Immature biology of Prosotas reveals an ovipositing strategy unusual in polyommatine lycaenids (Lepidoptera: Lycaenidae: Polyommatinae), with a description of a new subspecies of P. dubiosa from Taiwan

The immature biology of a widespread and often-abundant lycaenid in the genus Prosotas was heretofore poorly documented. Investigations conducted on 2 widely distributed and largely sympatric species, P. nora and P. dubiosa, revealed that both species exhibit peculiar oviposition behaviors. The females oviposit in the host inflorescence only during a critical development stage of the inflorescence. Their ova are laid within tightly arranged flower buds and are concealed with a transparent gelatinous substance, rendering the ova cryptic. Due to this peculiar behavior, host choice by Prosotas obviously requires a suitable inflorescence type in addition to appropriate chemical stimuli of potential host plants. In association with this ovipositional behavior, larvae of both species exit the ovum or ova laterally rather than in the usual way from the top. The papillae anales of the female genitalia are produced posteriad and show a modification to facilitate oviposition. The ovipositional behavior and lateral eclosion of the larvae are considered potential synapomorphies of the genus Prosotas as they are unique among polyommatine lycaenids. A discussion on earlier misconceptions concerning the immature biology of Prosotas is provided. Finally, samples of P. dubiosa from Taiwan were compared with those from other regions, revealing that they consistently differ from those of other regions, and thus they are described as P. dubiosa asbolodes, ssp. nov.