Gram blue
Gram blue caterpillars feed inside the pods and flowers of wild legumes and can become a minor pest of cultivated cowpea across tropical Asia.
| Where | Weedy farmland, wastelands and gardens |
|---|---|
| Size | 20 to 26 mm wingspan |
| When | January to December |
The gram blue is a small, delicate butterfly with a pair of fine, thread-like tails on each hindwing. Males show a pale purplish blue upperside, while females are duller with brown-bordered wings and larger, orange-crowned spots near the tail; the underside is pale buff with neat rows of small brown, white-edged spots.
Caterpillars feed on the young leaves, flowers and seed pods of legumes such as cowpea and tropical kudzu, and adults bask with wings open on sunny mornings and evenings before visiting weedy flowers for nectar.
Traits
Habitat
Farmland
Colour
Blue, Brown, Orange
Active
Day
To people
Not known to bite or sting; caterpillars occasionally feed on cultivated cowpea pods.
Activity through the year
Often confused with
Underside marked with sinuous brown streaks and a broad pale bar, rather than the neat rows of small spots seen on the gram blue's underside.
Questions
Is the Gram blue dangerous to people?
Not known to bite or sting; caterpillars occasionally feed on cultivated cowpea pods.
When can you see the Gram blue?
The Gram blue can be seen from January to December, by day.
Plate retouched from a museum specimen photo by Finnish Museum of Natural History - Zoology Unit, CC BY 4.0, GBIF Licence
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Butterflies and moths›Blues and coppers›Euchrysops
Last updated 2026-09-27. Every entry is checked against published sources.