Organic Value Recovery Solutions LLC
© Organic Value Recovery Solutions 2010
© Organic Value Recovery Solutions 2010
Encyclopedia of Entomology
Springer 2004
10.1007/0-306-48380-7_2920
Nutrient Content of Insects
Mark D. Finke1
(1)
Scottsdale, Arizona, USA
Without Abstract
Insects are an important food source for both animals and humans, and for that reason, reports of their nutrient
composition are found in articles in disciplines ranging from anthropology to zoology. One of the first applications of
the nutrient content of insects involves their use as food for humans. Evidence from archeological sites suggests the
use of tools by early hominids to dig termites from their mounds. The anthropological literature shows that insects
have been, and continue to this day to be, an important human food source. While insects are not routinely eaten in
most western societies, in many other cultures, insects continue to be an important source of nutrients. As such,
nutritional analysis is commonly performed on insects as a means of helping determine the nutrient intake of certain
populations. While a variety of species are commonly eaten, the insects most frequently analyzed include lepidopteran
larvae (mostly members of the family Saturniidae), coleopteran larvae, a number of different species of grasshoppers
and locusts, and several species of termites. The insects most widely consumed by humans are the larvae from three
species of palm weevils (Curculionidae: Rhynchophorus). Indigenous people in Africa, South America, Southeast Asia
and New Guinea have all developed techniques for mass-producing these larvae, which involves cutting down select
species of palms and returning 6 to 10 weeks later to harvest the larvae from the fallen trees. While insects are
sometimes eaten raw, in most cases, insects consumed by humans are processed usually by drying, boiling, frying, or
roasting.
Starting in the 1970s, the nutritional value of a number of insect species have been evaluated as potential foodstuff for
poultry, or other food-producing animals. Extensive analyses, including feeding trials with rats, poultry and fish, have
been published using house fly larvae Musca domestica (L.) silkworm pupae Bombyx mori (L.) and Mormon crickets,
Anabrus simplex Haldeman. In these studies, the nutritional value of dried insect meals have been evaluated when they
were fed as the primary or sole source of dietary protein. These data are especially important as they represent
evaluations of insect protein quality based on both amino acid analysis and animal feeding trials. Most of these data
have been published in the nutrition and animal science journals.
The large number of insect species and the diversity of the environments they inhabit also means they are an important
food source for many terrestrial and aquatic animals. For that reason, the zoological literature contains articles with
nutrient analysis of fresh insects to help evaluate the nutrient intake of wild animals. Termites are the insects most
frequently studied in this regard, presumably because they are the primary food source for a number of highly
specialized mammalian insectivores.
The nutritional content of selected species of cultured insects have also been studied because of their use as food for
captive insectivorous reptiles, birds and mammals kept in zoos. The insect species most commonly utilized for these
purposes include the house cricket, Acheta domesticus, waxworms (larvae of the wax moth Galleria mellonella (L.))
and the larvae from two species of beetles in the family Tenebrionidae: yellow mealworm, Tenebrio molitor (L.), and
superworm Zophobas morio (F.). These analyses are usually performed on raw, whole insects. In an effort to improve
the nutrient composition of insects raised as food for zoo animals, the effect of the residual food in the insect's
gastrointestinal tract has also been studied. This food can have a substantial impact on the nutrient composition of the
insect. For example, the calcium content of fasted house cricket nymphs is about 1,200 mg/kg dry matter, which can be
increased to as much as 18,200 mg/kg dry matter when they are fed a high calcium diet.
There are a number of issues to consider in a review of the literature on the subject of insect nutrient composition. The
first is combining all the information across a wide range of disciplines. A second issue is that insect nutrient
composition is sometimes reported on an as is basis, while other studies report values on a dry weight basis, while
amino acids are commonly reported in milligrams of amino acids per gram of protein. Another factor to consider when
evaluating insect nutrient composition is the effect of handling, preparing and processing of the insects prior to
analysis. Insects prepared for human consumption often have various parts removed, most commonly the wings and
the gastrointestinal contents, so results may not be representative of the whole insect. Additionally, insects consumed
by humans are often processed in some fashion prior to consumption. Processing methods commonly used include
drying, roasting, frying, salting and canning, all of which can have substantial impacts on nutrient composition. Lastly,
when evaluating the nutrient composition of raw whole insects, the effect of any residual food in the insect's
gastrointestinal tract must be considered.
In order to help facilitate comparisons between different studies, all the data (except moisture) in the tables have been
recalculated from the original data to express the information on a dry weight basis. For all tables, a blank indicates the
sample was not analyzed for the particular nutrient. If available, information on how the sample was prepared or
processed prior to analysis is shown. The information presented does not represent a systematic analysis of insects, but
is simply a collection of data available from the literature. As such, it does not adequately represent data for all
families, or even different life stages within a single species, so generalizations from these data concerning the nutrient
composition of a family or order is unwarranted.
