Native across the Palaearctic and introduced in North America and New Zealand.
Fine-art photographic collection
Cassida (Cassida) rubiginosa
A beetle larva that carries an adjustable shield made from its own waste.
About this species
Green Thistle Beetle
Cassida (Cassida) rubiginosaMüller, 1776
Information reviewed15 July 2026
The thistle tortoise beetle’s larva builds one of the most remarkable portable defences among insects. A fork at the rear of the body supports a packet assembled from cast skins and faeces.
Taxonomy
Animalia · Arthropoda · Insecta · Coleoptera · Chrysomelidae · Cassida
GBIF/Catalogue of Life accepts Cassida (Cassida) rubiginosa Müller, 1776; English common name follows that record. · checked 2026-07-15
Palaearctic and introduced regionsBroad documented range and selected reference localities — not a complete occurrence map.
Grassland, field margins, disturbed ground and gardens where thistles grow.
Adults and larvae are active on host plants during the growing season.
Feeds mainly on thistles and related Asteraceae.
Solitary.
What makes this species remarkable?
The larva raises and pivots its faecal shield towards an attacker, using it as a movable barrier rather than passive camouflage.
Experiments showed that the shield is highly effective at physically blocking the bites of attacking ants.
The species also carries a specialised gut symbiont that helps break down pectin in tough plant cell walls.