Are insect meals prone to insect infestation during storage? Development of major storage insects on substrates based on Tenebrio molitor larvae meal

Abstract

Insect meal is a new agricultural commodity that will be produced in huge quantities in the near future and will be treated as all traditional agricultural commodities, i.e., insects will be harvested, processed, transported and stored. As most agricultural commodities, insect meals may be prone to insect infestations during their “post-harvest stages.” However, no information is available at the moment on the susceptibility of insect meals to stored-product insect infestations. The objective of the present study was to evaluate the susceptibility of Tenebrio molitor larvae-meal to insect infestations during storage. Specifically, we investigated the population growth of major stored-product insects, i.e., T. molitor, Tribolium confusum, Alphitobius diaperinus and Trogoderma granarium on T. molitor larvae-meal, as well as on T. molitor meal-based substrates with different percentages of wheat bran (0, 25, 50, 75, 90, 95 and 100%). Our results show that T. molitor and T. confusum can infest 100% T. molitor meal and develop significant populations on this substrate. However, the speed of growth of both species in 100% T. molitor meal was considerably lower compared to the substrates that contained also wheat bran. In contrast, A. diaperinus and T. granarium did not grow at all on 100% T. molitor meal and both exhibited poor growth on the substrate containing 75% insect meal. In general, our results show the susceptibility of T. molitor larvae meal, as well as T. molitor meal-based substrates with different percentages of wheat bran, to infestations by major stored-product insects. To our knowledge, this is the first study on the susceptibility of insect meals to insect infestations. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.