# Pea Blue (*Lampides boeticus*)

The Pea Blue, also known as the Long-tailed Blue, is a remarkably widespread and resilient butterfly belonging to the gossamer-winged butterfly family (Lycaenidae). A strong migrant, this delicate insect is one of the most widely distributed butterflies on Earth. It is a familiar sight in gardens and agricultural areas across southern Europe, Africa, Asia, and Australia. As its name suggests, the Pea Blue is inextricably linked to leguminous plants, often laying its eggs on peas, beans, and broom. Its striking coloration and fascinating survival strategies, such as a false head at the back of its wings that may confuse predators and caterpillars that share sugary drops with ants, make it a captivating subject for nature enthusiasts and lepidopterists alike.

- **Category:** [Insects](https://www.snappit.app/explore/categories/insect)
- **Rarity:** Common
- **Danger:** 1/5 · Very low
- **Snaps:** 1
- **Habitat:** Found in open woodlands, agricultural fields, meadows, and urban gardens, typically wherever leguminous host plants are abundant.

![Pea Blue](https://inaturalist-open-data.s3.amazonaws.com/photos/94496622/medium.jpg)

Photo: Mike Kerry, CC BY 4.0 · [iNaturalist](https://www.inaturalist.org/photos/94496622)

## Appearance

The Pea Blue is a small butterfly with a wingspan of 24 to 42 millimeters. Males boast a vibrant, iridescent violet-blue on their upper wings, while females are predominantly brown with blue dusting restricted to the wing bases. The defining feature for both sexes is the underside of their wings, which is grey-brown with many wavy brown lines edged with white. At the lower rear edge of each hindwing, they sport two prominent black eye-spots rimmed with bright orange, alongside a delicate, hair-like tail. This combination creates the illusion of a false head.

## Taxonomy

- **Kingdom:** Animalia
- **Phylum:** Arthropoda
- **Class:** Insecta
- **Order:** Lepidoptera
- **Family:** Lycaenidae
- **Genus:** Lampides

## Pea blue, up close

The pea blue (Lampides boeticus), also called the long-tailed blue, is a small butterfly in the gossamer-winged family Lycaenidae and one of the most widely distributed butterflies in the world, found from Britain to Japan and across Africa, southern Asia and Australia. Males are violet-blue above and females mostly brown, while both have a grey-brown underside with wavy lines, thin tails and two eyespots that form a “false head”. Its caterpillars feed in the flowers and pods of peas, beans and other legumes, and are often visited by ants.

Also called: Long-tailed blue, Long-tailed pea-blue, Pulse blue.

A fake head at the back, caterpillars that live inside pea pods, ant bodyguards and Channel crossings. Spin it, tap it, then test yourself.

