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Abstract and Figures

The potential nutritional value of insects in general and the common house cricket, Acheta domesticus, in particular in human diets has long been recognized. In addition to providing a rich source of high quality proteins for human consumption, crickets and other related insects such as grasshoppers and locusts offer several other advantages as human food sources: they have a short lifespan, produce numerous offspring, are amenable to human cultivation, and can flourish under a wide range of environmental conditions. The main aims of the present study were two-fold: to compare the yield of crickets raised on four different diets, and to determine the amino acid, fatty acid, and mineral and trace element content of crickets grown under the best of these diets. The four diets were: aromatic-arboreal (AAD), dairy cow diet (DCD), DCD supplemented with yeast, and human refuse diet (HRD). The greatest yield (0.45g per 10g of feed) and highest survival (47.5%) of A. domesticus was achieved with HRD when grown for 9 weeks in 24 hours of daylight. The protein content of crickets raised on all four diets ranged from 56.2 to 60.0% of dry weight, and in all cases the essential amino acid score of the proteins approximated or exceeded the World Health Organization protein standard. The crickets contained 63-122 mg fatty acid per g dry weight, most of which was accounted for by palmitic acid, oleic acid and the two fatty acids that are essential in humans, namely linoleic acid and α-linolenic acid. Crickets grown on any one of the diets contained significant quantities of the following minerals or trace elements: calcium (366-480 μg per g dry weight), copper (8.5-9.2 μg per g), iron 16.2-26.7 μg per g), and magnesium (255-306 μg per g). These data support the contention that crickets contain quantities of many nutrients that are essential to humans and show that the insect represents a commercially feasible source of food for certain human populations
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House Cricket Small-scale Farming
Dept. of Biology, Padova University, Via U. Bassi 58/b, 35121 Padova, Italy
Dept. of Biochemistry and Molecular Biology, University of New Mexico School of
Medicine, Albuquerque, NM, USA
Ross Products Division, Abbott Laboratories, Columbus, OH, USA
NIOSH Laboratory, Cincinnati, OH, USA
The potential nutritional value of insects in general and the common house
cricket, Acheta domesticus, in particular in human diets has long been recognized.
In addition to providing a rich source of high quality proteins for human con-
sumption, crickets and other related insects such as grasshoppers and locusts
offer several other advantages as human food sources: they have a short life
span, produce numerous offspring, are amenable to human cultivation, and can
flourish under a wide range of environmental conditions. The main aims of this
study were two: compare the yield of crickets raised on four different diets, and
determine the amino acid, fatty acid, and mineral and trace element content of
crickets grown under the best of these diets. The four diets were: aromatic-arbo-
real (AAD), dairy cow diet (DCD), DCD supplemented with yeast, and human
refuse diet (HRD). The greatest yield (0.45 g per 10 g of feed) and highest sur-
vival (47.5%) of A. domesticus was achieved with HRD when grown for 9 weeks
in 24 hours daylight. The protein content of crickets raised on all four diets ranged
from 56.2 to 60.0% dry weight, and in all cases the essential amino acid score of
the proteins approximated or exceeded the World Health Organization protein
standard. The crickets contained 63–122 mg fatty acid per g dry weight, most of
which was accounted for by palmitic acid, oleic acid, and the two fatty acids
essential for humans, namely linoleic acid and α-linolenic acid. Crickets grown
on any one of the diets contained significant quantities of the following miner-
als or trace elements: calcium (366–480 µg per g dry weight), copper (8.5–9.2 µg
per g), iron (16.2–26.7 µg per g), and magnesium (255–306 µg per g). These data
516 Ecological Implications of Minilivestock
support the contention that crickets contain quantities of many nutrients that
are essential to humans and show that the insect represents a commercially fea-
sible source of food for human populations.
Key Words: Acheta domesticus, cricket, minilivestock, small-scale farming, food
web optimization, edible insects, recycling wastes, natural resources, biodiversity,
sustainable farming, food security, nutrients, fatty acids, minerals, amino acids
The main purpose of this study was to test the hypothesis that cultivation of the
common cricket, Acheta domesticus (Plate X, 6), might offer human populations
worldwide an economically feasible, sustainable, and nutritionally sound source
of food. Several investigators have simulated large, insect-based production
systems such as Tribolium confusum (Kok et al., 1990), using a variety of food
sources (Larde, 1989). Several non-European human populations use different
species of Orthoptera as a food source in Africa (Malaisse, 2004, this volume),
Australia (Meyer-Rochow and Changkija, 1997) Latin America, (Onore, 1997;
Ramos-Elorduy 1997; Ruddle, 1973), and North America (Menzel and D’Aluisio,
The high nutrient quality of the proteins of Acheta domesticus (L.) is widely
recognized. For example, Nakagaki and coworkers (1987) demonstrated that
crickets are an excellent food source for chicks and Finke and collaborators (1989)
showed that weanling rats grow well on crickets. One of these same research
groups (Finke, 2002) also demonstrated that invertebrates in general are an ex-
cellent food source for raising various insectivores. Furthermore, protein com-
monly accounts for as much as 60% dry weight of invertebrates (DeFoliart, 1992).