Analysis of insects for moisture, protein, fat, ash and fiber is presented. As expected, raw, whole insects generally
contain 55 to 85% moisture. Whole insects with a low moisture content are generally those that also have a high fat
content. As expected, insects processed for human consumption generally contain less moisture than raw insects
because processing usually involves some type of drying to prolong shelf life.
On a dry weight basis, the nutrient in highest concentration is usually protein, which is not surprising given the
protein-rich exoskeleton of insects. Protein contents for raw, whole insects range from 21% for the passalid Oileus
rimator Traqui larvae, to 80% for adult female gypsy moths, Lymantria dispar (L.). Insects processed for human
consumption may exhibit an even wider range as the removal of specific parts will affect the overall nutrient
composition. For example, the hairs or setae commonly found on many species of lepidopteran larvae, which would be
extremely high in protein, are usually removed when the insect is prepared for human consumption.
Fat is the other major component of most insects with raw, whole insects ranging from a low of 2.2% for
Nasuititermes corniger (Motschulsky) worker termites, to a high of 60% for greater wax moth, Galleria mellonella
(L.) larvae. Processing of insects for consumption by humans can dramatically affect reported fat contents in two
ways. Roasting can remove fat from the insect, thereby decreasing the fat content versus that seen in the raw insect,
while frying can increase the insect's fat content. Although there is limited data available, in general, female insects
contain more fat than male insects. Data from various species of Lepidoptera suggests that larvae fed artificial diets are
higher in fat than those fed fresh plant material. For larvae of the stored product pest, the yellow mealworm, Tenebrio
molitor (Linnaeus), providing supplemental moisture increased pre-pupal fat content.
Moisture, protein, fat, fiber and ash content of selected insect species.
Method of preparation
Moisture (%)
Crude protein1 (%)
Crude fat (%)
Fiber (%)
Ash (%)
All values (except moisture) on dry weight basis.
1 Crude protein measured as nitrogen×6.25
aFiber measured as acid detergent fiber
bFiber measured as crude fiber
Lepidoptera
Agrotis infusa (larva)
Roasted
49.2
52.7
39.0
5.3
Anaphe panda (larva)
Intestinal contents and hairs removed
73.9
45.6
35.0
6.5b
3.7
Anaphe venata (larva)
Dried (without hairs)
6.6
60.0
23.2
3.2
Ascalapha odorata (larva)
Whole raw, not fasted
56.0
15.0
12.0b
6.0
Bombyx mori (larva fed artificial diet)
Whole raw, not fasted
82.7
53.8
8.1
6.4a
6.4
Bombyx mori (larva fed mulberry leaves)
Whole raw, not fasted
76.3
64.7
20.8
Bombyx mori (larva fed mulberry leaves)
Whole raw, intestinal contents removed
69.9
62.7
14.2
Bombyx mori (pupa)
Whole raw (dried?)
18.9
60.0
37.1
10.6
Callosamia promethea (larva)
Whole raw, freeze-dried
4.5
51.7
10.5
11.3b
7.2
Catasticta teutila (larva)
Whole raw, not fasted
60.0
19.0
7.0b
7.0
Conimbrasia belina (larva)
Intestinal contents removed then dried
62.0
16.0
11.4b
7.6
Galleria mellonella (larva)
Whole raw, fasted
58.5
34.0
60.0
8.1a
1.4
Heliothis zea (larva fed broad-beans)
Whole raw, fasted
77.4
18.2
Heliothis zea (larva fed artificial diet)
Whole raw, fasted
77.5
30.2
Hyalophora cecropia (larva)
Whole raw, freeze-dried
2.6
56.2
10.5
15.1b
6.1
Imbrasia epimethea (larva)
Smoked and dried
7.0
62.5
13.3
4.0
Imbrasia ertli (larva)
Viscera removed then boiled or roasted, dried and salted
9.0
52.9
12.2
15.8
Imbrasia truncata (larva)
Smoked and dried
7.3
64.7
16.4
4.0
Manduca sexta (larva fed artificial diet)
Whole raw, freeze-dried
4.7
61.0
21.7
9.9b
7.8
Manduca sexta (larva fed fresh plant material)
Whole raw, freeze-dried
4.7
60.7
17.3
8.8 b
8.5
Nudaurelia oyemensis (larva)
Smoked and dried
7.0
61.1
12.2
3.8
Porthetria dispar (adult with eggs)
Whole raw, not fasted
68.6
80.0
44.6
8.0
Pseudaletia unipuncta (larva)
Whole raw, freeze-dried
2.0
55.5
15.2
5.1b
7.0
Spodoptera eridania (larva)
Whole raw, freeze-dried
4.5
57.3
14.6
7.4b
10.3
Spodoptera frugiperda (larva fed artificial diet)
