Cascading biological consequences of acute heat shock in Trogoderma granarium (Coleoptera: Dermestidae) and Oryzaephilus surinamensis (Coleoptera: Silvanidae).

Acute heat exposure can suppress stored-product insects through delayed survivor-level impairment that is not captured by mortality alone. This study evaluated the biological consequences of high temperature shocks to Trogoderma granarium Everts (Coleoptera: Dermestidae) and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). Adults, larvae, eggs, and developmental cohorts were exposed to factorial combinations of 40, 42, 44, 46, and 48 °C and 5, 15, 30, and 45 min, with untreated controls maintained under standard rearing conditions (27 ± 1 °C, 65 ± 5% RH, and a 12:12 h light:dark photoperiod). Endpoints included delayed mortality, post-shock dormancy recovery, feeding indices, egg hatchability, pupation, adult emergence, F1 adult emergence, eggs per female, and approximate cohort-level population descriptors. Heat exposure produced a coordinated severity-dependent response. Increasing temperature and exposure duration increased delayed mortality and prolonged dormancy recovery, while reducing relative growth and consumption rates and increasing feeding deterrence. Developmental performance was impaired through lower hatchability, reduced pupation and adult emergence, and longer development. Reproductive and progeny-related endpoints declined consistently, with reduced F1 emergence and lower total F1 adult production. These descriptors represent comparative cohort-level indicators and should not be interpreted as full age-stage, two-sex life-table estimates. Multivariate analyses separated performance-associated traits from injury-associated traits and confirmed that heat severity shifted both species from viable biological performance toward delayed recovery, feeding -suppression, developmental impairment, and reduced progeny recruitment. These findings indicate that acute heat-shock injury in stored-product beetles should be evaluated using integrated lethal, functional, developmental, reproductive, and population-level endpoints rather than mortality alone.