This study sought to identify a food source that would be suitable for rais-
ing crickets in an economically feasible and environmentally sensitive and sus-
tainable manner. Four different insect diets were compared: (1) an aromatic-
arboreal diet (AAD), (2) a dairy cow diet (DCD), (3) the dairy cow diet supple-
mented with yeast (DCD+Y), and (4) a human refuse diet (HRD) (Table 27.1).
The aromatic-arboreal diet was constituted from organic matter found in abun-
dance in the woody/bushy territory of the Mediterranean, from which common
plants with high nitrogen content and bacteriostatic/bactericidal activity were
selected (Fenaroli, 1963). The DCD and DCD + Y diets were based largely on
cereals fed to dairy cows (without the antiobiotics and integrators usually added).
We used yeast as an additive in the DCD-based diet because preliminary stud-
ies had shown that it contains important growth factors (McFarlane et al., 1959;
Patton, 1967) which would enhance cricket yield. The human refuse diet was
selected because of the availability of large quantities of this material and be-
cause of agricultural politics. Other considerations that factored into our choice
of diets were cost, impact on the environment, and sustainability. In comparing
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 517
the various diets used to raise the crickets, we assessed different cricket crowding
conditions and the sustainability of cropping systems to produce the needed feed.
The second specific aim of the study was to compare the nutrient content of
crickets raised on the four diets, with specific attention to essential amino acids,
fatty acids, and mineral and trace elements. Our data identified a diet that sup-
ports a high yield of crickets and that can provide human diets with substantial
quantities of essential nutrients.
Table 27.1: Diet composition (in grams)
Ingredients Aromatic-Arboreal Diet (AAD) grams
False acacia (Robinia pseudacacia) 4.1
Yeast (Saccharomyces cerevisiae) 2.9
Basel (Ocimum basilicum) 1.3
Sage leaves (Salvia officinalis) 1.0
Hazel leaves (Corylus avellana) 0.5
Maple leaves (Acer campestre) 0.2
Sum 10.0
Ingredients Dairy Cow Diet with Yeast (DCD+Y) grams
Soybean flour (Glycine max) 2.07
Lucern (Medicago sativa) 1.78
Corn flour (Zea mays) 1.46
Wheat flour (Triticum durum) 1.31
Yeast (Saccharomyces cerevisiae) 1.15
Sugar beet (Beta vulgaris var. esculenta) 1.13
Silo 1.10
Sum 10.00
Ingredients Dairy Cow Diet (DCD) grams
Soybean flour (Glycine max) 2.26
Lucern (Medicago sativa) 1.97
Corn flour (Zea mays) 1.65
Wheat (Triticum durum) 1.50
Sugar beet (Beta vulgaris var. esculenta) 1.32
Silage corn 1.30
Sum 10.00
Ingredients of Human Refuse Diet (HRD) grams
Fruits and vegetables (peel and leftover) 3.4
Rice and pasta 2.7
Pork and beef meat 1.1
Bread 1.1
Cheese skins 1.1
Yolk 0.6
Sum 10.0
518 Ecological Implications of Minilivestock
Materials and Methods
The crickets employed in this study belong to the species Acheta domesticus (L.).
They were purchased from Livefood UK, The Acres, Gills Lane, Rooks Bridge,
Somerset; Two colonies of 70 individuals each were reared
to obtain eggs and for a preliminary assessment of food preferences. At the time
of egg hatching, individual organisms of the same day were collected in order to
establish colonies and to measure food preferences, optimal population density,
optimal rearing diets, and protein content and quality. Overall, 18 colonies com-
prised 50 to 250 individuals were established over a period of 18 months. Two of
our aims were to compare the quality of the various feeds in terms of cricket
production and to compare the energy efficiency conversion index (ECI) of our
cricket populations with that reported for more conventional livestock.
Rearing Conditions
Colonies were reared in terrariums 0.50 m × 0.25 m × 0.35 m (total capacity 44
liters) and constructed of glass and wood. Each rearing box was covered with a
0.75 mm metal screen to prevent insects from escaping. The terrariums con-
tained a nesting box (10 cm × 10 cm × 10 cm) filled with a mixture of sand, earth,
and peat. Four egg cardboards to increase the walking surface were also settled
inside the terrariums, together with test tubes filled with water to ensure hu-
midity and a 25-watt lamp to ensure light and to maintain a suitable tempera-
ture (30.5°C). The crickets were exposed to 24 hours of light to optimize produc-
tivity, as suggested by Comby (1991) and Nakagaki and DeFoliart (1991). A.
domesticus were fed ad libidum water and dry, finely ground feed. The period of
observation was between 2 and 3 months for each colony.
