# Predicting current and future areas of ecological suitability for Lutzomyia longipalpis sensu lato in the Americas

## TL;DR

This study predicts where the sand fly Lutzomyia longipalpis may live now and in the future in the Americas, based on climate and environmental factors.

## Contribution

The study identifies key climate and environmental drivers and models future range expansion of Lu. longipalpis under climate change scenarios.

## Key findings

- Current ecological suitability spans from the southern U.S. to northern Argentina.
- Future projections suggest northward expansion and increased suitability in Mexico and Brazil.
- Key drivers include temperature, growing degree days, and climate classification.

## Abstract

Leishmania infantum is one of the etiologic agents of leishmaniases in mammals. In the Americas, numerous sand fly species within the Lutzomyia genus drive Leishmania spp. transmission, such as the species complex Lutzomyia longipalpis sensu lato. It remains unknown if climatic changes could facilitate range expansion of Lu. longipalpis, creating conditions for local transmission in previously non-endemic regions. The objectives of this study were to identify the climatic and environmental variables of importance for Lu. longipalpis, current ecologically suitable area across the Americas, and determine future areas of ecological suitability under 30-year time periods. Occurrence records were obtained from GBIF, WRBU, and literature searches. Historic climate data (1981–2010) and projection data for Shared Socioeconomic Pathway 3-7.0 for time periods 2041–2070, and 2071–2100 were obtained from CHELSA, along with topographic data from EarthEnv. Using MaxEnt species distribution modelling algorithms, data were incorporated to identify areas which currently are or may become suitable for Lu. longipalpis. Ecological variables such as terrain ruggedness index, number of growing degree days at which mean daily air temperature is above >10 °C, Köppen–Geiger climate classification, and mean daily air temperature of the coldest quarter, were identified as drivers of suitability. Current regions of ecological suitability include areas from the southern United States to northern Argentina. Suitability may expand northward and increase within its current range, specifically in parts of Mexico and Brazil. Findings from this study identify climate and environmental variables impacting Lu. longipalpis distribution, and regions of potential range expansion.