Alurnus orbignyi is a species of beetle of the family Chrysomelidae. It is found in Argentina, Bolivia, Brazil, Ecuador, Peru and Venezuela.
Adults reach a length of about 28âÂÂ37 mm. Adults have a shining black head and legs, while the pronotum is reddish with a black basal spot. The elytron is pale yellow with a black spot.
They have been recorded feeding on Aroides species.