桃小食心虫是我国北方果树生产中为害严重的食心虫之一，具有发生区域广、危害树种多、经济损失重、防控难度高等特点。在果树生产中，桃小食心虫成虫在田间的首次出现时间与数量动态变化趋势一般被作为对其防控的重要参考依据。明确桃小食心虫成虫的田间发生规律，有利于在果树生产中制定精准科学的防治策略，可有效控制田间桃小食心虫的种群数量。为了掌握辽宁苹果产区桃小食心虫发生数量变化规律，文章研究通过在苹果园内悬挂性诱剂诱捕器的方法，定点采集和监测了2019—2021年桃小食心虫每日发生数量，形成本数据集。本数据集可为进一步明确我国桃小食心虫的生物学习性与生态学规律提供科学的参考依据，为开展桃小食心虫绿色高效精准防治提供详实的数据基础。

Carposina sasakii (Lepidoptera: Carposinidae) is one of the most dangerous pest in fruit production in northern China. It has the characteristics of a wide range of occurrence, a variety of fruit tree hosts, serious economic losses, and difficult prevention and control. The first emergence time and population dynamic trend of C.sasakii adults in orchards are generally used as an important reference basis for its control. It is beneficial to construct pest control strategies in fruit tree production, and to effectively control the population of C. sasakii in orchards. In order to master the happening dynamic of C.sasakii in the apple producing areas of Liaoning province, the present dataset was generated by collecting the daily occurrences of adult C.sasakii from 2019 to 2021 at a fixed point by hanging a sex bait trap in the apple garden to form this dataset. This dataset could provide a scientific reference for further clarification of the biology and ecology of C.sasakii, and provide a detailed data basis for green, efficient and precise control of C.sasakii.