Madagascan Comet Moth

Argema mittrei — the Madagascan comet moth, also called the moon moth — is one of the most spectacular moths on Earth and the species with the longest wing tails of any moth ever measured. The species is endemic to Madagascar's eastern rainforests. Adults are 20 cm wingspan with brilliant golden-yellow wings (males more saturated than females) carrying single dramatic eye-spots on each wing and dramatically extended hindwing tails — males have tail filaments up to 15 cm long, giving the species the appearance of a small comet in flight (the source of the common name). Females have shorter tails (~6-8 cm). Like all giant silk moths (family Saturniidae — atlas, luna, hercules, polyphemus), the comet moth adult has no functional mouthparts and lives just 4-5 days on caterpillar-stored fat reserves; the entire purpose of adult life is finding a mate. The species' long wing tails were historically interpreted as purely sexually-selected ornaments — male tails are longer than female tails, suggesting display function in mate evaluation. But Barber et al. (2015, PNAS) demonstrated experimentally that the long tails ALSO function as BAT SONAR DEFLECTORS: the trailing filaments return echolocation pulses to attacking bats with confusing acoustic signatures (the tail returns and the body returns reach the bat at slightly different times and from slightly different directions), throwing off the bat's targeted strike. Moth species with long tails experience approximately 50% lower bat predation than tail-less control species. The dual function (sexual display + acoustic deflection) makes the comet moth tail one of the most-cited examples of multi-functional sexually-selected traits in evolutionary biology. Caterpillars feed on multiple Madagascan endemic tree species and develop over 2-3 months before pupation in elaborate silk cocoons. The species is a flagship of Madagascan endemic biodiversity and one of the most-photographed moths in the world.