### Special abilities

- **False Head** (5 false-head features scientists score; still debated): The back of the wings looks like a head, which may trick a predator into grabbing the wrong end. [2][3][1]
  - The tails stand in for antennae, the black eyespots for eyes, and wavy lines lead towards the fake face.
  - A study of 928 lycaenid butterflies found that these features tend to evolve together, building a more convincing fake head.
  - Losing a scrap of hindwing is far less dangerous than a bite to the real head, so scientists think the trick buys time to escape.
  - The evidence is still thin: a few small experiments support it, and researchers say more tests are needed.
- **Twitching Tails** (2 hindwings moved to wiggle the tails; still debated): Resting on a flower, the pea blue moves its hindwings so the thin tails twitch like antennae. [7][3]
  - UK butterfly experts describe the hindwings rotating while the butterfly rests, which makes the tails move.
  - Scientists think moving tails make the fake antennae more convincing to a hunter.
  - But in one experiment, hairstreak butterflies with their tails clipped were caught by mantises no more often than those with tails, so the tails’ job is still debated.
- **Nectar Sip** (8–9.5 days adult life in a lab study): Adults drink sugary nectar from flowers through a long tube that uncoils from under the head. [6][11][7]
  - The proboscis unrolls into the flower and coils back up after drinking.
  - Butterflies can drink a steady column of liquid, or a “bubble train” that draws up thin films of nectar.
  - In a lab study on field pea, males lived about 8 days and females about 9.5 days as adults.
  - In Britain, long-tailed blues are seen mostly around garden flowers.
- **One Egg per Bud** (0.5 mm egg width): A female lays her eggs one at a time on flower buds of peas, beans and their relatives, so each caterpillar hatches next to food. [7][1][12][11]
  - Each egg is a flattened, pale bluish-green to white disc, about 0.5 mm across.
  - Eggs hatch in 2–3 days in warm southern India and in about a week in an English summer.
  - In one lab study on field pea, each female laid about 14 eggs, on twigs, flowers and pods.
  - The new caterpillar eats a round hole in the top of its egg and soon bores into a bud.
- **Pea to Wings** (15–35 days egg to butterfly in warm countries): In warm places a pea blue can go from egg to butterfly in about 2 to 5 weeks, so there are many generations a year. [12][11][13][10][7]
  - In Indian studies: egg 2–3 days, caterpillar about 8–13 days, a short pre-pupa, then a chrysalis of 3–8 days.
  - The caterpillar has four stages (instars), with a moult between each.
  - In cooler England it is slower: about a week as an egg, 3–4 weeks as a caterpillar and about 10 days as a chrysalis.
  - On the continent it breeds continuously, one generation after another, but it cannot survive British winters.
  - Days in each stage on cowpea (India): Caterpillar 11.8 days; Chrysalis 5.2 days; Egg 3.2 days; Pre-pupa 1.4 days
- **Ant Bodyguards** (≈3/4 of lycaenid species live with ants): Pea blue caterpillars are often visited by ants, which drink sugary droplets from them and may protect them in return. [9][14][15][16]
  - About three-quarters of lycaenid butterflies associate with ants as caterpillars or pupae.
  - The pea blue does not depend on ants, but many kinds visit it, including carpenter ants, Iridomyrmex ants, the ghost ant and the invasive Argentine ant.
  - Lycaenid caterpillars reward ants with food from special glands and use chemical and sound signals to manage them.
  - The deal varies: in a related blue, one ant species helped female caterpillars grow into heavier adults, while others made no difference.
- **Channel Crosser** (60 adults that crossed to England in 2015): A strong migrant: most summers a few long-tailed blues fly north from the Mediterranean to Britain, and in some years many more cross the Channel. [7][8][17]
  - It was first recorded in Britain in August 1859, at Brighton and at Christchurch.
  - In 2015, about 60 adults crossed the Channel in August and laid thousands of eggs in gardens and allotments on the south coast.
  - Their young can emerge the same autumn, as they did in 2013, but they cannot survive the British winter.
  - Experts think a warming climate is behind more frequent arrivals, and models predict its range will spread north.
  - Long-tailed blue sightings in Britain: 1940–1988 85 sightings; 1945 alone 38 sightings; 1859–1939 36 sightings
- **Pod Borer** (6+ plant families on the caterpillar menu): The caterpillar feeds hidden inside flower buds and pods, which makes it a pest of pea and bean crops in many warm countries. [7][9][10][17]
  - Young caterpillars bore into buds through the petals, leaving only a tiny hole.
  - Older ones move into a pod and eat the seeds inside.
  - In India it attacks cowpea, pigeon pea, green gram, black gram and sunhemp. In southern Europe it can damage pea crops.
  - Cold winters limit where it can live, so warmer climates may let it spread further north.

