Atmospheric cold plasma-induced mortality in Sitophilus oryzae (L.)

Abstract

The rice weevil, Sitophilus oryzae, is a common pest in grain storage and agriculture, causing considerable damage to stored grains. Increasing resistance of rice weevils to current fumigation methods continues to occur, necessitating the development of alternative control strategies. In this study, we investigated the impact of atmospheric cold plasma (ACP) on the mortality of rice weevils. ACP generates non-thermal ionized gas at or near room temperature and has been effective in inactivating microorganisms and pests, including rice weevils. We hypothesized that ACP treatment would have detrimental effects on the weevils, leading to a high mortality rate. To evaluate this hypothesis, we applied a treatment voltage of 80 kV and treatment times of 0, 3, 5, 8, and 10 min across all life stages of rice weevils, including the egg, larval (1st – 4th instars), pupal, and adult phases. Additionally, we examined post-treatment retention times of 0, 24, 48, and 72 h to assess how long the treated weevils survived after exposure. We observed that both treatment time and post-treatment retention time impacted, especially for weevils treated with shorter durations. Higher treatment times (5,8, and 10 min) showed that eggs failed to hatch, larvae and pupae were unable to emerge, and adults either died immediately after treatment (depending on the treatment duration) or within 24–48 h post-treatment. Based on these findings, we can conclude that ACP has detrimental effects on rice weevils, providing valuable insights into the potential use of ACP as an integrated pest management strategy.