Prediction of Occurrence Timing of Stenotus rubrovittatus（Matsumura）（Heteroptera: Miridae）into Rice Paddy Fields Based on Rice Heading Stage Forecasting

Stenotus rubrovittatus（Matsumura）（Heteroptera: Miridae）is a serious pest that causes pecky rice grains by sucking out the contents of developing rice kernels. Because the adult S. rubrovittatus migrates to rice paddy fields during the heading stage, the occurrence of this pest in the paddy fields is likely to depend on the heading date of the rice. This study investigated the heading dates of rice and the peak occurrence dates of S. rubrovittatus adults in several rice paddy fields in Ibaraki Prefecture from 2021 to 2024. The occurrence peak of the adults in each paddy field was then predicted by using a developmental-rate-type（DVR-type）phenological model of rice. The DVR-type model predicted the occurrence peak of S. rubrovittatus adults more accurately than the traditional effective accumulated temperature model for insects, with a root mean square error of 1.59 days, a mean absolute error of 0.84 days, and an R2 value of 0.77. These results demonstrate the effectiveness of the DVR-type phenological model in predicting the occurrence peaks of S. rubrovittatus in rice paddy fields.