# Projecting Current and Future Habitat Suitability of the Pepper Weevil, Anthonomus eugenii Cano, 1894 (Coleoptera: Curculionidae), in China: Implications for the Pepper Industry

## TL;DR

This study predicts how climate change will affect the habitat of the pepper weevil in China, helping to protect pepper crops.

## Contribution

The study projects future habitat suitability of the pepper weevil under climate change using MaxEnt modeling in China.

## Key findings

- Currently, 28.47% of China's area is suitable for the pepper weevil.
- Future climate scenarios show reduced suitable habitats, except in some cases, with shifts toward the southwest.
- Annual mean temperature and precipitation of the coldest quarter are key factors influencing the pest's distribution.

## Abstract

The pepper weevil, Anthonomus eugenii Cano, stands out as a particularly destructive pest, causing substantial losses in Capsicum pepper production. Therefore, accurately identifying its distribution is crucial for effective monitoring and prevention strategies under climate warming scenarios. Using MaxEnt modeling and ArcGIS, this study mapped current and future suitable habitats for the pepper weevil in China under four climate scenarios from 2030 to 2090. The findings indicated that while the pest currently occupies 28.47% of China’s area, future climate changes could lead to reduced suitable habitats, except in certain scenarios, with shifts towards southwestern regions expected. Our findings offer crucial insights for early monitoring and managing of A. eugenii populations, as well as for choosing suitable sites for pepper cultivation that are free from pest infestations.

The pepper weevil, Anthonomus eugenii Cano, 1894 (Coleoptera: Curculionidae), poses a significant threat to pepper cultivation, causing extensive crop damage and economic losses. While numerous studies have addressed its occurrence, biology, and control methods, less attention has been given to how climate change might alter its distribution. This research utilized the optimized MaxEnt model to project the current and future habitat suitability of the pepper weevil under four distinct climate scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) for the periods spanning the 2030s to 2090s. Optimal model performance was achieved with a regularization multiplier of two and a feature combination of QHP, yielding high predictive accuracy with mean testing AUC values of 0.921. The analysis identified annual mean temperature (Bio1) and precipitation of the coldest quarter (Bio19) as the primary environmental factors influencing the pest’s distribution. Currently, in China, suitable habitats for A. eugenii encompass an area of 273.74 × 104 km2 or 28.47% of the nation’s territory, predominantly located in central, eastern, southern, and southwestern regions. Future projections suggest that suitable areas are expected to shrink across various scenarios, barring increases in specific instances like SSP126-2050s, SSP245-2070s, and SSP370-2050s, with shifts towards southwestern regions. This investigation deepens our comprehension of agricultural pest dynamics under climate change and supports the formulation of preemptive management strategies to safeguard agricultural productivity.