During the rearing time, crickets were periodically counted and weighed to
determine the extent of crowding and growth rates.
Assessment of Feed Preferences
Two colonies per diet were established to conduct a preliminary test of feed
preference. Fifty newly hatched crickets of the same age were used to initiate
each colony. We chose to use relatively few individuals so as to provide optimal
access to food and water and to minimize crowding that might elicit abnormal
behavior. Finely ground feed was given to prevent rotting and to optimize hy-
gienic conditions. The feeds were oven dried at 90°C for 48 hours, then finely
ground before placing in the terrariums. Feed consumption was monitored over
a 60-day period, offering 40 different foods in groups of 16 substrates, and chang-
ing them randomly every 5 days; that is, each group of foods was left in the
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 519
colony for 5 days. Accordingly, we were able to make 192 measurements, testing
each food at least four times, most of them five times. Food consumption was
expressed as the difference between the offered and unconsumed foods over a
five-day interval. We noticed that approximately 10% of the offered food was
dispersed in the box; this loss was measured when the terrariums were cleaned
at the end of each week and taken into consideration when food consumption
was calculated.
Feed Consumption, Efficiency Conversion Index (ECI), and Mortality
Thirteen colonies, each starting with 250 individuals, were grown to test these
diets. Every 2–3 days cricket diet consumption was measured as just described
to ascertain “feed preferences”. Based on these measurements, efficiency con-
version and mortality were determined.
The conversion efficiency of ingested feed was calculated according to
Waldbauer (1968): ECI = 100 * [biomass gained/feed consumed]. At least 30
crickets where taken randomly and weighed. Mortality was recorded as de-
crease in population in each colony on the day of weighting.
Nutritional Value
The amino acid, fatty acid, and mineral and trace element composition of the
adult insects, their diets, and their excreta were analyzed. The insects were col-
lected when the population was 60 days old; however, one day before collec-
tion, they were starved for 24 hours to eliminate gut content. The specimens
were finely dissected and lyophilized for three days. They were then finely pul-
verized using a ceramic mortar and liquid nitrogen, and again lyophilized until
a constant weight was achieved. The powdered samples were stored at –80°C.
The cricket excreta deposited over a period of one month were collected
from the cardboard containers in the breeding boxes. Most of this waste was
made up of feed and spermatophores. The excrement samples were then dried
at 60°C for 5 days, like the four diets offered during the period of breeding.
Protein Content and Amino Acid Composition
The amino acid pattern of the dietary protein source has a marked influence on
the utilization of feed protein by organisms. The basis of this paradigm is that
the need for protein is explained in terms of a need for individual amino acids,
some of which are indispensable and must be supplied in the diet, the rest re-
quiring only a dietary source of nitrogen and carbon skeletons from which cel-
lular synthesis can occur. Furthermore, it is implicit in this paradigm that the
magnitude of the need for the indispensable amino acids (IAA) is such that dif-
ferent proteins fed at isonitrogenous intakes may vary in ability to satisfy the
520 Ecological Implications of Minilivestock
dietary need for protein. Thus, dietary proteins can be classified in terms of
their quality, a function of their amino acid pattern. The consequence of this
approach is that nutritional adequacy is likely to be met by feed in which the
overall amino acid pattern is optimized by complementation, i.e., balancing in-
adequacies in one protein with abundance in others, to achieve an overall pat-
tern which matches needs. In this respect, traditional feed intake practices that
provide a satisfactory supply of most micronutrients also do the same for di-
etary protein (Milt-Ward et al., 1992).
The “chemical index” (CI) shall mean the lowest of the ratios between the
quantity of each essential amino acid of the test protein and the quantity of each
corresponding amino acid of the reference protein. To calculate CI it is necessary
to analyze the feed protein for its nitrogen content. Protein content is calculated
by multiplying the nitrogen content by 6.25 and the feed protein analyzed to
determine its IAA content. The CI is calculated by dividing the milligrams of a
particular IAA in one gram of the test protein by the milligrams of the indis-
pensable amino acids in one gram of the reference protein which is the amino
acid requirement pattern for a 2- to 5-year-old child. The quality of proteins
refers to the CI, that is, the essential amino acid of the sample and the FAO
pattern ratio (FAO/WHO, 1991).
To determine the chemical index, the protein was first hydrolyzed to yield
individual amino acids and these amino acids then analyzed. Techniques for
determination of amino acids were performed according to methods described
in the literature (Bidlingmeyer et al., 1984; Cohen et al., 1988; Hariharan et al.,
1993; Hirs, 1967; Hugli and Moore, 1972).
Chemical Index =
Essential amino acid content of sample
(mg/g protein)
Pattern FAO amino acid in mg/g
An amino acid with a CI less than 100 is considered falling below the stan-
dard for that amino acid.
