Temperature-dependent development models for Hydrochara affinis were built to estimate the ecological parameters as fundamental research for monitoring the impact of climate change on rice paddy ecosystems in South Korea. The models predicted the number of lifecycles of H. affinis using the daily mean temperature data collected from four regions (Cheorwon, Dangjin, Buan, Haenam) in different latitudes. The developmental rate of each life stage linearly increased as the temperature rose from 18°C to 30°C. The goodness-of-fit did not significantly differ between the models of each life stage. Unlike the optimal temperature, the estimated thermal limits of development were considerably different among the models. The number of generations of H. affinis was predicted to be 3.6 in a high-latitude region (Cheorwon), while the models predicted this species to have 4.3 generations in other regions. The results of this study can be useful to provide essential information for estimating climate change effects on lifecycle variations of H. affinis and studies on biodiversity conservation in rice fields.

The study conducted to understand the annual phenology of hemipteran insect pests including Halyomorpha halys, Nezara antennata, Plautia stali, and Riptortus pedestris in Jeju, Korea, 2017 and 2018. We investigated the population density of them at three locations for two years. The commercial and fish trap were used for monitoring. We compare the seasonal occurrence among species and sampling locations. The repeated measured ANOVA was used to explain the difference of seasonal occurrence among locations and sampling time. There was difference the first adult catch and the peak occurrence of species among sampling sites.