Trogoderma granarium Everts (Coleoptera: Dermestidae) is recognized as one of the most damaging quarantine insects on stored grains. However, with the increasing international trade of gluten-free products, it is important to increase our current level of knowledge to better understand their potential susceptibility to infestation by this quarantine insects. For this, the study examined the development potential of T. granarium on three internationally traded gluten-free products, quinoa, chia, and linseed, when subjected to whole and flour forms of these products. The adults of T. granarium were allowed to grow on whole and flour forms of each product, and the progeny development were recorded after 65 days. Results on population growth, frass production and commodity weight loss, differed significantly on different products as well as their forms. Progeny development, egg production, and pupal weight of T. granarium as well as frass production and commodity weight loss, were found to be significantly higher in quinoa, especially in flour, compared to other products. Chia seeds, both in whole and flour form, recorded the lowest results on above parameters. Linseed was found to be support highest insect pupal weight as well as frass production. These results demonstrate that both the commodity itself and physical form strongly affect T. granarium population dynamics and damage. The findings point out quinoa flour as a high-risk commodity for infestation and highlight the need to incorporate emerging gluten-free commodities into postharvest risk assessment programs.
Yunus Emre Altunç (2026) studied this question.