Fatty Acid Composition
Fatty acid content was determined according to methods described by Cham-
berlain et al. (1993) and Morrison and Smith (1964), and as specified by Paoletti
et al. (2003).
Trace Element and Mineral Analysis
The insects, diets, excreta, and specimens were dried in a vacuum desiccator
until a constant weight was obtained. Portions (approximately 0.2 g) were
weighed into 125 ml beakers and wet-ashed using 10 ml concentrated nitric acid
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 521
and 1 ml perchloric acid. The samples were covered with watch glasses and
allowed to reflux overnight at 150ºC. The next morning they were taken to near
dryness at 150ºC. Samples that retained a darker color or showed remaining
residue were treated with 1 mL of 4:1 nitric/perchloric acids and redigest. They
were cooled and diluted to 10 mL in 4% nitric acid/1% perchloric acid. Sample
solutions were analyzed for trace metal content by ICP-AES (optical emission
spectrometry with inductively coupled plasma). This digestion technique does
not dissolve any siliceous material in the samples.
Since the calcium content of some samples was out of the analytical range,
some of the specimens had to be diluted and reanalyzed. Even with this second
analysis, however, several samples remained outside the analytical range for
calcium. In some cases the sample supply was depleted so a third dilution and
analysis could not be completed; hence the calcium content was reported as
> 2.5%.
Elements reported as n.d. were below the limit of detection. The limit of
quantitation was 3.33 times the limit of detection.
Under the rearing conditions of 30.5°C and 24 h light, eggs hatched in 13 days
and the adult stage was usually reached in 45 days; thus, the egg-adult cycle
span was about 57 days. It is noteworthy that mortality was greatest during the
first three molts (until day 9–10 at 30°C).
In comparing the average weight gained using the different diets (Fig. 27.1),
it is apparent that the best growth rate was obtained with the human refuse diet.
In one month crickets fed the HRD had doubled in weight and reached maxi-
mum weight (0.45 g per cricket) in 9 weeks. Other diets in order of performance
vis-à-vis growth of the cricket population were DCD + Y (0.43 g per cricket),
DCD (0.40 g per cricket) and AAD for which the mean weight at 10 weeks was
0.35 g per cricket.
In terms of survival, determined on day 61, the following data were ob-
tained: for the colonies fed on ADD survival was 24%, DCD + Y 43.2%, DCD
27.1%, and HRD 47.5% (Fig. 27.2).
With the DCD + Y the optimum period for collecting crickets for consump-
tion was between 9 and 10 weeks; for the HRD, the highest cricket yields were
obtained at 8–9 weeks.
ECI Obtained with Human Refuse Diet
Rearing crickets using the HRD was more efficient with respect to time
and weight gain than were the other diets. For this reason, we decided to
522 Ecological Implications of Minilivestock
Fig. 27.1: Acheta domesticus, average weight gained using different diets (AAD—Aromatic-Arbo-
real Diet; DCD+Y—Dairy Cow Diet with Yeast; HRD—Human Refuse Diet; DCD—Dairy Cow
Fig. 27.2: Acheta domesticus, average mortalities in rearing colonies given different diets (AAD—
Aromatic-Arboreal diet; HRD—Human Refuse Diet; DCD+Y—dairy Cow diet with Yeast; DCD—
Dairy Cow Diet).
1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81
Age in day
weight in grams
22 29
71 78 85 92
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 523
concentrate our efforts in carefully assessing feed input, mortality, and weight
in three colonies raised using the human refuse diet. The three colonies were
each composed of 50 individuals and data collected for 10 weeks, as shown in
Fig. 27.3. From these data we obtained an ECI of 64-65 at week 8 (potentially
best harvesting time) as reported in Table 27.11 (see “Discussion” for more
Protein and Amino Acid Content
Table 27.2 is a summary of the amino acid content of crickets raised under three
different conditions; data for insects raised on the DCD cow diet (without yeast
supplement) are not shown due to lack of exemplars at the time of analysis. Also
included in this Table are the amino acid contents of the excreta and various
diets. Overall, the differences in the contents of the various amino acids in the
crickets were small among the three diets. The limiting amino acid (Table 27.3)
was leucine for those raised on the AAD and leucine and lysine for the HRD. No
essential amino acid was limiting in the case of crickets fed the DCD.
