When we have a look at the literature, we can find many articles which talk about the yellow mealworm, Tenebrio molitor. Most of the papers focus on the research regarding mealworms as the feed for chickens and other poultry species and only some papers write about the optimal density for breeding of the mealworms and CO2 production. Luckily, there are still many scientists who are interested in working on the feeding of mealworms. Not only do larvae need to be fed, but also adult beetles.
In terms of Science, We found out that there are many different ways of feeding mealworms. For example, one article states that we can just feed the mealworms with wheat bran. Interestingly, the scientists also point out the nutrient contents of the wheat bran. The energy per 100g of wheat bran is about 292 kcal; the protein content is 16,2g; fat content is around 5,3g; carbohydrates content is around 24.9g. While the rests are fibres content and a little bit of salt (see table 2). Another study compares the nutrient contents of different feeds. They found out that we can make an alternative food for mealworms by mixing 50% wheat bran with 50% brewer's spent grain or mixing 50% distillers dried grain in mass production. This mass production can provide food source for larvae with higher quality as well as in lower costs.
In another experiment, the scientist suggests another food source for mealworms. It contains one-third of wheat bran; corn and also corn stalks respectively. It shows that this method has the best utilization rate and also at low costs. In another article, scientists state that they also use oats as feed (see also table 1).
Water is also one of the important sources for mealworm rearing. Most scientists used vegetables for drinking source. For instance, they used cucumbers. Other than cucumbers, an interesting book suggests that salad, paprika, potatoes, apples and carrots are also good water sources. In some YouTube tutorial videos, we found out that mealworms also like celery but it seems that they are not so into eggplants.
What mealworms also like as a drinking source includes radish; cooked potatoes; cabbage; bell pepper stems; ginger peelings; pumpkin and salad. As a substrate for your mealworms, you can also use rolled oats; wheat or oat bran; whole wheat flour; whole breadcrumbs; maize flour and corn meal. Real superfoods are brewer yeast; spent grain; bran and coffee grounds (but not more than 10 %). What you should not feed your mealworms are eggs; garlic; onions; meat or fish offal; dairy; post-cooking scraps with oils and spices; wood; wooden stems or leaves; highly treated or non-peeled fruits and of course not the rotten fruits and vegetables.
Anna Adámková, Martin Adámek, Jiří Mlček, Marie Borkovcová, Martina Bednářová, Lenka Kouřimská, Josef Skácel, Eva Vítová (2017): WELFARE OF THE MEALWORM (TENEBRIO MOLITOR) BREEDING WITH REGARD TO NUTRITION VALUE AND FOOD SAFETY. Potravinarstvo Slovak Journal of Food Sciences vol. 11, 2017, no. 1, p. 460-465.
Sun Young KIM, Hong Geun KIM, Hyung Joo YOON, Kyeong Yong LEE and Nam Jung KIM (2017): Nutritional analysis of alternative feed ingredients and their effects on the larval growth of Tenebrio molitor (Coleoptera: Tenebrionidae). Entomological Research 47 (2017) 194–202.
NUR HASYIMAH, R. – NOR ATIKAH, A. R. – HALIM, M. – MUHAIMIN, A. M. D. – NIZAM, M. S. – HANAFIAH, M. M. – YAAKOP, S. (2018): CO2 EFFECTS ON LARVAL DEVELOPMENT AND GENETICS OF MEALWORM BEETLE, TENEBRIO MOLITOR L. (COLEOPTERA: TENEBRIONIDAE) IN TWO DIFFERENT CO2 SYSTEMS. APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 16(2):1749-1766.
XU Shi-cai, XI Zeng-jun, SHEN Xue-jian, Al Jia-le (2013): Feed Production for Tenebrio molitor L. by Fermentation of Corn Stalks. Animal Husbandry and Feed Science, 5 (5-6), 244-248.
JUAN A. MORALES-RAMOS AND M. GUADALUPE ROJAS (2015): Effect of Larval Density on Food Utilization Efficiency of Tenebrio molitor (Coleoptera: Tenebrionidae). JOURNAL OF ECONOMIC ENTOMOLOGY Vol. 108, no. 5, 2259-2267.
JUAN A. MORALES-RAMOS AND M. G. ROJAS (2015): Effect of Larval Density on Food Utilization Efficiency of Tenebrio molitor (Coleoptera: Tenebrionidae). JOURNAL OF ECONOMIC ENTOMOLOGY Vol. 108, no. 5, 2259-2267.
Köckeritz, M. (2015): Mehlwürmer züchten und nutzen. BoD, Books on Demand, Norderstedt.