Black soldier fly larvae are generally rich in nutrients. They are particularly high in protein and fat. This makes them an excellent agent for biological conversion of organic wastes. However, in direct accordance with the saying that you are what you eat, there is considerable variation in larval body composition depending on the contents and quantity of their rearing substrates. Furthermore, body composition changes as larvae grow. Crude protein content usually decreases with increasing larval age. The opposite is true for fat content.

Based on the published results of proximate analyses, average dry matter content of recently harvested larvae ranges between 20 and 44%. Within this dry matter, protein amounts to 37-63% of dry matter, while fat amounts to 7-39% of dry matter. Larvae may also serve as a source of calcium (1-6% of dry matter), as well as phosphorus, potassium, and magnesium.

Black soldier fly larvae commercially available as a feed ingredient are likely to be sold as dehydrated and partially defatted meal. provides an approximate composition for black soldier fly meal that is less than 20% in fat and more than 20% in fat. However, as described above, it is important to remember that exact composition depends on the source of black soldier flies. Therefore, it is prudent to test it before formulating feeds.