Fatty Acid Content
Table 27.4 summarizes the results of fatty acid analyses (expressed in µg g
sample) of the total lipid fraction of the crickets raised on the three diets. The
fatty acid fractions were rich in polyunsaturated fatty acid with a polyunsatu-
rated/saturated ratio close to the recommended diet intake (stated as 1;
Fig. 27.3: Average density of population, weight, and feed consumption in colonies raised on Hu-
man Refuse Diet.
density of pop.
food consumption
10 17 24 31 38 45 52 59 66
density of pop.
food consumption
524 Ecological Implications of Minilivestock
Table 27.2: Mean amino acid composition of Acheta domesticus (mg g
sample) and SD; AAD, aromatic-arboreal diet, DCD, dairy cow diet and HRD,
human refuse diet
Amino acid A. domesticus A. domesticus A. domesticus Excrement Excrement Excrement Diet Diet Diet
(n=3) (n=3) (n=3) (n=3) (n=3) (n=3) (n=3) (n=3) (n=3)
Asp 71.5 ± 7.3 67.3 ± 7.3 63.1 ± 5.8 5.5 ± 1.3 7.5 ± 3.5 6.2 ± 2.1 20.9 ± 0.4 27.5 ± 1.8 22.3 ± 0.4
Glu 86.5 ± 4.0 86.4 ± 7.1 83.8 ± 1.3 11.4 ± 2.3 12.3 ± 2.8 13.0 ± 2.3 17.3 ± 0.8 43.5 ± 0.6 60.2 ± 0.7
Ser 33.1 ± 2.6 32.0 ± 1.3 29.7 ± 1.0 5.1 ± 0.5 5.8 ± 1.5 6.2 ± 2.4 11.6 ± 0.0 10.6 ± 0.1 12.7 ± 0.1
Gly 27.9 ± 1.6 29.3 ± 1.5 28.4 ± 1.3 12.2 ± 1.6 12.5 ± 4.4 10.1 ± 1.8 8.1 ± 0.1 7.9 ± 0.1 6.7 ± 0.1
His 17.2 ± 0.6 17.4 ± 0.7 16.5 ± 0.5 3.1 ± 0.6 3.5 ± 0.2 3.5 ± 0.7 6.9 ± 0.2 6.4 ± 0.1 7.4 ± 0.1
Arg 41.3 ± 0.7 42.8 ± 1.6 39.6 ± 0.9 5.0 ± 0.6 4.7 ± 2.4 5.5 ± 2.2 13.6 ± 0.00 12.5 ± 0.3 10.5 ± 0.2
Thr 23.4 ± 0.3 24.9 ± 1.2 22.8 ± 2.0 5.2 ± 0.6 4.0 ± 1.2 3.4 ± 0.4 8.6 ± 0.0 8.9 ± 0.1 9.5 ± 0.1
Ala 46.6 ± 2.7 48.0 ± 2.7 45.8 ± 4.9 6.6 ± 0.4 10.3 ± 6.7 9.2 ± 4.0 10.6 ± 0.1 10.9 ± 0.1 9.1 ± 0.2
Pro 33.9 ± 1.2 34.2 ± 1.2 33.0 ± 1.5 6.1 ± 0.5 6.7 ± 2.2 6.9 ± 1.5 11.9 ± 1.0 13.3 ± 0.2 17.9 ± 0.4
Tyr 28.1 ± 3.3 24.9 ± 1.5 22.2 ± 2.3 3.2 ± 0.2 3.6 ± 1.1 3.5 ± 1.8 7.7 ± 0.1 6.9 ± 0.1 8.7 ± 0.6
Val 35.1 ± 0.7 35.6 ± 1.2 33.3 ± 1.8 6.3 ± 0.4 6.6 ± 1.9 6.3 ± 1.7 12.3 ± 0.1 11.6 ± 0.0 12.7 ± 0.2
Ile 24.1 ± 0.3 24.8 ± 1.2 22.3 ± 1.1 4.4 ± 0.3 4.5 ± 2.1 4.3 ± 1.5 8.4 ± 0.1 8.4 ± 0.0 9.3 ± 0.2
Leu 38.2 ± 0.5 39.7 ± 2.1 36.1 ± 1.2 6.5 ± 0.4 6.5 ± 2.7 6.2 ± 1.8 12.3 ± 0.0 15.3 ± 0.0 16.9 ± 0.1
Phe 20.4 ± 0.6 21.8 ± 0.9 20.0 ± 0.4 4.8 ± 0.3 3.8 ± 1.1 3.8 ± 0.7 11.3 ± 0.1 10.9 ± 0.1 11.2 ± 0.1
Lys 33.8 ± 0.9 34.6 ± 1.5 31.8 ± 0.2 6.5 ± 1.1 4.3 ± 1.4 4.8 ± 1.1 12.3 ± 0.1 10.9 ± 0.2 13.9 ± 0.1
Trp 7.1 ± 1.2 7.9 ± 0.8 7.5 ± 0.7 2.3 ± 0.3 1.8 ± 1.2 1.3 ± 0.2 4.3 ± 0.3 3.7 ± 0.4 3.0 ± 0.1
Cys 15.6 ± 2.4 14.0 ± 1.2 12.0 ± 0.9 3.7 ± 1.1 4.7 ± 1.0 3.3 ± 0.4 5.8 ± 0.4 7.2 ± 0.3 4.0 ± 0.1
Met 16.3 ± 1.5 14.0 ± 0.7 13.6 ± 0.4 2.6 ± 0.4 3.3 ± 1.1 2.0 ± 0.2 6.0 ± 0.2 4.5 ± 0.2 6.9 ± 0.0
Sum 600.1 599.0 561.7 100.2 105.7 99.9 189.6 221.0 242.6
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 525
FAO/WHO, 1991). Among the various colonies, the best fatty acid quality was
provided by crickets fed the DCD (Table 27.5). The differences in quantities of
saturated and unsaturated fatty acid present in A. domesticus, rearing diet, and
excreta are reported in Fig. 27.4.
