Discovery of a peculiar insular race of Ravenna nivea (Nire, 1920) (Lepidoptera: Lycaenidae) endemic to Yinggeling Mountain of Hainan, suggesting heterogeneous geological history of mountain formation of the island.

A peculiar population of Ravenna nivea (Nire, 1920) was discovered from the Yinggeling Mountain Mass of central Hainan. Its wing pattern and COI barcode data show considerable distinction from other geographic populations of R. nivea, including that of Bawangling, approximately only 40 km away and also located in Hainan. The p-distance value of the COI barcode between the Yinggeling and Bawangling populations was 1.1%, considerably higher than the value (0.6%) between Bawangling population and populations in eastern China, where the subspecific name howarthi Saigusa, 1993 applies. The population is regarded as a distinct subspecies ngiunmoiae Lo & Hsu, subsp. nov. The distinctness and high degree of COI haplotype diversity of R. nivea found in Hainan and Taiwan suggest continental islands may serve as glacial refugees for the butterfly and other organisms during previous glaciations, and the presence of the relict populations of montane butterflies like R. nivea may provide useful clues towards a better understanding of the geological history of mountain formation within islands.

Notes on Halpe paupera Devyatkin, 2002 (Lepidoptera: Hesperiidae).

A series of specimens with some differences in wing patterns and male genitalia from different localities is recognized as Halpe paupera Devyatkin, 2002 by comparing the COI gene sequences. The morphological variability in male is discussed and illustrated. The intraspecific variation of the female of H. paupera walthewi Devyatkin, 2002 from the type locality is elucidated, and hence this subspecies is considered a synonym of H. paupera paupera. A distribution map and some bionomic information of the species are provided.

On a New Insular Subspecies of Chrysozephyrus mushaellus (Matsumura) (Lepidoptera: Lycaenidae) Discovered from Hainan.

Chrysozephyrus mushaellus paolongkoui, ssp. nov. is described and illustrated from Hainan island of southern China. This new subspecies possesses diagnosable characters different from previously recognized subspecies of C. mushaellus in wing marking and genitalia of both sexes. It utilizes Lithocarpus litseifolius (Fagaceae) as the larval hostplant.

First use of artificial canopy bridge by the world's most critically endangered primate the Hainan gibbon Nomascus hainanus.

All gibbon species (Primates: Hylobatidae) are facing high extinction risk due to habitat loss and hunting. The Hainan gibbon Nomascus hainanus is the world's most critically endangered primate, and one of the priority conservation actions identified is to establish artificial canopy corridors to reconnect fragmented forests. The effectiveness of artificial canopy bridge as a conservation tool for wild gibbons has not been widely tested, and the results are rarely published. We constructed the first canopy bridge for Hainan gibbon in 2015 to facilitate passage at a natural landslide; mountaineering-grade ropes were tied to sturdy trees with the help of professional tree climbers and a camera trap was installed to monitor wildlife usage. Hainan gibbon started using the rope bridge after 176 days, and usage frequency increased with time. All members in the gibbon group crossed the 15.8 m rope bridge except adult male. Climbing was the predominant locomotor mode followed by brachiation. This study highlights the use and value of rope bridges to connect forest gaps for wild gibbons living in fragmented forests. While restoring natural forest corridors should be a priority conservation intervention, artificial canopy bridges may be a useful short-term solution.

A new subspecies of Delias agostina Hewitson (Lepidoptera: Pieridae: Pierinae) from Hainan Island.

The taxonomic status of the population of Delias agostina on Hainan Island is clarified and previous taxonomic treatments are reviewed. The insular population is found distinctive from continental races and is described herein as, Delias agostina sushii ssp. nov., a new subspecies endemic to Hainan Island. Notes on immature stages of the new taxon are also provided.

Description of a new subspecies of Talicada nyseus (Guérin-Méneville, 1843) from Hainan, China (Lepidoptera: Lycaenidae), with notes on the genus Talicada Moore, 1881.

An insular population of Talicada nyseus was discovered from Hainan Island, representing a butterfly species unrecorded in China. Materials of this species from Hainan were compared with the races from other regions, revealing that the wing pattern is distinct from that of other subspecies, and is hereinto described as T. nyseus lami ssp. nov.. Information on immature stage and host association of the new subspecies, and notes on the genus is also provided.

A taxonomic note on Erionota acroleuca (Wood-Mason & de Nicéville, 1881) stat. rest. (Lepidoptera: Hesperiidae).

The purpose of this paper is to restore Erionota acroleuca (Wood-Mason & de Nicéville, 1881) as a valid name, and to establish Erionota acroleuca apicalis de Jong & Treadaway, 1992 as a new subspecific combination, with its immature biology briefly introduced.