Demographic suppression and oxidative responses of Tribolium beetles to cold‐plasma and microwave treatment in wheat flour: efficacy‐quality trade‐offs

Abstract

BACKGROUND Non‐chemical physical treatments may complement stored‐product pest management, but acute mortality alone may underestimate their value when surviving adults reproduce poorly and post‐treatment population recovery is suppressed. This study compared atmospheric cold‐plasma (CP; 10–20 kV) and microwave (MW; 300–900 W) exposure against sex‐balanced adult cohorts of Tribolium castaneum and Tribolium confusum in wheat flour. RESULTS Mortality increased with intensity and exposure duration. At 20 min, Abbott‐corrected mortality reached 59.07% and 53.65% under CP‐20 kV and 59.59% and 59.38% under MW‐900 W in T. castaneum and T. confusum , respectively. Despite incomplete acute mortality, F 1 emergence declined from 199.4 and 163.8 adults in untreated controls to 15.0 and 20.4 after CP and to 5.0 and 1.4 after MW. Both technologies delayed adult pre‐oviposition, shortened oviposition and longevity, reduced flour loss, and increased superoxide dismutase (SOD), catalase (CAT), glutathione S ‐transferase (GST) and malondialdehyde (MDA) in survivors. In independent flour‐only assays at 20 min, MW‐900 W caused the largest quality changes, increasing peroxide value and free fatty acids while reducing extractable oil and gelatinization enthalpy. Species‐specific exploratory principal component analysis (PCA) and canonical discriminant analysis (CDA) of control and 20‐min profiles identified dominant treatment gradients. Principal component one (PC1) explained 90.55% and 89.84% of variance, and mean repeated five‐fold cross‐validation accuracy was 85.5% and 85.9%. CONCLUSION CP and MW substantially suppressed post‐treatment population recovery beyond 24‐h mortality. MW gave stronger combined suppression but larger flour‐quality changes, whereas CP caused smaller measured quality shifts under the tested laboratory conditions. © 2026 Society of Chemical Industry.