Page 625 - Hand rearing birds second

626 Hand-Rearing Birds

Table­41.1­ Moisture, protein, fat, fiber, and ash content of selected invertebrates.

Moisture Crude Crude Acid­Detergent­ Ash­ Energy­
Species – Life­stage (%) Protein (%) a Fat­(%) Fiber­(%) (%) (kcal/g)

Waxworms (Galleria 58.5 14.1 24.9 3.4 0.6 2.75
mellonella) – larvae
Mealworms (Tenebrio molitor) – larvae 61.9 18.7 13.4 2.5 0.9 2.05
Superworms (Zophbas morio) – larvae 57.9 19.7 17.7 2.7 1.0 2.42
Silkworms (Bombyx mori) – larvae 82.7 9.3 1.4 1.1 1.1 0.67
Butterworms (Chilecomadia 60.2 15.5 29.4 1.4 0.8 2.98
moorei) – larvae
Soldier flies (Hermetia 61.2 17.5 14.0 3.0 3.5 1.99
illucens) – larvae
Crickets (Acheta domesticus) – adults 69.2 20.5 6.8 3.2 1.1 1.40
Crickets (A. domesticus) – nymphs 77.1 15.4 3.3 2.2 1.1 0.95
Rusty red roaches (Blatta 69.1 19.0 10.0 2.2 1.2 1.60
lateralis) – nymphs
Six-spotted roaches (Eublaberus 56.6 26.3 13.6 ND 1.65 2.27
distanti) – adults
Fruit flies (Drosophila 69.1 21.0 5.9 3.1 2.2 1.37
melanogaster) – adults
Woodlice/pillbugs (Porcellio 67.8 13.3 3.7 1.6 10.5 0.83
scaber) – adults
Earthworms (Lumbricus terresstris) 83.6 10.5 1.6 0.1 0.6 0.71
ND = Not determined.
a Crude protein measured as nitrogen × 6.25.

fiber than those with a hard exoskeleton like beetles (Finke 2007). The “hard” body parts of some
insects (i.e. the wing covers of beetles or the legs and wings of grasshoppers and other insects) is
largely a result of sclerotized proteins, not chitin. These proteins are hardened via a cross-linking
or tanning process. That is the reason newly-molted insects like mealworms are soft and white in
color. The cross-linking process occurs after molting and results in a darkening and hardening of
the insect cuticle. Insects that are high in fiber are often mistakenly thought of as being high in
chitin, but quantitative data suggest that chitin is only a minor component of most insect species
(Kaspari 1991; Kramer et al. 1995; Finke 2007). While chitin is sometimes thought to be unique to
insects, it is much more widely distributed, being found in fungi, mollusks, fish scales, and most
species of arthropods.

Minerals­and Vitamins
Mineral analyses of invertebrates are shown in Table 41.2. As expected, most insects contain little
calcium and high levels of phosphorus, resulting in a calcium : phosphorus ratio of <1. Some
arthropods, including a few species of insects such as black soldier fly larvae, which have a miner-
alized exoskeleton, are exceptions to this rule. Soldier fly larvae can contain up to 6.6% calcium on
a dry-matter basis depending on diet, while millipedes and isopods contain from 7 to 20% calcium