Predicting the global potential distribution of Bursaphelenchus xylophilus using an ecological niche model: expansion trend and the main driving factors

Bursaphelenchus xylophilus is a pest that interferes with the health of forests and hinders the development of the forestry industry, and its spread is influenced by changes in abiotic factors and human activities. The potential distribution areas of B. xylophilus in China under four shared-economic pathways were predicted using the optimized MaxEnt model (version 3.4.3), combining data from a variety of environmental variables: (1) prediction of natural environmental variables predicted under current climate models; (2) prediction of natural environmental variables + human activities under current climate models; and (3) prediction of natural environmental variables under the future climate models (2050s and 2070s). Meanwhile, whether the niche of B. xylophilus has changed over time is analyzed. The results showed that human activities, precipitation in the driest month, annual precipitation, and elevation had significant effects on the distribution of B. xylophilus. In the current conditions, human activities greatly reduced the survival area of B. xylophilus, and its suitable distribution area was mainly concentrated in the southwestern and central regions of China. Under the influence of climate change in the future, the habitat of B. xylophilus will gradually spread to the northeast. In addition, the ecological niche overlap analysis showed that B. xylophilus in future climate was greater than 0.74. This study provides important information for understanding the ecological adaptation and potential risk of B. xylophilus, which can help guide the decision making of pest control and forest protection.

Evaluating the Impact of Climate Change and Human Activities on the Potential Distribution of Pine Wood Nematode (Bursaphelenchus xylophilus) in China

Zhang,

Wang,

Xie

et al. 2024

Tetramycin B3: An Effective and Biological Nematicide for Bursaphelenchus xylophilus

Sun,

Li,

et al. 2024

Pine wilt disease, caused by Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) Nickle 1981, poses a significant threat to the safety of pine forests in the world. Currently, the available nematicides for controlling this disease are limited. Finding new nematicides is crucial for the effective prevention and control of pine wilt disease. In this study, we discovered that tetramycin B3, derived from Streptomyces ahygroscopicus, demonstrated a promising effect on pine wilt disease. The LC50 values of tetramycin B3 at 24, 48, and 72 h were 26.49, 23.37, and 12.79 μg/mL, respectively. Tetramycin B3 significantly inhibited the feeding and growth rate of B. xylophilus at low concentrations while also increasing ROS (reactive oxygen species) production and lipid accumulation. Furthermore, tetramycin B3 markedly inhibited the activity of detoxifying and protective enzymes. Transcriptome and metabolome analyses indicated that tetramycin B3 significantly affected the expression of genes related to lysosomes, autophagy, and lipid metabolism in B. xylophilus. Additionally, tetramycin B3 delayed the onset of pine wilt disease. Transcriptome results showed that tetramycin B3 significantly influenced the expression of genes related to defense responses in pine trees and induced pine trees to produce disease-resistant mechanisms. Future research will focus on further elucidating the mechanism of action of tetramycin B3 against B. xylophilus and verifying the gene functions identified through transcriptome screening.

A Digital Management System for Monitoring Epidemics and the Management of Pine Wilt Disease in East China

Zhang,

Chen,

et al. 2024

The precise monitoring of forest pest and disease outbreaks is a crucial prerequisite for efficient prevention and control. With the extensive application of remote sensing monitoring technology in the forest, a large amount of data on pest and disease outbreaks has been collected. It is highly necessary to practically apply these data and improve the efficiency of forest pest and disease monitoring and management. In this study, a Digital Forest Protection (DFP) system based on the geographic information system (GIS) was designed and developed for pine wilt disease (PWD) monitoring and management, a devastating forest disease caused by the pine wood nematode, Bursaphelenchus xylophilus. The DFP system consists of a mobile app for data collection and a web-based data analysis platform. Meanwhile, artificial intelligence and deep-learning methods had been conducted to integrate a real-time unmanned aerial vehicle (UAV) remote sensing monitoring with PWD detection. This system was implemented in PWD monitoring and management in Zhejiang Province, China, and has been applied in data collection under certain circumstances, including the manual epidemic survey, the UAV epidemic survey, and eradication monitoring, as well as trunk injection. Based on DFP system, the effective monitoring of PWD outbreaks could be achieved, and corresponding efficient management strategies could be formulated in a timely manner. This allows for the possibility to optimize the integrated management strategy of PWD on a large geographic scale.