Mineral Content
The results of mineral analysis are shown in Table 27.6. Calcium content of crickets
is higher than conventional food such as salmon, pig, or beef. The
calcium:phosphorus ratio of the crickets fed the dairy cow diet was 1.0:4.4, the
human refuse diet 1.0:6.4, and the aromatic-arboreal diet 1.0:1.54. The iron content
of crickets was relatively high, especially in colonies reared on the DCD, with
values similar to those for beef; Table 27.6 reports a higher iron content for frogs.
Table 27.3: Chemical index of proteins in AAD, DCD, and HRD
A. domesticus A. domesticus A. domesticus
His 151 153 155
Ile 143 148 142
Leu 96 100 97
Lys 97 100 97
Cys+Met 213 187 182
Phe+Tyr 128 124 119
Thr 114 122 119
Trp 107 114 127
Val 167 170 169
Fig. 27.4: Percent of saturated and unsaturated portions of fatty acid in samples.
(Legends Fig. 27.1)
Diet AAD
A. domesticus AAD
Excrement AAD
Diet DCD
A. domesticus DCD
Excrement DCD
Diet HRD
A. domesticus HRD
Excrement HRD
Diet AAD
A. domesticus AAD
Excrement AAD
Diet AAD
A. domesticus AAD
Excrement AAD
Diet AAD
A. domesticus AAD
Excrement AAD
526 Ecological Implications of Minilivestock
Table 27.4: Mean composition of fatty acid in Acheta domesticus, in collected excrement, and in diet offered—with SD. Values reported as µg g
of dry
Fatty acid A. A. A. Excrement Excrement Excrement Diet Diet Diet
domesticus domesticus domesticus AAD DCD HRD AAD DCD HRD
AAD DCD HRD (n=3) (n=3) (n=3) (n=1) (n=1) (n=1)
(n=3) (n=3) (n=3)
C12:0 Lauric acid 0.26 0.08 0.16 ± 0.00 ND ND 0.06 ± 0.04 N.D 0.01 1.02
C14:0 Myristic acid 0.45 ± 0.07 0.58 ± 0.16 2.96 ± 1.45 0.17 ± 0.09 0.04 ± 0.02 1.12 ± 0.14 0.15 0.05 5.31
C15:0 Pentadecanoic acid 0.22 ± 0.06 0.15 ± 0.02 0.46 ± 0.21 0.04 ± 0.02 0.02 ± 0.01 0.15 ± 0.01 0.024 0.02 0.58
C16:0 Palmitic acid 21.18 ± 3.88 22.07 ± 3.92 31.82 ± 10.73 1.21 ± 0.35 0.68 ± 0.08 5.13 ± 0.54 1.84 6.02 23.26
C18:0 Stearic acid 6.05 ± 0.71 8.04 ± 1.43 8.87 ± 2.26 0.39 ± 0.13 0.25 ± 0.02 1.64 ± 0.17 0.30 1.59 6.20
C20:0 Eicosanoic acid 0.19 ± 0.04 0.27 ± 0.01 0.23 ± 0.06 0.06 ± 0.02 0.02 ± 0.00 0.06 ± 0.00 0.05 0.12 0.18
C22:0 Behenic acid 0.04 0.07 ± 0.04 0.06 ± 0.04 0.05 ± 0.01 0.02 ± 0.00 0.02 ± 0.01 0.03 0.10 0.07
C24:0 Lignoceric acid ND ND ND 0.03 ± 0.01 0.01 ± 0.00 ND N.D 0.03 ND
Subtotal 28.39 31.27 44.56 1.95 1.042 8.18 2.40 7.94 36.62
C14:1 Myristoleic acid 0.03 ± 0.01 0.05 ± 0.01 0.18 ± 0.12 0.02 ± 0.01 0.01 ± 0.00 0.05 ± 0.01 0.01 0.02 0.39
C16:1 Palmitoleic acid 3.93 ± 1.05 0.63 ± 0.14 2.22 ± 0.79 0.72 ± 0.28 0.11 ± 0.07 0.21 ± 0.06 0.24 0.18 1.48
ω9 Oleic acid 16.62 ± 2.80 18.96 ± 1.94 29.56 ± 10.16 1.46 ± 0.52 1.15 ± 0.16 3.00 ± 1.07 1.14 9.32 27.33
