Exema mormona

Members of Exema can be distinguished from the related genus Neochlamisus by their smaller size (2–3 mm versus 3–4 mm). Like other Chlamisini, E. mormona exhibits the characteristic frass-mimicry morphology: a compact, irregularly rounded body with a rough, warty surface texture. When disturbed, the beetle retracts its head and folds its legs and antennae into precisely matched grooves, eliminating any visible indication of being an insect. The coloration is variable and may include metallic sheens that enhance the resemblance to caterpillar excrement.

Recorded from North America. Specific locality data beyond this continental-level occurrence is not available in the provided sources.

Has been observed exhibiting the characteristic defensive behavior of Chlamisini: upon disturbance, retracting the head and folding legs and antennae into body grooves to achieve complete resemblance to inanimate caterpillar frass. This behavior may cause the beetle to roll off the substrate, facilitating escape from predators.

• NeochlamisusLarger congeneric warty leaf beetles (3–4 mm versus 2–3 mm in Exema); both genera share the frass-mimicry morphology and defensive limb-retraction behavior
• Other ChlamisiniAll members of the tribe share the characteristic compact, warty body form and frass-mimicry defensive strategy, though Exema is distinguished by its smaller size and specific genus-level characters

• warty leaf beetle
• frass mimicry
• Chlamisini
• Cryptocephalinae
• caterpillar excrement mimicry
• defensive behavior
• case-bearing larvae

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