Parental acclimation reduces offspring thermal fitness in the postharvest insect species Sitotroga cerealella (Olivier)

Abstract: Transgenerational plasticity (TGP) is a physiological mechanism that allows
parental environmental experiences to shape their offspring phenotypes and may aid
survival under stressful environments. However, the thermal TGP responses of many
insects, including Sitotroga cerealella, a significant primary grain pest, is poorly
understood. Specifically, it is unknown how sub-lethal stress in one generation influences
fitness or lack thereof in next generations. Here, we assessed how heat (acute, chronic, and
dynamic) and cold acclimation in F1 affects F2 fitness through TGP responses using
laboratory-reared S. cerealella as a model. Our results showed that F1 heat acclimations
had a significant effect on F1 CTmax. Both heat and cold acclimation reduced F2 CTmax
compared to the controls, suggesting a TGP fitness cost. These costs of TGP may have
implications on the development of phytosanitary grain treatments.