【目的】 明确沈阳地区玉米田双斑长跗萤叶甲Monolepta hieroglyphica成虫的种群消长动态，为该虫的监测、预测和防控技术研发提供依据。【方法】 2020-2021年在辽宁省沈阳市沈北新区设置系统观测田，自玉米出苗至收获前（5月中旬-9月下旬）进行定期调查。种群动态和空间分布调查：双斑长跗萤叶甲成虫在玉米田始见后，采用五点取样法，在玉米田中调查成虫发生数量和在植株不同部位的分布；雌雄虫性比调查：定期在玉米非系统观测田边和周边杂草上采集固定数量成虫，分辨成虫性别。【结果】 2020和2021年沈阳地区双斑长跗萤叶甲成虫在玉米田始见期（玉米为大喇叭口期）分别是6月30日和7月9日；发生高峰期（玉米快速灌浆期）分别是7月30日和8月4日，高峰期虫量分别为（741.25±47.63）和（337.5±67.69）头/百株；9月末在玉米田消失。在玉米的不同生长阶段，成虫在玉米植株上的空间分布不尽相同：2020年7月上旬，下部叶片的虫量占47%以上，7月中下旬至8月上旬，上部叶片占40%-70%，8月中旬，雌穗部位占54.05%；2021年7月中旬，中部叶片占59.52%以上，7月下旬，上部叶片占40%-60%，8月初，雌穗部位占53.46%。2020年雌雄性比动态为1∶4.88-1∶0；2021年为1∶4.56-1∶0.25。【结论】 双斑长跗萤叶甲成虫在沈阳地区玉米田始见期为6月下旬至7月上旬，高峰期为7月下旬至8月上旬，9月中下旬数量骤降至消失。在玉米的不同生长阶段，成虫在玉米植株上的空间分布相对稳定，抽雄前主要分布于中下部叶片，吐丝至灌浆期主要分布于雌穗上，蜡熟期少量成虫分布于中上部叶片。玉米大喇叭口期至快速灌浆期，雄虫占比较高，种群高峰期过后，雌虫占比逐渐增加直至占据绝大部分。

[Aim]  This study aims to gain an understanding of the population dynamics of adult Monolepta hieroglyphica in maize fields in the Shenyang area. The findings will establish a foundation for pest monitoring and the development of effective control strategies. [Methods]  During 2020 and 2021, maize fields located in the Shenbei District of Shenyang City were monitored periodically from germination until the harvest stage (mid-May to late-September). Population dynamics and spatial distribution were investigated as follows: M. hieroglyphica were counted using a five-point sampling method to determine the number and distribution on different parts of the plants after adults being found in the maize fields, and the adult sex ratio was investigated. A fixed number of adults were collected from the weeds surrounding the maize fields, the sex of the adults was determined. [Results]  In 2020 and 2021, adult Monolepta hieroglyphica were first observed in the Shenyang corn (vegetative 12 stage) fields on June 30th and July 9th, respectively. Peak insect densities were recorded on July 30th and August 4th (rapid filling stage), with (741.25±47.63) and (337.5±67.69) individuals per hundred plants, respectively. By the end of September, no individuals were seen in the corn fields while a small number of adults remained in the weeds at the field edge. There was temporal variation in the spatial distribution of adults on corn plants at different growth stages of maize. at different growth stages of maize. In early July 2020, over 47% adult M. hieroglyphica were found on the lower leaves. In contrast, 40%-70% of adults were found in the upper leaves during late July to early August, with a spike in females accounting for 54.05% of the distribution. In mid-July 2021, 59.52% of adults were found on the middle leaves, and in late July, 40%-60% of adults were distributed in the upper leaves. A spike in females in early August accounted for 53.46% of the adult distribution. The male-to-female ratio (♀/♂) was 1︰4.88-1︰0 in 2020 and 1∶4.56-1∶0.25 in 2021. [Conclusion]  In 2020 and 2021, adult M. hieroglyphica first appeared in the Shenyang corn fields in late June to early July. The population peaked in late July to early August, then sharply declined with no individuals remaining by mid to late September. The spatial distribution of adults on corn plants was relatively stable at different growth stages of maizes. The population was primarily distributed in the lower leaves before the tasseling stage, with spikes in the female population during the silking to the milk stage. As the dough stage, the adults tended to be distributed in the middle to upper leaves. Male insects dominated higher proportion vegetative 12 stage to rapid filling stage. However, after the population peaked, the proportion of females gradually increased until they were the majority.