Whole raw, freeze-dried
2.1
59.0
20.6
6.8b
5.7
Spodoptera frugiperda (larva fed fresh plant material)
Whole raw, freeze-dried
3.6
59.3
11.7
12.4b
11.6
Usta terpsichore (larva)
Viscera removed then boiled or roasted, dried and salted
9.2
48.6
9.5
13.0
Xyleutes redtembacheri (larva)
Whole raw, not fasted
43.0
48.0
6.0b
2.0
Coleoptera
Aplagiognathus spinosus (larva)
Whole raw, not fasted
26.0
36.0
15.0b
3.0
Callipogon barbatus (larva)
Whole raw, not fasted
41.0
34.0
23.0b
2.0
Oileus rimator (larva)
Whole raw, not fasted
21.0
47.0
13.0b
2.0
Passalus punctiger (larva)
Whole raw, not fasted
26.0
44.0
15.0b
3.0
Rhyncophorus ferrugineus (larva)
Not reported
70.5
20.7
44.4
Rhyncophorus palmarum (larva)
Whole raw, not fasted
71.7
25.8
38.5
2.1
Rhyncophorus phoenicis (larva)
Incised, fried in oil
10.8
22.8
46.8
2.7
Scyphophorus acupunctatus (larva)
Whole raw, not fasted
36.0
52.0
6.0b
1.0
Tenebrio molitor (adult)
Whole raw, fasted
63.7
65.3
14.9
20.4a
3.3
Tenebrio molitor (larva)
Whole raw, fasted
61.9
49.1
35.0
6.6a
2.4
Zophobas morio (larva)
Whole raw, fasted
57.9
46.8
42.0
6.3a
2.4
Orthoptera
Acheta domesticus (adult)
Whole raw, fasted
69.2
66.6
22.1
10.2a
3.6
Acheta domesticus (nymph)
Whole raw, fasted
77.1
67.2
14.4
9.6a
4.8
Blatella germanica (not specified)
Whole raw, not fasted
71.2
78.8
20.0
4.3
Brachytrupes sp.
Fresh, blanched, inedible parts removed
73.3
47.9
21.3
13.5b
9.4
Crytacanthacris tatarica
Fresh, blanched, inedible parts removed
76.7
61.4
14.2
17.2b
4.7
Gryllotalpa africana
Fresh, blanched, inedible parts removed
71.2
53.5
21.9
9.7b
9.4
Oxya verox
Whole raw, dried
29.8
64.2
2.4
3.4
Oxya yezoensis
Whole raw, not fasted
65.9
74.7
5.7
6.5
Sphenarium histro (nymphs & adults)
Whole raw, not fasted
77.0
4.0
12.0b
2.0
Zonocerus sp.
Whole raw, not fasted
62.7
71.8
10.2
6.4b
3.2
Isoptera
Cortaritermes silvestri (worker)
Whole raw, not fasted
77.8
48.6
6.9
8.5
Macrotermes bellicosus (alate)
Dewinged, raw
6.0
34.8
46.1
10.2
Macrotermes subhyalinus (alate)
Dewinged, fried in oil
0.9
38.8
46.5
6.6
Nasutitermes corniger (soldier)
Whole raw, not fasted
69.6
58.0
11.2
34.8a
3.7
Nasutitermes corniger (worker)
Whole raw, not fasted
75.3
66.7
2.2
27.1a
4.6
Procornitermes araujoi (worker)
Whole raw, not fasted
78.1
33.9
16.1
3.5
Syntermes ditus (worker)
Whole raw, not fasted
79.7
43.2
3.4
17.1
Hymenoptera
Aphis melifera (adult female)
Whole raw, not fasted
65.7
60.0
10.6
17.4
Aphis melifera (adult male)
Whole raw, not fasted
72.4
64.4
10.5
17.8
Aphis melifera (larva)
Whole raw, not fasted
76.8
40.5
20.3
1.3a
3.4
Atta mexicana (reproductive adult)
Whole raw, not fasted
46.0
39.0
11.0b
4.0
Oecophylla smaragdina
Fresh, blanched inedible parts removed
74.0
53.5
13.5
6.9b
6.5
Oecophylla virescens
Inedible parts removed
78.3
41.0
26.7
6.0
Polybia sp. (adult)
Whole raw, not fasted
63.0
13.0
15.0b
6.0
Diptera
Copestylum ann & haggi (larva)
Whole raw, not fasted
37.0
31.0
15.0b
8.0
Drosophila melanagaster (adult)
Whole raw, not fasted
67.1
56.3
17.9
5.2
Hermetia illucens (larva)
Dried, ground, not fasted
3.8
47.0
32.6
6.7b
8.6
Musca autumnalis (pupa)
Dried, ground, not fasted
51.7
11.4
28.9
Musca domestica (pupa)
Dried, ground, not fasted
61.4
9.3
11.9
Hemiptera
Acantocephala declivis (nymphs & adults)
Whole raw, not fasted
35.0
45.0
18.0b
1.0
Edessa petersii (nymphs & adults)
Whole raw, not fasted
37.0
42.0
18.0b
2.0
Euchistus egglestoni (nymphs & adults)
Whole raw, not fasted
35.0
45.0
19.0b
1.0
Pachilis gigas (nymphs & adults)
Whole raw, not fasted
64.0
22.5
7.5b
3.5
Hoplophorion monograma (nymphs & adults)
Whole raw, not fasted
64.0
14.0
18.0b
3.0
Umbonia reclinata (nymphs & adults)
Whole raw, not fasted
29.0
33.0
13.0b
11.0
As expected, most insects contain only small amounts of ash because they lack the internal calcified skeleton found in
most vertebrates. An exception is the puparia of the face fly, Musca autumnalis DeGeer. Unlike most insect species
where the cuticle consists largely of sclerotized protein, the puparia of the face fly is calcified and so contains 63% ash
on a dry weight basis versus 3.7% ash for the puparia of the house fly, Musca domestica (L.).