### Body parts

- **Antennae** [1][2][3]
  - The real antennae grow from the head. They are black, ringed with white.
  - The thin tails at the back of the hindwings are thought to copy them, so a predator may mix up the front and the back.
- **Eyes** (360 nm ultraviolet seen by a copper relative) [4][5]
  - Blue butterflies (lycaenids) have an extra blue-sensitive pigment in their eyes, which may help them tell different blues apart.
  - In a related copper butterfly, the eyes hold four visual pigments, including one for ultraviolet light at 360 nm, which people cannot see.
  - In that species, males and females even have differently built eyes, matched to their different lives.
- **Proboscis** [6][7]
  - Adults drink nectar through a long tube called a proboscis, which stays coiled under the head when it is not in use.
  - Butterflies with a coiling proboscis can drink a steady column of liquid, or a chain of tiny bubbles that pulls up thin films of nectar.
  - In Britain, long-tailed blues are most often seen around garden flowers, especially plants their caterpillars can eat.
- **Forewings** (32–42 mm wingspan in UK guides) [1][4][7][8]
  - Males are violet-blue above with brown edges. Females are mostly brown, with shining blue scales near the wing bases.
  - In related blue butterflies, the male’s blue is a structural colour: tiny structures in the scales reflect blue light, rather than a blue pigment.
  - Those structures are so species-specific that a computer told nine blue species apart with more than 90% accuracy.
  - UK guides give a wingspan of 32–34 mm for males and 36–42 mm for females. Other sources give 24–34 mm.
- **Wing underside** [1][2]
  - Underneath, both sexes are grey-brown with many wavy brown lines edged with white.
  - The hindwing alone carries eight or nine wavy brown bands at even distances apart.
  - Lines that lead towards the tail end are one of the five features of a butterfly “false head”.
- **Tails and eyespots** (2 black eyespots by each tail) [1][7][2]
  - Each hindwing ends in a thin black tail tipped with white.
  - Beside each tail sit two small black eyespots with orange markings.
  - Together they look like a second head, with eyes and antennae, at the back of the butterfly.
  - At rest, the butterfly moves its hindwings, so the tails twitch.
- **Pea flower** (6+ plant families eaten by caterpillars) [1][9][8]
  - Females lay their eggs one at a time on the flower buds of peas, beans and their relatives.
  - Garden peas and broad beans are among the favourites. In Britain it also uses everlasting-peas, broom and bladder-senna.
  - Caterpillars have been found on plants from at least 6 families, but the pea family is by far the main one.
- **Caterpillar** (19 mm longest when fully grown) [7][9][10]
  - The flat, woodlouse-shaped caterpillar first eats flowers, then bores into a pod and eats the seeds inside.
  - It grows to about 16–19 mm and turns a dull lilac-pink just before it becomes a chrysalis.
  - After each moult except the first, it eats its old skin.
  - Ants often visit older caterpillars for sugary droplets.

### Stats

| Stat | Value | Notes |
|---|---|---|
| Wingspan | 32–42 mm | UK guides; females are larger. Other sources give 24–34 mm. [7][8][1] |
| Egg width | 0.5 mm | a flattened pale disc laid on a bud [7][1] |
| Egg to butterfly | 15–35 days | in studies in India and Bangladesh; slower in England [12][11][13][7] |
| Caterpillar length | 16–19 mm | fully grown, measured while crawling [7] |
| Caterpillar stages | 4 | instars, with a moult between each [11][13][7] |
| Adult life | 8–9.5 days | males and females in a lab study on field pea [11] |
| Host plant families | 6+ | the pea family is the main one [9] |
| Continents | 4 | Europe, Africa, Asia and Australia, plus islands such as Hawaii [9] |
| DNA difference | 0–0.5% | between most pea blues sampled more than 9,000 km apart [9] |
| First British record | 1859 | Brighton and Christchurch, August 1859 [7] |

