Nutrient-specific food selection buffers the effect of nutritional imbalance in the mealworm beetle, Tenebrio molitor (Coleoptera: Tenebrionidae)

Abstract

Abstract. Ingesting nutritionally imbalanced food can cause a significant reduction in fitness in insects. Insects can avoid the negative consequences of nutritional imbalances by selectively foraging for nutritionally complementary foods. We investigated the ability of the omnivorous beetle, Tenebrio molitor (Coleoptera: Tenebrionidae), to redress nutritional imbalances by selecting complementary foods. Beetles were fed one of three synthetic diets that varied in their protein: carbohydrate balance (p0:c42, p21:c21 or p42:c0) for 16 days and then allowed to select between two nutritionally imbalanced but complementary diets (p0:c42 vs. p42:c0) for 18 days. During the initial period, beetle survival was high on all three experimental diets, but their body composition was considerably skewed as a result of eating nutritionally imbalanced diets. Over the first 6 days of food choice (days 16-22), beetles previously fed a protein-rich, carbohydrate-deficient diet (p42:c0) preferred carbohydrate to protein, whereas those previously fed a carbohydrate-rich, protein-deficient diet (p0:c42) strongly preferred the protein-rich diet. When the food choice period continued for longer than 6 days, the selection of diets by previously carbohydrate-deprived beetles (p42:c0) was similar to that of the control beetles previously fed an optimal food (p21:c21). However, beetles that were previously fed on the protein-deficient diet (p0:c42) selected protein and carbohydrate equally throughout the remaining period of food choice and the cumulative protein-carbohydrate intake of these protein-deprived beetles was similar to that of those fed the optimal diet (p21:c21). At the end of the experiment, the body composition of all beetles was similar, indicating that the effects of nutritional imbalance on body composition were buffered by the subsequent selection of complementary foods. Our results demonstrate that T. molitor beetles are capable of redressing nutritional imbalances and indicate that the way in which the nutritional balance of beetles is restored depends on the nutrient that is initially deficient in their food.

Self-Selection of Feeding Substrates by Tenebrio molitor Larvae of Different Ages to Determine Optimal Macronutrient Intake and the Influence on Larval Growth and Protein Content

“…The results presented in this study are consistent with previous studies and show that Tenebrio molitor larvae tend to regulate their uptake of nutrients by choosing from a variety of substrates during feeding and have a self-selection ability to ensure an optimal macronutrient ratio [ 18 , 19 , 20 , 26 , 27 ]. The intake of macronutrients varied greatly according to the specific feed.…”

Self-Selection of Agricultural By-Products and Food Ingredients by Tenebrio molitor (Coleoptera: Tenebrionidae) and Impact on Food Utilization and Nutrient Intake

“…It is apparent by the results presented in this study that T. molitor larvae tend to balance their intake of macro nutrients by selecting among a variety of ingredients when feeding. This agrees with previous studies confirming the ability of T. molitor to self-select for optimal macro-nutrient intake ratios [41][42][43][44]. The intake ratios of macro nutrients by T. molitor larvae converged within a narrow range of values among eight of the nine combination treatments of different food ingredients.…”

Perilaku pemilihan pakan plastik dan respons biologi imago kumbang Tenebrio molitor L. (Coleoptera: Tenebrionidae)

“…Hasil penelitian menunjukkan bahwa kumbang lebih tertarik pada pakan pollard yang mengandung cukup keseimbangan nutrisi untuk kebutuhan hidupnya. Rho & Lee (2015) menyatakan bahwa larva kumbang T. molitor mampu melakukan kompensasi pemulihan kekurangan satu nutrisi dengan memilih makanan yang mengandung kelebihan nutrisi lainnya. Kumbang T. molitor dilaporkan sangat bergantung pada diet asupan karbohidrat, sesuai dipelihara pada pakan berbasis biji-bijian, seperti dedak, tepung, ataupun serpihan gandum (Kröncke & Benning 2022).…”