It is frequently reported that soft-bodied insects contain less fiber than those with a hard exoskeleton, but the limited
data available and the use of several different techniques to measure fiber prevents a critical evaluation of this
assumption. Additionally, the contribution of the gastrointestinal contents can have a marked effect and is likely the
reason for the high fiber values seen for many of the insect species. Looking at the data for Tenebrio molitor, it does
appear that the soft bodied larva has less fiber than the heavily sclerotized adult beetle. The structural similarity
between chitin (N-acetyl-D-glucoamine linked by β-1-4 bonds) and cellulose (β-D-glucopyranose linked by β-1-4
bonds) is the reason it is often assumed that the fiber measured in insects consists solely of chitin. Given the physical
characteristics of sclerotized proteins and the fact that amino acids have been detected in the acid detergent fiber
residue, it seems likely that the fiber (measured as either crude fiber or acid detergent fiber) in fasted insects represents
both chitin and sclerotized protein.
As expected, insects contain little calcium and high levels of phosphorus. While most wild-caught insects also appear
to be low in calcium, in general, the values are somewhat higher than those reported for captive-raised insects. High
calcium levels have been reported in only a few species of insects. Insects that have been shown to contain substantial
quantities of calcium include stoneflies (1.15% dry matter basis), housefly pupa, Musca domestica (0.93% dry matter
basis), from larvae raised in poultry manure containing 5.1% calcium, and the previously mentioned Musca
autumnalis puparia. Presumably, wild living animals feeding primarily on insects obtain sufficient calcium by varying
the prey species consumed, eating insects which have consumed a high-calcium diet and by ingesting soil particles
adhering to the prey animals. Lastly, the calcium content of wax worms (Galleria mellonella larvae), house crickets
(Acheta domesticus), mealworms (Tenebrio molitor larvae) and silkworms (Bombyx mori larvae) can all be increased
5 to 20-fold when fed a high calcium diet. This increase in calcium appears to be solely due to the residual food in the
gastrointestinal tract with little of the calcium being incorporated into the insect's body.
Mineral content of selected insect species.
Ca (mg/kg)
P (mg/kg)
Mg (mg/kg)
K (mg/kg)
Na (mg/kg)
Cl (mg/kg)
Fe (mg/kg)
Zn (mg/kg)
Cu (mg/kg)
Mn (mg/kg)
Se (mg/kg)
Lepidoptera
Anaphe venata (larva)
400
7300
500
11500
300
100
100
10
400
Bombyx mori (larva fed artificial diet)
1020
13700
2880
18270
2750
3580
95
178
21
25
0.8
Bombyx mori (pupa)
1950
5840
2550
320
284
2
9
Conimbrasia belina (larva)
1740
5430
1600
10240
10320
310
140
9
39
Galleria mellonella (larva)
590
4700
760
5320
400
1540
50
61
9
3
0.3
Imbrasia epimethea (larva)
2250
6660
4020
12580
750
130
111
12
58
Imbrasia ertli (larva)
550
6000
2540
12030
24170
21
15
34
Imbrasia truncata (larva)
1320
8420
1920
13490
1830
87
111
14
32
Nudaurelia oyemensis (larva)
1490
8710
2660
11070
1400
97
102
12
55
Usta terpsichore (larva)
3910
7650
590
32580
33380
390
253
26
67
Coleoptera
Phyllophaga rugosa (adult)
430
1900
11510
790
170
Rhyncophorus ferrugineus (larva)
15630
146
Rhyncophorus palmarum (larva)
1000
4800
3100
6800
2600
34
111
26
18
Rhyncophorus phoenicis (larva)
2080
3520
330
22090
450
147
265
16
8
Tenebrio molitor (adult)
640
7630
1670
9370
1740
5260
60
127
21
11
0.4
Tenebrio molitor (larva)
440
7480
2100
8950
1410
4910
54
137
16
14
0.7
Zophobas morio (larva)
420
5630
1180
7510
1130
3610
39
73
9
10
0.3
Orthoptera
Acheta domesticus (adult)
1320
9580
1090
11270
4350
7370
63
218
20
37
0.6
Acheta domesticus (nymph)
1200
11000
990
15370
5890
9690
93
297
22
39
0.4
Brachytrupes sp.
