Occurrence characteristics and causes of meadow moth Loxostege sticticalis outbreaks in China in 2021

Author of the article:ZHANG Yi-Yang, LIU Jie, ZHAO Su-Mei, YIN Xiang-Jie, ZHANG Yun-Hui, BIAN Yue, ZENG Juan, JIANG Yu-Yin

Author's Workplace：National Agro-technical Extension and Service Centre, Beijing 100125, China

Key Words：meadow moth; monitoring; moth peaks

Abstract：[Objectives]  The meadow moth Loxostege sticticalis is an important migratory pest in northern China, which poses a serious threat to the production safety in the agricultural and pastoral intercropping areas in north, northeast and northwest China. Clarifying the characteristics and causes of the annual occurrence of the L.sticticalis can provide an important theoretical basis for early monitoring, prevention and control in the future. [Methods]  In north, northwest and northeast China, first appearance date, occurrence peak, moth data and occurrence number of the adults were monitored by pest monitoring lamps and high altitude lamps. Adult and larval field population densities were investigated by artificial field survey, and the occurrence area was estimated to analyze the temporal and spatial dynamics of the L.sticticalis. [Results]  The meadow moth, L. sticticalis, occurred in many parts of China in 2021. Most of Inner Mongolia, northern Hebei and Shanxi had frequent peaks of meadow moth abundance and most of Inner Mongolia and Zhangjiakou in Hebei had high numbers of overwintering adults. First generation of larvae were mostly observed in Inner Mongolia and northern Shanxi. [Conclution]  A high number of overwintering adults was the main reason for the moderate meadow moth abundance in Inner Mongolia and surrounding areas in 2021. The high spring temperature that year resulted in an earlier overwintering adult generation in most areas. Furthermore, suitable precipitation and temperature in central and western Inner Mongolia and surrounding areas were key factors leading to outbreaks of L. sticticalis larvae. Favorable wind conditions are also an important factor affecting the number of population peaks and the distribution of this pest in space and time. L. sticticalis populations in Inner Mongolia and surrounding areas are sources of immigrant moths for local migrations within this region.