Landscape Heterogeneity and Changing Bioclimatic Parameters Link to Potential Expansion of Gazalina chrysolopha (Lepidoptera; Notodontidae) in Nepal: A Possible Bioagent for Seasonal Hyperacute Panuveitis (SHAPU) in South Asia

Abstract

Seasonal hyperacute panuveitis (SHAPU) is an eye disease primarily reported in Nepal, especially in mid-hill regions of central and western parts. Several clinical and entomological studies have identified Gazalina chrysolopha as the possible causative agent for this disease. This study aimed to identify how the landscape structure and bioclimatic factors are shaping its distribution in the Nepal Himalayas. We performed extensive surveys in various regions of Nepal, focusing on previous and current SHAPU-reported sites in the country. We performed extensive observations in all possible habitats across the sites, and records were made with GPS points indicating the presence of adult moths. The surveys were conducted from March to October over two consecutive years: March 2023 to October 2024. We supplied the presence GPS points with freely available bioclimatic, topographic, vegetation, and landscape-related variables to model habitat suitability and to predict both current and future distributions of G. chrysolopha using the Maxent algorithm. Our analysis indicated that landscape heterogeneity combined with bioclimatic parameters is a major determinant of the spatial distribution of this species of moth in Nepal. Our study found that the moth exhibits a higher population presence in the mid-mountains of Nepal. Our model predicted that the eastern part of Nepal has a higher probability of habitat suitability for this species under scenarios of climate and rapid landscape change. The relative importance of different bioclimatic variables and local landscape features, such as forest proportion, forest-urbanization edges, and the presence of specific microhabitats, has been identified as affecting its distribution. Ongoing changes in climate and landscape features are likely to affect the future distribution of this moth species in Nepal. All climate and land cover change scenarios suggest that the suitable habitat for the moth will more than double its current range. © 2025 The Author(s). Ecology and Evolution published by British Ecological Society and John Wiley & Sons Ltd.