3300
6120
10360
2120
539
Crytacanthacris tatarica
1180
6450
9330
1370
128
Gryllotalpa africana
2630
8820
9300
3370
1448
Isoptera
Macrotermes bellicosus (alate)
450
280
1170
Macrotermes subhyalinus (alate)
400
4420
4210
4810
19880
76
137
644
Nasutitermes corniger (soldier)
3700
2900
1500
5800
600
1001
164
33
115
0.5
Nasutitermes corniger (worker)
2000
4000
1300
6100
2400
394
144
52
32
Hymenoptera
Aphis melifera (larva)
590
7720
910
11590
550
3750
56
69
17
3
0.3
Oecophylla smaragdina
1840
7920
8530
2160
219
Oecophylla virescens
800
9360
1220
9570
2700
1090
169
22
63
Diptera
Drosophila melanogaster (adult)
1400
11000
1300
454
147
9
16
Musca autumnalis (pupa)
24800
27400
11500
5500
1800
250
270
15
660
Musca domestca (pupa)
9300
14300
8800
5600
465
275
34
370
All insects contain high levels of phosphorus, which results in a calcium:phosphorus ratio of less than one. For most
monogastric animals, phosphorus from animal sources is virtually 100% available, while plant-based phytate
phosphorus is approximately 30% available. The phosphorus in most insects is likely to be readily available as was
shown for Musca autumnalis puparia with an availability of 92%. Most insects contain substantial levels of the other
macro-minerals, magnesium, sodium, potassium and chloride. The very high sodium levels for the three species of
lepidopteran larvae (Imbrasia ertli Rebel, Usta Terpsichore M. & W., and Conimbrasia belina Westwood) and for the
termite, Macrotermes subhyalinus Rambur, is probably a result of salt added during processing.
Most insects appear to be good sources of the trace minerals of iron, zinc, copper, manganese and selenium. For
insects prepared for human consumption, some of the elevated levels of iron and copper are likely the result of metal
that has leached from the cookware. Mineral composition in general probably largely reflects the food sources of the
insect, both that which is present in the gastrointestinal tract and that which is incorporated into the insect's body as a
result of the food it consumed. Studies of wild insects show both seasonal variation as well as variations between
different populations of the same species living in the same general area. While it is assumed the availability of these
trace minerals is good, there are no published studies measuring the availability of trace minerals in insects.
There are a number of published reports on the amino acid composition of insects but recovery (measured as the
percent of total nitrogen as amino acids) ranges from approximately 40 to 95%. This could be the result of the
presence of large amounts of nitrogen-containing compounds other than amino acids, such as chitin, or methodology
problems in the analysis. Because many papers report only a limited number of amino acids (usually those considered
essential for humans), it is impossible to calculate recoveries and evaluate the accuracy of the data. In spite of these
issues, there are sufficient data to show that insects are a good source of amino acids and provide good quantities of
the essential amino acids. Because some of these amino acids are part of the exoskeleton and may be sclerotized, they
may not be readily available when consumed. The only two studies measuring protein digestibility of insect protein in
rats reported values of 86% and 89% values, which are only slightly lower than the values reported for other animal
protein sources (egg 95%, beef 98%, and casein 99%). Thus, it is likely that overall, the digestibility of insect protein,
while slightly lower than that of more traditional animal protein sources such as egg, meat and milk, is higher than that
of many vegetable-based proteins.
Crude protein and amino acid content of selected insect species.
Crude protein (%)
Ala (%)
Arg (%)
Asp (%)
Glu (%)
Gly (%)
His (%)
Ile (%)
Leu
(%)
Lys (%)
Met (%)
Cys (%)
Phe (%)
Tyr (%)
Pro (%)
Ser (%)
Thr (%)
Trp (%)
Val
(%)
Amino acid analyses from a variety of papers provide no common estimate of the first limiting amino acid for insect
protein. While tryptophan is the amino acid most commonly cited as first limiting, all of the amino acids known to be
essential for humans have been reported as first limiting. They include histidine, isoleucine, leucine, lysine, total sulfur
amino acids (methionine plus cystine), total aromatic amino acids (phenylalanine plus tyrosine), threonine and valine.
While it is unlikely that all species of insects would have the same first limiting amino acid, the range of first limiting
amino acids reported is difficult to understand, but may be due to the analytical techniques used. Accurate analysis of
methionine, cystine and tryptophan requires two separate hydrolysis versus that used for the other amino acids and the
low values reported in some papers suggest this was not always done. Another issue confounding the identification of
the limiting amino acid is the use of a variety of different standards. Insect amino acid patterns have been compared to
World Health Organization recommended patterns for both adults and preschoolers, United Nations Food and
Agriculture Organization recommended patterns for pre-school children as well as comparisons to egg protein, or other
reference proteins.