ω7 Vaccenoic acid 0.47 ± 0.12 1.01 ± 0.14 1.50 ± 0.60 0.15 ± 0.05 0.23 ± 0.05 0.37 ± 0.06 0.12 0.55 1.58
ω9 D11-Eicosenoic acid 0.09 ± 0.00 0.11 ± 0.02 0.18 ± 0.02 0.06 ± 0.04 0.03 ± 0.01 0.44 ± 0.06 0.02 0.07 0.18
ω7 D13-Eicosenoic acid 0.04 ± 0.01 0.05 ± 0.01 0.11 ± 0.05 0.02 ± 0.01 0.01 ± 0.00 0.04 ± 0.02 0.02 0.01 0.02
ω9 Euric acid 0.05 ± 0.03 0.11 ± 0.01 0.08 ± 0.01 0.07 ± 0.02 0.06 ± 0.04 0.05 ± 0.01 0.12 0.03 0.02
C24:1 Nervonic acid 0.17 0.12 ± 0.08 0.05 ± 0.02 0.04 ± 0.02 0.02 ± 0.01 0.02 ± 0.01 N.D ND ND
Subtotal 21.39 21.03 33.87 2.54 1.62 4.18 1.65 10.19 31.00
ω6 Linoleic acid 18.97 ± 2.74 39.11 ± 3.09 20.15 ± 2.92 0.40 ± 0.13 0.98 ± 0.06 0.60 ± 0.26 0.93 21.50 5.87
ω6 γ-Linolenic acid 0.03 ± 0.00 ND 0.05 ± 0.01 ND ND ND 0.01 ND 0.03
ω3 α-Linolenic acid 3.71 ± 0.71 2.91 ± 0.31 1.39 ± 0.69 0.75 ± 0.28 0.13 ± 0.01 0.09 ± 0.02 3.46 3.13 0.88
Table 27.4: (Contd.)
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 527
Table 27.5: Saturated and unsaturated fractions of fatty acid in Acheta domesticus, excrement, and diets (in %)
Acheta domesticus Excrement Diets
Saturated 39.1 33.0 43.9 34.6 27.4 63.0 28.3 18.6 49.0
Monounsaturated 29.4 22.2 33.2 44.7 42.8 31.5 19.5 23.8 41.5
Polyunsaturated 31.5 44.8 22.9 20.7 29.8 5.5 52.2 57.6 9.5
Pol./Sat. ratio 0.81 1.36 0.52 0.60 1.09 0.09 1.84 3.10 0.19
Table 27.4: (Contd.)
Fatty acid A. A. A. Excrement Excrement Excrement Diet Diet Diet
domesticus domesticus domesticus AAD DCD HRD AAD DCD HRD
AAD DCD HRD (n=3) (n=3) (n=3) (n=1) (n=1) (n=1)
(n=3) (n=3) (n=3)
ω6 D11,14-eicosadienoic acid 0.05 ± 0.03 0.05 ± 0.01 0.10 ± 0.03 0.01 ± 0.01 0.01 ± 0.00 0.02 ± 0.01 0.01 0.02 0.08
ω6 Dihomo-g-linolenic acid ND ND 0.06 ± 0.02 ND ND 0.01 ± 0.00 N.D ND 0.06
C20:4w6 Arachidonic acid ND 0.09 0.33 ± 0.05 ND 0.01 ± 0.00 0.02 ± 0.01 N.D ND 0.16
ω3 Timnodonic acid ND ND 0.13 ± 0.06 0.02 ± 0.01 0.01 0.01 N.D ND 0.02
ω6 Adrenic acid ND ND ND ND ND ND N.D ND 0.02
ω6 D4,7,10,13,16- ND ND ND ND ND ND N.D ND ND
docosapentaenoic acid
ω3 D7,10,13,16,19- ND ND ND ND ND ND N.D ND 0.03
docosapentaenoic acid
ω3 Clupanodonic acid ND ND ND ND ND ND N.D ND ND
Subtotal 22.76 42.15 22.21 ± 3.77 1.17 1.13 0.75 4.42 24.65 7.13
Total fatty acid 72.23 94.29 100.53 5.66 3.79 13.10 8.47 42.78 74.75
ND: Absence of values means they were not detectable by analysis.
528 Ecological Implications of Minilivestock
Table 27.6: Mineral content in A. domesticus and other food; AAD, aromatic-arboreal diet, DCD, dairy cow diet and HRD, human refuse diet, results
reported as µg/gram of element per sample
Ag n.d. n.d. n.d.
