Climate Change Drives the Distribution of Insect Vectors for GLRaV-3 on a Global Scale.

Grapevine leafroll-associated virus 3 (GLRaV-3) is a significant plant virus affecting grapevines worldwide, causing considerable economic losses. Soft scale insects (Coccidae) serve as key vectors for GLRaV-3 transmission. Understanding how climate change impacts the distribution of these vector species is crucial for improving grapevine disease management strategies. Despite previous studies focusing on other insect vectors, limited research has been conducted on soft scale species, especially in the context of climate change. This study addresses the research gap by predicting the future global distribution of soft scale species responsible for GLRaV-3 transmission under various climate change scenarios. The potential distribution of seven soft scale species was analyzed using the MaxEnt model. Data on species occurrence were gathered from global biodiversity databases, and key environmental variables were identified using principal component analysis. Climate projections were incorporated using Shared Socioeconomic Pathways (SSPs) under four future timeframes (2030s, 2050s, 2070s, 2090s). The model indicated that temperature plays a critical role in limiting soft scale distribution, with projections showing a northward shift in distribution for several species under climate change. Three species are expected to expand their range, while the remaining four may see a reduction in suitable habitat. These shifts suggest potential changes in GLRaV-3 transmission risk in key grapevine-growing regions. This research provides vital insights into the future distribution of GLRaV-3 vectors, helping to guide targeted surveillance and management strategies. By predicting potential outbreak areas, this study contributes to the proactive management of grapevine diseases under changing climatic conditions.