### Photos

- [Long-tailed blue in Greece. The tails and eyespots at the back form the false head.](https://commons.wikimedia.org/wiki/File:Long-tailed_blue_(Lampides_boeticus)_Greece.jpg) (photo: Charles J. Sharp, CC BY-SA 4.0)
- [The wavy brown and white underside, photographed in the gardens of the Royal Palace of Caserta, Italy.](https://commons.wikimedia.org/wiki/File:Long-tailed_blue_(Lampides_boeticus)_underside_Italy.jpg) (photo: Charles J. Sharp, CC BY-SA 4.0)
- [A male basking with open wings, showing the violet-blue upperside.](https://commons.wikimedia.org/wiki/File:Open_Wing_Basking_Position_of_Lampides_boeticus_(Linnaeus%2C_1767)_-_Pea_Blue_2.jpg) (photo: Bias Chakraborty, CC BY-SA 4.0)
- [Male upperside, Genova, Italy.](https://commons.wikimedia.org/wiki/File:Lycaenidae_-_Lampides_boeticus_(male).JPG) (photo: Hectonichus, CC BY-SA 4.0)
- [Female in Andalucia, Spain: brown above with blue near the wing bases.](https://commons.wikimedia.org/wiki/File:Female_Long-tailed_Blue._Lampides_boeticus_(31966803250).jpg) (photo: gailhampshire from Cradley, Malvern, U.K, CC BY 2.0)
- [A pea blue caterpillar in Maharashtra, India. Its flat, woodlouse-like shape is typical of blue butterflies.](https://commons.wikimedia.org/wiki/File:Lampides_boeticus_%E2%80%93_Pea_Blue_Larva_(1).jpg) (photo: Milind Bhakare, CC BY-SA 4.0)
- [Sipping nectar with wings closed.](https://commons.wikimedia.org/wiki/File:Close_wing_nectaring_position_of_Lampides_boeticus_(Linnaeus%2C_1767)_-_Pea_Blue.jpg) (photo: B Savit, CC BY-SA 4.0)
- [A pea blue in Osaka, Japan, at the far end of its range from Britain.](https://commons.wikimedia.org/wiki/File:Peablue_October_2007_Osaka_Japan.jpg) (photo: Laitche, Public domain)
- [Lang’s short-tailed blue, Portugal: smaller, with a striped underside and short tails.](https://commons.wikimedia.org/wiki/File:Lang's_short_tail_blue_(Leptotes_pirithous)_male_underside.jpg) (photo: Charles J. Sharp, CC BY-SA 4.0)

### Questions

- **Is the pea blue butterfly a pest?** Its caterpillars eat flowers and the seeds inside the pods of peas, beans and other legumes, so it is a pest of pulse crops such as cowpea and pigeon pea in many warm countries. In southern Europe it can damage pea crops. [9][10][7]
- **Why is it called the long-tailed blue?** Because of the long, thin tail on each hindwing, which flutters in the breeze. The name pea blue comes from its favourite food plants and the male’s blue colour. [8][1]
- **Does the long-tailed blue live in the UK?** Not all year. It is a rare migrant from the Mediterranean, seen mostly in late summer in southern England. Migrants can breed here, but the species cannot survive British winters. [8][7]
- **Why do ants look after pea blue caterpillars?** The caterpillars give ants sugary droplets from special glands. In return, ants may protect them from enemies. The pea blue can also survive without ants. [9][14][15][16]
- **What is a false head on a butterfly?** A pattern at the back of the hindwings that looks like a head: tails as antennae, eyespots as eyes and lines that lead to them. Scientists think it makes predators attack the wrong end, but the evidence is still limited. [2][3]
- **How long does a pea blue butterfly live?** In warm countries it takes about 15–35 days to go from egg to butterfly. In a lab study, adult males lived about 8 days and females about 9.5 days. [12][11]
- **How can you tell a male from a female pea blue?** Look at the upperside: males are violet-blue with brown edges, females are mostly brown with a little blue near the body. Underneath, both look the same. [1]
- **What is the difference between the long-tailed blue and Lang’s short-tailed blue?** The long-tailed blue is bigger (32–42 mm in UK guides) with one long tail per hindwing and wavy underside lines. Lang’s short-tailed blue is smaller (26–34 mm), with two small tails and a striped underside. [7][18][1][19]

### Pea blue myths and facts

Some things people say about pea blues are true. Some are not. Tap to check.

- "Pea blues are blue all over." **Myth!** Only the male’s upperside is violet-blue. Females are mostly brown above, and both sexes are grey-brown with wavy lines underneath. [1]
- "The tails on its wings are its real antennae." **Myth!** The real antennae grow from the head and are black ringed with white. The tails at the back of the hindwings are thought to imitate them. [1][2]
- "The false head saves pea blues from predators." **Not proven!** Scientists think it helps, and small experiments with other false-head butterflies support the idea. But in a mantis test, clipping the tails made no difference, so more research is needed. [3][2]
- "Pea blue caterpillars are looked after by ants." **Fact!** Many kinds of ants visit them for sugary droplets, from carpenter ants to the Argentine ant. The caterpillars can also live without ants. [9]
- "The pea blue is one of Hawaii’s native butterflies." **Myth!** Pea blues live in Hawaii today, but Hawaii has only two native butterflies: the Kamehameha butterfly and the Koa butterfly. [9][21]
- "Long-tailed blues live in Britain all year round." **Myth!** It is a rare migrant. Arrivals can breed in summer and autumn, but the species cannot survive British winters. [7][8]
- "Its caterpillars can damage pea and bean crops." **Fact!** They eat flowers and the seeds inside pods, and are a pest of pulses such as cowpea and pigeon pea in many warm countries. [9][10][7]
- "The male’s blue comes from a blue pigment." **Myth!** Studies of related blue butterflies show the blue is a structural colour: tiny structures in the wing scales reflect blue light. [4]

### Pea blue records

Superlatives backed by measurements and records.

