Influence of plant on distribution of an endangered butterfly, Leptalina unicolor (Bremer & Grey, 1853), in restored riverside areas along the Geum River

Abstract

Background: The dramatic worldwide decline in the butterfly species Leptalina unicolor (Bremer & Grey) is largely the result of continuous habitat decline and disturbance by humans. The discovery of a narrow habitat in riverside wetlands utilized by L. unicolor raises the hope that such restricted key areas could be rather easily protected. Results: Here, we explain the environmental variables and habitat characteristics that primarily influence the distribution of L. unicolor discovered at the riverside areas along the Geum River. L. unicolor larvae were found at 9 of 13 study sites, and their abundance was strongly positively correlated with plant biomass. Our investigation showed that among four plant species (Miscanthus sinensis, Spodiopogon cotulifer, Setaria viridis, and Imperata cylindrica), L. unicolor larvae were the most abundant on the leaves of M. sinensis. They were not abundant on the leaves of S. cotulifer, S. viridis, or I. cylindrica. Interestingly, the number of L. unicolor larvae was positively correlated with the coverage area (m 2 ) of M. sinensis (F = 41.7, r 2 = 0.74, P < 0.0001).Conclusions: It appears that water (e.g., wetlands, ponds, and watersides) located along the riverside areas along the Geum River is important for the constant maintenance and conservation of L. unicolor. This is based on the habitat characteristics (water preference) of M. sinensis, which is used as a habitat by L. unicolor larvae. However, the waterside is dry and terrestrialization is in progress owing to the decreased water levels and water supply caused by an opened weir. Hereafter, this area will likely require management to secure a stable habitat for L. unicolor.

Potential distribution of the silver stripped skipper (Leptalina unicolor) and maiden silvergrass (Miscanthus sinensis) under climate change in South Korea

“…In South Korea, small populations have been identified in areas, such as Miryang‐si (Jeyak Mountain), Inje‐gun (Simjeok Wetland), and Buyeo‐gun (Geum River) (Choi et al . 2019). It is recognized as an endangered species according to the Korean Red List of Threatened Species (NIBR 2014).…”

“…A study showed that 13 plant species, including Salix koreensis , Lespedeza cuneata , Paspalum distichum , and Festuca arundinacea , host L. unicolor (Choi et al . 2019). However, M. sinensis is the principal host of this butterfly.…”

“…In South Korea, small populations have been found in the eastern, western, northeastern regions and their major habitat is grasslands near rivers and wetlands (Choi et al . 2019).…”

“…2020; Nakamura 2011) and evaluated as an endangered species in South Korea (Choi et al . 2019; NIBR 2014). Increased temperature has an impact on the metamorphosis and breeding behaviors of L. unicolor , including oviposition and larval and pupal development (Davis et al .…”

“…Studies have shown that the larvae of L. unicolor are abundant in plant communities dominated by M. sinensis (Choi et al . 2019). The shape and structure of M. sinensis provides a favorable habitat for L. unicolor .…”