open):

• White or yellowish → likely whites and yellows (large white, green-veined white, wood white) or brimstone.
• Orange with black pattern → brush-footed butterflies: small tortoiseshell, male brimstone, fritillaries, checkerspots.
• Blue → blues (males), rarely some nymphalids.
• Brown, cryptic, with eyespots → fritillaries, satyrs.
• Black with white spots → mourning cloak, Apollo, some nymphalids and whites.
• Bold mixed pattern → nymphalids, swallowtails.

Detailed sorting by shade — in the wing colour identification guide.

Step 4: look at wing shape

Silhouette is often recognised before colour — especially in flight.

• Tails on hindwings → swallowtails (large, broad tails) or blues (small, thread-like tails).
• Angular, “ragged” edges → brimstone, comma.
• Very narrow, arrow-shaped wings → hawkmoth (nocturnal) or skipper.
• Broad rounded wings → most nymphalids and whites.
• Wings with eyespot patterns → fritillaries, giant silkmoths.

More detail — in the wing shape identification guide.

Step 5: check the antennae

Antenna shape is key for separating day-fliers from nocturnal species:

• Club-shaped (thickened at the tip) → day-flying butterfly (superfamily Papilionoidea).
• Thread-like or feathery → nocturnal butterfly or moth.
• Hooked at the tip → skipper (also day-flying, but a separate group).

If antennae are club-shaped, you already know you are dealing with one of ~350 Russian day-flying species — not 1,800+ nocturnal ones.

Step 6: look at the underside

Many species look alike above but differ easily below. For this the butterfly must fold its wings — day-fliers do this automatically at rest.

• Comma: underside mimics bark with a small white “C” on the hindwings.
• Blues: underside often patterned with dots and rings — each species has its own design.
• Brimstone: underside green, leaf-like.
• Red admiral: underside of hindwings a mosaic of grey, brown, and rusty tones.
• Green hairstreaks (Callophrys rubi and others): green below — unique among small butterflies.

Step 7: rule out look-alikes

Many species have near duplicates. Common mistakes:

Large white vs. green-veined white: both white. Green-veined white has one large black spot on the forewing above (large white has two); the underside of the hindwing is uniformly yellow in green-veined white, with dark veins in large white.

Small tortoiseshell vs. large tortoiseshell (Aglais urticae vs. Nymphalis polychloros): in the large tortoiseshell the forewings have four dark spots, wings are larger, and the blue border is less prominent.

Male blues: most are blue above. They are separated by size, underside details, and nearby host plants.

Fritillaries: several similar species. Identification relies on the pattern of the underside of the hindwing — the silvery “pearly” spots are unique to each species.

How to take a good identification photo

If you want to identify later from a photograph:

1. Upper side with wings open — for the general pattern.
2. Underside with wings closed — for many species this is the key shot.
3. Head close-up — antenna shape visible.
4. Wide shot with a plant or landmark — helps judge size.

A good RAW or high-resolution photo allows cropping details. Shoot from the side or front — profile and antennae show well.

Online tools and apps

Several services help with photo identification:

iNaturalist — international platform: upload a photo, an algorithm suggests options, and the community of entomologists confirms or refines. Free, worldwide coverage, a large database of observations from Russia.

LepiDiv and other European databases — good sources for European Russia.

Identification keys of the Russian Entomological Society — for advanced identification, especially difficult groups (blues, fritillaries, geometrids).

Apps such as Seek (from iNaturalist) recognise species in the camera view — they work reasonably well for large, bright species; for small or rare ones, specialist verification is needed.

When identification is difficult

Some species need a specialist or collection material:

• Small nocturnal species (ermine moths, clothes moths, geometrids): hundreds of similar species; differences in venation or genitalia.
• Female blues: most are brownish; separation is subtle.
• Prominents and some owlet moths: variation within a species often exceeds differences between species.

If you cannot identify the species — upload to iNaturalist marked “needs ID”. The community actively helps.

Algorithm in one table

What to read next

Use atlas sections in sequence: by wing colour, by wing shape, by size. If you already know the family, go straight to its page: brush-footed butterflies, whites and yellows, blues, swallowtails. Common identification mistakes are covered on common mistakes.