- One of the most widespread butterflies: Pea blue, 4 continents (from Britain to Japan, across Africa, southern Asia and Australia, and out to Hawaii) [9]
- Same butterfly, far apart: Pea blue, 0–0.5% (DNA difference between most pea blues sampled more than 9,000 km apart) [9]
- Alone in its genus: Lampides boeticus, 1 species (the genus Lampides has no other species and no commonly accepted subspecies) [9]
- Quickest life cycle we found: Pea blues in southern India, 15 days (the shortest egg-to-adult time in a study in Kadapa, India (15–22 days)) [12]
- First seen in Britain: Brighton and Christchurch, 1859 (the first British records, both in August 1859) [7]
- Biggest early British arrival: Summer 1945, 38 sightings (the only major arrival recorded before recent decades) [7]

### A pea blue’s life

From egg to butterfly in a few weeks. Times are from studies in warm countries and from England.

- **Day 0**: An egg on a bud. A female lays a single pale egg, about 0.5 mm wide, on a flower bud of a pea, bean or relative. [1][7]
- **Days 2–7**: Hatching. The caterpillar, under 1 mm long, eats a round hole in its eggshell and bores into a bud. [12][7]
- **Next 1–4 weeks**: Flowers, then pods. Over four stages it grows to about 16–19 mm, moving from flowers into a pod to eat the seeds. [11][7]
- **Older caterpillar**: Ant visitors. Ants often visit the older caterpillars for sugary droplets. [10][9]
- **Fully grown**: Lilac-pink. The caterpillar turns a dull lilac-pink and gets ready to pupate. [7]
- **3–10 days**: Chrysalis. The chrysalis, about 1 cm long, is held by a silk girdle. It lasts 3–8 days in India and about 10 days in England. [12][11][7]
- **2–5 weeks after the egg**: Butterfly. The adult emerges and drinks nectar. In a lab study, adults lived about 8–9.5 days. [12][11]
- **Late summer in Britain**: Migrants arrive. Migrants from the south are seen mostly from late July to September. Their young cannot survive the winter. [7]

### Pea blue vs Lang’s short-tailed blue vs common blue

Three small blue butterflies that can turn up in the same gardens, side by side.

| | Pea blue | Lang’s short-tailed blue | Common blue |
|---|---|---|---|
| Scientific name [20] | Lampides boeticus | Leptotes pirithous | Polyommatus icarus |
| Wingspan (UK guides) [7][18][22] | 32–42 mm | 26–34 mm | 29–36 mm |
| Tails [1][19] | One long, thin tail per hindwing | Two small tails | — |
| Underside [1][19] | Wavy brown lines edged with white | Striped (also called common zebra blue) | — |
| Caterpillar food [8][9][19][23] | Peas, beans, broom and other legumes | Legumes, plumbago and other plants | Mainly bird’s-foot trefoil |
| In Britain [7][18][23] | Rare migrant | Rare migrant | Resident; the most widespread blue |
| Ants [9][22] | Tended by many ant species | — | Last-stage caterpillars and pupae attract ants |
| IUCN status [20] | Least Concern | Least Concern | Not evaluated globally |

“—” means we found no reliable source to compare. Wingspans are from UK Butterflies; other guides give smaller ranges.

### Is the pea blue endangered?

No. The pea blue is common across a huge range and is even a crop pest in places.

