Müllerian mimicry between cohabiting final-instar larval Pryeria sinica Moore, 1877 (Lepidoptera: Zygaenidae) and pupal Ivela auripes (Butler, 1877) (Lepidoptera: Lymantriidae)

Abstract

The final-instar larvae of Pryeria sinica Moore, 1877 (Zygaenidae) are conspicuously colored yellow-green with black stripes and are known to escape from attacks after predators learn of the cyanogenic fluids secreted on their body surface. Ivela auripes (Butler, 1877) (Lymantriidae) is often found in the same habitat during the same season as P. sinica, and its pupa (not larva) is similar to larval P. sinica in shape and color. Mature larvae of P. sinica search for pupation sites during the daytime and pupate in cryptic, pale-brown cocoons. On the other hand, I. auripes pupates without cocoons on substrates near and above the ground, where they appear to be exposed to predators. In this study, it was observed that Japanese tits, Parus minor Temminck & Schlegel, 1848, ate I. auripes pupae attached to a wall, but no tit individual ever attacked them repeatedly. When fed pupae or larvae in the laboratory, Japanese grass lizards, Takydromus tachydromoides (Schlegel, 1838), rarely ate larval P. sinica or pupal I. auripes or regurgitated them soon after eating them, suggesting their unpalatability. If discrimination of pupal I. auripes from larval P. sinica is not precise for these potential predators, their similar warning colors might constitute a rare case of Mullerian mimicry between different developmental stages of unrelated moth species.