In contrast to the variability obtained when calculating the first limiting amino acid, results from feeding studies have
been very consistent. When diets containing insect protein from housefly pupae, yellow mealworm larvae, or Mormon
crickets were fed to young, growing rats, in all three studies, methionine was shown to be the first limiting amino acid.
While methionine was the first limiting amino acid for the growth of rats, when Mormon cricket meal was used as the
sole source of dietary protein, no additional response was observed at maintenance, suggesting a different amino acid
(not yet identified) was first limiting. As such, insect protein is likely to have a different first limiting amino acid when
compared to human standards for either growth or maintenance. The high choline content of most insects also needs to
be considered when determining the first limiting amino acid in insects, because high dietary choline levels can reduce
the dietary requirement for methionine.
Unlike birds, reptiles, and fish, mammals are ureotelic, excreting urea as an end product of protein metabolism.
Arginine is synthesized during this process, which is why the arginine requirement for growing rats is low relative to
that for birds or fish. This is why Mormon cricket meal was shown to be co-limiting in the amino acids arginine and
methionine when fed to broiler chicks, while only methionine was first limiting when fed to growing rats. As such, the
use of insects in poultry or fish diets may require different amino acid supplementation than when used in diets for
mammals.
In general, feeding trials using house fly larvae and pupae, face fly pupae, soldier fly larvae, Hermetia illucens (L.),
Mormon crickets, house crickets, yellow mealworms, and various species of lepidopteran larvae have resulted in good
growth of rats, chickens and several species of fish. This suggests that insect protein is readily available with protein
quality values similar to, or slightly higher than, that of fish meal or soybean meal. However, in five separate studies,
(three that used silkworm pupal meal) dried insect meals have produced poor results. In most of these studies, the poor
growth appears to be a result of low food consumption. These results may be due to the presence of oxidized fats.
Because dried insect meals are generally high in unsaturated fatty acids, they are susceptible to oxidation if not treated
with an antioxidant during drying and storage. Another possibility is the presence of a compound in the insect meal,
which negatively affects palatability. In the wild, many insect species are known to sequester compounds from their
foodplants, which cause them to be unpalatable or toxic. A third possibility is the effect of some unknown anti-
nutritional factor present in some species of insects. While there is little work in this area, a thiaminase recently has
been discovered in both African silkworm pupae (Anaphe) and domestic silkworm larvae (Bombyx mori).
There is only very limited data available for vitamin analyses of insects. While several species of lepidopteran larvae
and the soldiers of one species of termites (Nasutitermes corniger) contain significant quantities of preformed vitamin
A (retinol), in general, insects do not appear to contain much preformed vitamin A. Insects use a variety of retinoids
for vision, which they synthesize from carotenoids in their food. As these retinoids are present only in the insect eye,
whole body levels of retinoids are usually very low. There is a single report that honey bee (Aphis mellifera) larvae and
pupae contain extremely high levels of preformed vitamin A (50,000 to 154,600 µg retinol/kg dry weight), but the
analytical procedure used is not specific for retinol. More recent analysis using high pressure liquid chromatography
detected no retinol in honey bee larvae or pupae, and only low levels (850 to 930 µg retinol/kg) in adult bees.
Vitamin content of selected insect species.
Vitamin A (µg retinol/kg)
β-Carotene (ug/kg)
Vitamin E (mg α-tocopherol/kg)
Thiamin (mg/kg)
Riboflavin (mg/kg)
Niacin
(mg/kg)
Pantothenate (mg.kg)
Pyridoxine (mg/kg)
Folate (mg/kg)
Biotin (mg/kg)
Vitamin B12 (ug/kg)
Choline
(mg/kg)
ND – Not Detected
Lepidoptera
Bombyx mori (larva fed artificial diet)
2740
ND
34
19.1
54.3
152
125
9.5
4.1
1.4
ND
6523
Bombyx mori (pupa)
11
Conimbrasia belina (larva)
60
10
5.8
49.8
119
Galleria mellonella (larva)
40
ND
21
5.6
17.6
90
49
3.1
1.1
0.7
ND
3953
Imbrasia epimethea (larva)
470
82
1.8
43.0
118
ND
0.7
0.1
0.3
0.2
Imbrasia ertli (larva)
Imbrasia truncata (larva)
330
71
2.9
55.0
118
ND
0.4
0.4
0.5
0.3
Nudaurelia oyemensis (larva)
320
68
1.6
34.0
101
ND
0.5
0.2
0.3
0.2
Porthetria dispar (adult with eggs)
100
149
Usta terpsichore (larva)
40.4
20.9
3
Coleoptera
Rhyncophorus ferrugineus (larva)
2.7
14.6
125
Rhyncophorus palmarum (larva)
18000
347
Rhyncophorus phoenicis (larva)
33.8
25.1
34
Tenebrio molitor (adult)
ND
ND
ND
2.7
23.4
155
66
22.4
3.8
0.8
15.4
6671
Tenebrio molitor (larva)
240
ND
20
6.3
21.3
107
69
21.1
4.1
0.8
12.3
4839
Zophobas morio (larva)
290
ND
21
1.5
17.8
77
46
7.6
1.6
0.8
10.1
4124
Orthoptera
Acheta domesticus (adult)
240
ND
43
1.2
110.7
125
75
7.5
4.9
0.6
174.3
4932
Acheta domesticus (nymph)
140
ND
28
0.8
41.5
143
115
7.6
6.3
0.2
380.8
4776
Blatella germanica (not specified)
300
179
Brachytrupes sp.