- **IUCN Red List:** Least Concern (LC) (Population stable). Listed as Least Concern because it is common across a huge range. Butterfly Conservation lists its European status as stable. [24][20][25][8]
- IUCN Red List, 2020 assessment
- **Threat: Cold winters**: The temperature of the coldest month limits where it can live, and it cannot survive British winters. [17][7]
- **Threat: Treated as a pest**: Because its caterpillars damage pulse crops, farmers in many warm countries try to control it. [10][17]
- **Helping: Garden legumes**: Everlasting-peas, broom, bladder-senna and mange-tout peas in gardens and allotments give migrants places to breed. [8]
- **Helping: A warmer climate**: Experts think climate change is behind more frequent arrivals in Britain, and models predict its range will spread north. [8][17]
- **Helping: Recording sightings**: Records of sightings since 1859 show how arrivals in Britain have changed over time. [7]
- **Lang’s short-tailed blue** (LC): Also Least Concern; a regular migrant in southern Europe, Africa and Asia. [20][19]

### Pea blue signals

- Hindwings rotating, tails twitching: Resting and on guard: the moving tails may pull a predator’s attention to the fake head. [7][3]
- Fluttering around pea and bean flowers: Often a female looking for flower buds to lay eggs on, one at a time. [7][1]
- Ants gathered on a caterpillar: The caterpillar is giving them sugary droplets; ants may protect it in return. [9][16]
- Caterpillar turning lilac-pink: It is fully grown and about to become a chrysalis. [7]

### Forms

- **Male**: Violet-blue upperside with brown edges and fine whitish hairs; grey-brown wavy underside; thin tails with eyespots. (The form most people notice) [1]
- **Female**: Mostly brown above, with shining blue scales near the wing bases and dark spots by the tails. The underside matches the male’s. (Lays eggs one at a time on flower buds) [1]
- **Caterpillar with ant**: A flat, woodlouse-shaped caterpillar up to about 19 mm long, often visited by ants. It turns dull lilac-pink just before it pupates. (Feeds in the flowers and pods of legumes) [7][9]
- **Lang’s short-tailed blue**: Smaller (26–34 mm), with two small tails and a striped underside that gives it its other name, common zebra blue. (Least Concern; a migrant across southern Europe and Africa) [18][19][20]

### Pea blue quiz

1. Where is the pea blue’s “false head”? **At the back of the hindwings.** Tails and eyespots at the back of the hindwings look like a second head. [1][2]
2. What are the hindwing tails thought to imitate? **Antennae.** The thin tails are thought to copy the antennae on the real head. [2][1]
3. What colour is the upperside of a male pea blue? **Violet-blue.** Males are violet-blue above; females are mostly brown. [1]
4. Where does a female lay her eggs? **One at a time on flower buds.** Eggs are laid singly on the flower buds of legumes. [1][7]
5. About how wide is a pea blue egg? **0.5 mm.** The egg is a flattened disc about 0.5 mm across. [7][1]
6. Where do older caterpillars feed? **Inside pea and bean pods.** They bore into pods and eat the seeds inside. [7]
7. Why do ants visit pea blue caterpillars? **For sugary droplets.** The caterpillars reward ants with sugary food from special glands. [9][15]
8. About what share of lycaenid butterflies associate with ants? **About three-quarters.** About three-quarters of lycaenids associate with ants as caterpillars or pupae. [9]
9. When was the long-tailed blue first recorded in Britain? **1859.** In August 1859, at Brighton and Christchurch. [7]
10. In 2015, about how many adults crossed the Channel to England? **60.** About 60 adults arrived in August and laid thousands of eggs. [8]
11. How long can it take to go from egg to butterfly in warm countries? **15–35 days.** Studies in India and Bangladesh measured about 15–35 days. [12][11]
12. What makes the blue colour of male blue butterflies? **Tiny structures in the wing scales.** It is a structural colour: tiny structures in the scales reflect blue light. [4]

