Pest Occurrence and Temperature Rising Trend in Major Apple Growing Areas in South Korea

The temperature rising trend over the past 50 years in Yeongju and Uiseong, which are major apple growing regions in Korea, was analyzed, and future temperature change trends were confirmed from climate data predicted according to the SSP 4.5 and 8.5 scenario for 2050s. In addition, the damage rate of pests occurring in apple orchards in Gunwi from 2005 to 2022 was investigated. Regression and correlation analysis were performed on these data to confirm the relationship between major pest occurrence indicators and meteorological factors. With the climate change in the growing region, the temperature in March is significantly increased, suggesting that the flowering of apple tree may be brought forward in the future and that the growing region may also change to northward. The relationship between the 1st peak occurrence date or the total annual occurrence amount of the investigated pest species, and the average temperature data in Gumwi was analyzed to confirm that the occurrence pests is closely related to temperature changes. The 1st peak occurrence date of the Grapholita molesta was advanced as the average temperature in winter and March increased, and the annual total occurrence amount of the Carposina sasakii and the Halyomorpha halys grew as the average temperature in spring increased. In the case of C. sasakii, the end date of six consecutive days with a minimum temperature of 3℃ or higher shows a high correlation with the first peak occurrence date, which seems to be helpful not only for the relationship between temperature fluctuations and insects, but also for the early prediction. Accordingly, it was confirmed that the occurrence of pests in apple orchards will vary with temperature changes under future climate conditions. Therefore, the necessity for establish a future control strategy using existing observation data according to climate change was concerned.