9.7
66.7
86
Crytacanthacris tatarica
8.1
24.5
286
Gryllotalpa africana
6.9
65.6
167
Oxya verox
3.4
78.4
100
Isoptera
Macrotermes subhyalinus (alate)
1.3
11.5
46
Nasutitermes corniger (soldier)
20400
84
Nasutitermes corniger (worker)
ND
ND
Hymenoptera
Aphis
melifera (adult female)
850
27
Aphis melifera (adult male)
930
10
7258
Aphis melifera (larva)
ND
ND
ND
17.7
39.2
158
51
5.1
ND
1.0
ND
Oecophylla smaragdina
9.2
33.8
130
Diptera
Drosophila melanagaster (adult)
ND
15
While commercially raised insects appear to contain little or no β-carotene, most wild-caught insects contain a variety
of carotenoids (astaxanthin, α-carotene, β-carotene, lutein, lycopene, zeaxanthin, and others), which they accumulate
from their food. Most species of vertebrates can convert some of these carotenoids to retinol, so insects containing
high levels of carotenoids may be a significant source of vitamin A for insectivorous vertebrates.
There is little data on the vitamin E content of insects, but levels are generally low. Wild-caught insects appear to
contain more vitamin E than cultured insects, which likely reflects differences in their dietary intake. When
mealworms (Tenebrio molitor larvae) or house crickets (Acheta domesticus) were fed diets high in vitamin E for seven
days, there was only a small increase in the vitamin E content of the crickets and the mealworms. It is not clear
whether this reflects vitamin E absorbed by the insect, or is simply a result of the dietary vitamin E retained in the
gastrointestinal tract.
B-vitamin analysis of insects is very limited and most of the available data is for thiamin, riboflavin and niacin. All
insects tested contained substantial quantities of most of the B-vitamins and choline. It should be noted that several B-
vitamins (most notably thiamin and, to a lesser degree, pyridoxine and folic acid) are not heat stable so, processing
insects by canning, roasting or boiling is likely to result in a reduction of these vitamins. While insects appear to be a
good source of most B-vitamins, a number of insects appear to contain low levels of thiamin. Some of these low levels
are likely an effect of heat processing, although the low levels seen for house crickets and superworms (Zophobas
morio larvae) are for raw, whole insects. Recently, wild African silkworm pupae (Anaphe) have been shown to contain
high levels of an enzyme which results in the destruction of thiamin (Vitamin B1). This thiaminase was shown to be
relatively heat stable and appears to be responsible for an acute seasonal ataxia reported in humans in Nigeria that was
previously linked to Anaphe consumption.
There are numerous reports on the fatty acid composition of various insect species, and all of the insects tested
contained the essential fatty acid linoleic acid (18:2). There appears to be no consistent pattern in fatty acid profiles
across a variety of insect species, although all species contained significant quantities of palmitic, oleic, linoleic and
linolenic acid. Some insects have also been shown to contain minor amounts of other fatty acids including lauric acid
(12:0), myristoleic acid (14:1), heptadecanoic acid (17:0), heptadecenoic acid (17:1), arachidonic acid (20:4) and
benhic acid (22:0).
Crude fat content and major fatty acids of selected insect species.
