Evaluation of various diets for improved growth, reproductive and nutritional value of the yellow mealworm, Tenebrio molitor L.

Breeders are under growing pressure to enhance the production of farmed insects and shorten their life cycles due to the rising demand for edible insects. Feed for yellow mealworm was developed using five feed sources viz., faba bean flour, chickpea flour, wheat bran, wheat germ and Yeast, alone and in combination and resulting in 19 diet treatments. An investigation was carried out to determine the effects of diet combinations on the development, weight, and growth of Tenebrio molitor larvae, pupae, and adults. Results indicate that the larvae fed on diet 18 gained the most length and weight, measuring18.45 mm and 184.62 mg, respectively. The maximum length and weight, measuring 23.30 mm and 146.00 mg on diets 19 and 15 in pupae and 14.45 mm and 119.27 mg on diets 11 and 17 in adults, respectively. The shortest developmental durations were 61.00 and 6.36 days for larvae and pupae on diet 3. The shortest adult longevity was 7.00 days on diet 16. The highest fecundity rate was significance different (43.82 eggs/female) fed on diet 8 compared to the other diets. The highest percentage of adult emergence was 76.71% on diet 9. The shortest total developmental period was 88.01 days in diet 4. The maximum growth index was 2.61 in diets 6. The highest percent of protein, carbohydrate and fat contents of T. molitor were 49.46, 74.83 and 39.91% in larvae fed on diets 5, 10 and 3. The findings showed that wheat germ is an appropriate diet to enhance yellow mealworm production either on its own or in combination with other diets.