Wireworm feeding on potatoes during ripening is affected by soil moisture, tuber mass, and cultivar but not by tuber CO2 respiration

Abstract Wireworms, the larval stage of click beetles (Coleoptera: Elateridae), cause substantial damage to potato tubers, particularly during the ripening phase. Management strategies such as early harvest and the use of less susceptible cultivars have been shown to reduce feeding damage. However, the mechanisms driving cultivar susceptibility and the key factors influencing wireworm feeding during ripening remain poorly understood. To address this gap in knowledge, we compared the effects of harvest date, soil moisture, tuber mass, and wireworm abundance on feeding damage of wireworms (Agriotes spp.) during ripening in 2 potato cultivars. Additionally, we investigated whether differences in potato tuber CO2 respiration are responsible for cultivar susceptibility to wireworm damage. Feeding damage significantly varied between cultivars and harvest dates. Early harvest reduced damage in the highly susceptible cultivar but had no effect on the less susceptible cultivar. Soil moisture primarily affected wireworm abundance in the ridge, which decreased under low soil moisture conditions. In the susceptible cultivar, feeding marks increased significantly under low compared to high soil moisture. Tuber mass was positively related to damage, with heavier tubers showing more damage. Differences in tuber CO2 respiration between cultivars neither influenced wireworm feeding nor explained differences in susceptibility. These findings highlight the potential of selecting suitable cultivars and managing soil moisture, harvest timing, and tuber mass to reduce wireworm damage during potato tuber ripening. Understanding the mechanisms of cultivar resistance and breeding more resistant varieties will help minimize wireworm-related crop losses in potatoes.