Crude fat (%)
Myristic acid (14:0)
Palmitic acid (16:0)
Palmitoleic acid (16:1)
Stearic acid
(18:0)
Oleic acid (18:1)
Linoleic acid (18:2)
Linolenic acid (18:3)
Arachidic acid (20:0)
Other fatty acids1
ND – Not Detected
1 Other major fatty acids reported as % followed by fatty acid formula
Lepidoptera
Bombyx mori (larva fed artificial diet)
8.1
ND
0.98
0.03
0.72
1.86
2.05
0.83
0.06
Bombyx mori (pupa)
37.1
9.72
2.60
13.69
1.56
9.53
Galleria mellonella (larva)
60.0
0.10
19.18
1.23
0.82
29.88
3.66
0.27
0.07
0.07%–17:1
Heliothis zea (larva fed broad-beans)
18.2
0.10
3.80
0.20
0.40
3.30
1.50
5.50
Heliothis zea (larva fed artificial diet)
30.2
0.10
7.60
2.90
0.10
12.90
0.70
0.00
Imbrasia epimethea (larva)
13.3
0.08
3.09
0.08
2.94
1.12
0.93
4.67
Imbrasia ertli (larva)
12.2
0.12
2.68
0.05
0.24
2.44
1.34
4.63
0.11%–17:0; 0.06%–12:0
Imbrasia truncata (larva)
16.4
0.03
4.03
0.03
3.56
1.21
1.25
6.04
Nudaurelia oyemensis (larva)
12.2
0.02
2.66
0.07
2.82
0.68
0.70
4.34
Usta terpsichore (larva)
9.5
0.22
2.60
0.01
0.16
2.58
0.27
0.71
2.82%–17:0
Coleoptera
Rhyncophorus phoenicis (larva)
46.8
1.17
16.83
0.14
14.03
12.16
0.94
0.28
0.65%–17:0
Tenebrio molitor (adult)
14.9
0.22
2.34
0.17
0.72
4.93
3.77
0.11
0.06
0.06%–17:0; 0.06%–17:1
Tenebrio molitor (larva)
35.0
0.76
6.01
0.92
1.02
14.15
9.13
0.37
0.08
0.08%–17:1
Zophobas morio (larva)
42.0
0.40
12.54
0.17
2.99
15.68
7.81
0.26
0.10
0.17%–17:0; 0.17%–17:1
Orthoptera
Acheta domesticus (adult)
22.1
0.13
5.06
0.29
1.88
5.00
7.44
0.19
0.13
0.10%–22:0
Acheta domesticus (nymph)
14.4
0.08
2.66
0.14
1.27
2.79
4.80
0.18
0.11
Isoptera
Macrotermes bellicosus (alate)
46.1
0.08
21.45
0.96
5.92
15.87
1.77
Macrotermes subhyalinus (alate)
46.5
0.42
15.35
0.65
4.42
20.04
1.40
0.19
1.21%–17:0; 0.23%–14:1;
Nasutitermes corniger (soldier)
11.2
0.48
0.85
0.11
1.33
3.66
1.24
1.09
0.43
1.03%–20:4; 0.49%–22:0
Nasutitermes corniger (worker)
2.2
0.09
0.21
0.05
0.28
1.08
0.33
ND
0.04
0.04%–12:0; 0.03%–22:0
Hymenoptera
Aphis melifera (larva)
20.3
0.52
6.34
0.10
1.83
7.84
0.15
0.16
0.10
0.07%–12:0
In a review of insect fatty acid patterns, Thompson reported that several insect orders appeared to have unique fatty
acid profiles. These peculiarities included relatively high levels of myristic acid (14:0) in Hemiptera, and palmitoleic
acid (16:1) in Diptera. It also appears that linoleic acid (18:2) and linolenic acid (18:3) were virtually absent in
Dictyoptera (Mantodea, Blattodea). The data are not shown in the table because crude fat and fatty acid content as a
percent of body weight could not be calculated.
In general, it appears that insect fatty acid levels reflect a combination of insect fatty acid synthesis (certain pathways
that may be unique for certain species or orders) and the fatty acid composition of the insect's diet. For insects that
feed on a single foodplant, the values in the table are probably typical for all members of the species. In contrast, the
fatty acid content of generalist feeders like the house cricket, Acheta domesticus, is likely to vary widely depending on
the diet being fed. In addition, the data for Rhyncophorus phoenicis (F.) and Macrotermes subhyalinus is for insects
that were fried prior to analysis. As such, these analyses reflect both the fat naturally in the insect and that from the
cooking oil.
References
Barker, D., M. P. Fitzpatrick, and E. S. Dierenfeld. 1998. Nutrient composition of selected whole invertebrates. Zoo
Biology 17: 123–134.
Bukkens, S. G. F. 1997. The nutritional value of edible insects. Ecology of Food and Nutrition 36: 287–319.
DeFoliart, G. R. 1989. The human use of insects as food and as animal feed. Bulletin of the Entomological Society of
America 35: 22–35.
Feltwell, J., and M. Rothschild. 1974. Carotenoids in thirty-eight species of Lepidoptera. Journal of Zoology 174:
441–465.
Finke, M. D., G. R. DeFoliart, and N. J. Benevenga. 1987. Use of a four-parameter logistic model to evaluate the
protein quality of mixtures of Mormon cricket meal and corn gluten meal in rats. Journal of Nutrition 117: 1740–1750.
Finke, M. D. 2002. Complete nutrient composition of commercially raised invertebrates as food for insectivores. Zoo
Biology 21: 269–285.
Ramos-Elorduy, J., J. M. P. Moreno, E. E. Prado, M. A. Perez, J. L. Otero, and O. L. de Guevara. 1997. Nutritional
value of edible insects from the state of Oaxaca, Mexico. Journal of Food Composition and Analysis 10: 142–157.
Thompson, S. N. 1973. A review and comparative characterization of the fatty acid compositions of seven insect
orders. Comparative Biochemistry and Physiology 45B: 467–482.