### Sources (checked 2026-10-16)

1. [Wikipedia contributors. Lampides boeticus. Wikipedia, The Free Encyclopedia.](https://en.wikipedia.org/wiki/Lampides_boeticus)
2. [Yumnam T, Kodandaramaiah U (2025). Correlated evolution of multiple traits gives butterflies a false head. Proceedings of the Royal Society B 292:20250900.](https://doi.org/10.1098/rspb.2025.0900)
3. [López-Palafox TG, Cordero CR (2017). Two-headed butterfly vs. mantis: do false antennae matter? PeerJ 5:e3493.](https://doi.org/10.7717/peerj.3493)
4. [Bálint Z, Kertész K, Piszter G, Vértesy Z, Biró LP (2012). The well-tuned blues: the role of structural colours as optical signals in the species recognition of a local butterfly fauna (Lepidoptera: Lycaenidae: Polyommatinae). Journal of the Royal Society Interface 9:1745–1756.](https://doi.org/10.1098/rsif.2011.0854)
5. [Sison-Mangus MP, Bernard GD, Lampel J, Briscoe AD (2006). Beauty in the eye of the beholder: the two blue opsins of lycaenid butterflies and the opsin gene-driven evolution of sexually dimorphic eyes. Journal of Experimental Biology 209:3079–3090.](https://doi.org/10.1242/jeb.02360)
6. [Palaoro AV, Monaenkova D, Beard CE, Adler PH, Kornev KG (2024). Biomechanical drivers of the evolution of butterflies and moths with a coilable proboscis. Proceedings of the Royal Society B 291:20240903.](https://doi.org/10.1098/rspb.2024.0903)
7. [Eeles P. UK Butterflies: Long-tailed Blue, Lampides boeticus (with life-history notes quoted from Frohawk 1924).](https://www.ukbutterflies.co.uk/species.php?species=boeticus)
8. [Butterfly Conservation. Long-tailed Blue (species page).](https://butterfly-conservation.org/butterflies/long-tailed-blue)
9. [Lohman DJ, Peggie D, Pierce NE, Meier R (2008). Phylogeography and genetic diversity of a widespread Old World butterfly, Lampides boeticus (Lepidoptera: Lycaenidae). BMC Evolutionary Biology 8:301.](https://doi.org/10.1186/1471-2148-8-301)
10. [Sontakke P (2018). Life cycle of the pulse blue butterfly, Lampides boeticus (Linnaeus) (Lepidoptera: Lycaenidae) on cowpea. International Journal of Current Microbiology and Applied Sciences 7:2377–2381.](https://doi.org/10.20546/ijcmas.2018.702.290)
11. [Manisha, Verma, Kumar, Lal (2020). Biology of blue butterfly Lampides boeticus (L.) on field pea. Indian Journal of Entomology 82:830–832.](https://doi.org/10.5958/0974-8172.2020.00152.2)
12. [Palem (2015). Eco biology and life cycle of the pea blue butterfly, Lampides boeticus (Linnaeus) (Lepidoptera: Rhopalocera: Lycaenidae). South Asian Journal of Life Sciences 3:14–21.](https://doi.org/10.14737/journal.sajls/2015/3.1.14.21)
13. [Miah, Akand, Parven, Bashar (2015). Developmental stages of Lampides boeticus (Lepidoptera: Lycaenidae) and their association with the host plant Lupinus nanus (Fabaceae). Dhaka University Journal of Biological Sciences 24:43–52.](https://doi.org/10.3329/dujbs.v24i1.46307)
14. [Pierce NE, Braby MF, Heath A, Lohman DJ, Mathew J, Rand DB, Travassos MA (2002). The ecology and evolution of ant association in the Lycaenidae (Lepidoptera). Annual Review of Entomology 47:733–771.](https://doi.org/10.1146/annurev.ento.47.091201.145257)
15. [Pierce NE, Dankowicz E (2022). Behavioral, ecological and evolutionary mechanisms underlying caterpillar-ant symbioses. Current Opinion in Insect Science 52:100898.](https://doi.org/10.1016/j.cois.2022.100898)
16. [Mizuno T, Hagiwara Y, Akino T (2019). Varied effects of tending ant species on the development of facultatively myrmecophilous lycaenid butterfly larvae. Insects 10:234.](https://doi.org/10.3390/insects10080234)
17. [Hwang JH, Yoon S, Lee WH (2025). Evaluation of spatial distribution of pulse blue butterfly (Lampides boeticus), pest of legume crops, in response to climate change. Insects 16:826.](https://doi.org/10.3390/insects16080826)
18. [Eeles P. UK Butterflies: Lang's Short-tailed Blue, Leptotes pirithous.](https://www.ukbutterflies.co.uk/species.php?species=pirithous)
19. [Wikipedia contributors. Leptotes pirithous. Wikipedia, The Free Encyclopedia.](https://en.wikipedia.org/wiki/Leptotes_pirithous)
20. [GBIF Species API. IUCN Red List categories: Lampides boeticus (LC), Leptotes pirithous (LC), Polyommatus icarus (not evaluated globally).](https://api.gbif.org/v1/species/1924713/iucnRedListCategory)
21. [Wikipedia contributors. Udara blackburni. Wikipedia, The Free Encyclopedia.](https://en.wikipedia.org/wiki/Udara_blackburni)
22. [Eeles P. UK Butterflies: Common Blue, Polyommatus icarus.](https://www.ukbutterflies.co.uk/species.php?species=icarus)
23. [Butterfly Conservation. Common Blue (species page).](https://butterfly-conservation.org/butterflies/common-blue)
24. [Edge DA, Westrip JRS (2020). Lampides boeticus. The IUCN Red List of Threatened Species 2020.](https://doi.org/10.2305/IUCN.UK.2021-1.RLTS.T174427A161341394.en)
25. [Wikidata. Lampides boeticus (Q929463): taxon name, IUCN status Least Concern (P141), IUCN taxon ID 174427.](https://www.wikidata.org/wiki/Q929463)

## Measurements & details

- **Length:** 1-2 cm
- **Wingspan:** 2.4-4.2 cm
- **Weight:** 0.0001-0.0003 kg
- **Lifespan:** up to 1 years
- **Clutch Size:** 1-10
- **Incubation:** 2-7 days

## Diet & Feeding

Caterpillars feed mostly on the flowers and seed pods of leguminous plants, while adults forage for floral nectar.

- **Age differences:** Larvae consume solid plant material, specifically targeting nitrogen-rich reproductive parts of legumes, whereas adults exclusively consume liquid nectar.
- **Primary Foods:** Legume flowers, Pea pods, Bean pods, Broom flowers, Alfalfa
- **Foraging Method:** Foraging

## Ecological connections

- **Host plant:** Garden Pea (*Pisum sativum*) — Host plant for laying eggs and caterpillar feeding.
- **Mutualism:** Carpenter Ants (*Camponotus*) — Ants visit the caterpillars for sugary droplets and may protect them in return.

## Safety

**Danger:** 1/5 · Very low

No special safety notes yet.

## Frequently Asked Questions

### How to identify Pea Blue?

Compare the wing outline, spots, bands, eyespots and wing edges. The underside can look completely different from the top. Check for tails, the antennae and where the markings sit instead of relying on color alone. Butterfly Identifier: upload a photo and compare the visible details.

### How long is Pea Blue?

1-2 cm

### What is Pea Blue's wingspan?

2.4-4.2 cm

### How much does Pea Blue weigh?

0.0001-0.0003 kg

### How long does Pea Blue live?

up to 1 years

### What does Pea Blue eat?

Caterpillars feed mostly on the flowers and seed pods of leguminous plants, while adults forage for floral nectar.

### Where is Pea Blue usually found?

Found in open woodlands, agricultural fields, meadows, and urban gardens, typically wherever leguminous host plants are abundant.

## Where to spot

- [Puna-Ka'u Historic District](https://www.snappit.app/guides/places/puna-kau-historic-district) — Hawaii, US · Historic District
- [Sierra Nevada National Park](https://www.snappit.app/guides/places/sierra-nevada-national-park) — Andalusia, ES · National Park

## More Insects

- [Common Eastern Bumble Bee](https://www.snappit.app/explore/common-eastern-bumble-bee) (*Bombus impatiens*)
- [Spotted Lanternfly](https://www.snappit.app/explore/spotted-lanternfly) (*Lycorma delicatula*)
- [Brown-belted Bumble Bee](https://www.snappit.app/explore/brown-belted-bumble-bee) (*Bombus griseocollis*)
- [Eastern Carpenter Bee](https://www.snappit.app/explore/eastern-carpenter-bee) (*Xylocopa virginica*)

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Source: [Pea Blue: Characteristics, Facts & Places to See — Snappit](https://www.snappit.app/explore/pea-blue)