Al 9.86 12.58 10.72
As 0.01 0.08 0.07
Ba 0.37 0.56 0.27
Be 0.02 0.02 0.01
Ca 480 366 384 407 275 270 380 330 880 200 50 80 40 40 150 300 240 120
Cd 0.01 0.02 0.04
Co 0.02 0.02 0.01
Cr 0.68 1.02 0.68
Cu 9.2 8.7 8.5 6.2 5.1 7 2 12 0.9 1.3 2 0.8 3.1 4 1.8
Fe 19.5 26.7 16.2 19.3 21.2 7 12 18 58 60 6 8 39 19 24 36 8 10
K 2,812 2,589 2,642 3,470 3,520 3,100 3,600 6,300 3,200 3,000 2,900 3,310 3,300 2,870 4,940 920 200
La 0.06 0.04 n.d.
Li 0.02 0.04 0.01
Mg 306 267 255 337 226 210 100 440 240 170 290 200 1200 1600 200
Mn 6.1 8.0 4.6 11.5 8.9
Mo 0.21 0.40 0.17
Na 2,045 2,376 2,474 1,340 1,350 980 1,300 660 2,900 620 560 740 410 350 50 40
Ni 0.16 0.32 0.13
P 2,605 1,607 2,442 2,950 2,520 2,800 2,640 2,150 2,360 4,300 1,600 1,600 2,310 2,000 2,560 3,300 940 120
Pb 0.20 0.06 0.08
Sb 0.83 n.d. n.d.
A. domesticus AAD
A. domesticus DCD
A. domesticus HRD
A. domesticus (adult)
A. domesticus (nymph)
Salmon (Salmo salar
Mackerel (Scomber
Sardines (Sardina
Mussel (Mytilus edulis
Frog (Rana esculenta
Chicken (Gallus gallus
Pig (Sus scrofa
domestica)², beef
Horse (Equus cabalus
Adult bovine (Bos
taurus)², filet
Corn (Zea mays
Wheat (Triticum durum
Rice (Oryza sativa
Tapioca (Manihot
Table 27.6: (Contd.)
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 529
Se n.d. n.d. n.d. 0.19 0.1
Sr 1.25 0.71 0.80
Te n.d. 0.11 n.d.
Ti 0.10 0.14 0.09
Tl 0.16 n.d. 0.21
V 0.01 0.01 0.01
Y 0.01 0.01 0.01 0.21 0.28
Zn 61.4 52.7 65.8 67.1 68.0 20 8 22 10.8 16 37.2 28 22.1 29 13
Zr 0.06 0.04 0.06
Finke, 2002. Values for commercially raised crickets. Data are expressed on an is basis.
²Carnovale E. and Marletta L. 2000. Composizione degli alimenti. Istituto Nazionale di Ricerca per gli alimenti e la nutrizione.
n.d. = non detectable
— = not reported
Table 27.6: (Contd.)
530 Ecological Implications of Minilivestock
The high sodium content probably reflects NaCl supplementation of the diets.
Silver (Ag), antimony (Sb), selenium (Se), and tellurium (Te) were not detectable.
From the standpoint of weight gain and survivorship, the best diets with which
to rear crickets appeared to be dairy cow supplemented with yeast, followed
closely by the human refuse diet. The poorest insect yield was obtained using
the aromatic-arboreal diet, attributable largely to the fact that many of the crick-
ets were cannibalized. Apparently the aromatic-arboreal diet was not well-bal-
anced nutritionally and hence the stronger crickets supplemented their alimen-
tation by consuming the weaker ones.
Since magnesium is known to reduce the activity of crustaceans (Morris
and Spicer, 1993) and because it has a narcotic effect that reduces aggression in
molted exemplars (Chouduri and Bagh, 1974), in an effort to reduce cannibal-
ism we added magnesium chloride to the insect drinking water: surprisingly,
magnesium had no effect either on the extent of cannibalism or the insect sing-
ing performances.
From the data gathered, it appears that the best time to collect crickets for
consumption is before they become full adults, that is, at about week 4 or week
5 (Fig. 27.1). Adults, compared with nymphs, have a more coriaceous exoskel-
eton and develop wings. From the standpoint of weight gain, the optimum har-
vesting time was between week 8 and 9.
Cricket exoskeleton is partiallly composed of chitin, a biopolymer that cannot
be hydrolyzed by humans lacking the appropriate enzymes. Thus chitin acts
like dietary fiber without offering any calories. So, whole insects as a source of
protein are of somewhat lower quality than vertebrate animal products because
of the indigestibility of chitin (Phelps et al., 1975; Dreyer and Wehmeyer, 1982).
Chitinase, an enzyme that digests chitin, is found in fish (Rehbein et al.,
1986), reptiles, birds (Weiser et al., 1997) insectivorous mammals (Smith et al.,
1998) and cetaceans (Olsen et al., 2000), animals that feed on insects, and crusta-
ceans including krill. Chitinase is also present in association with other enzymes
such as papain and bromelain in some tropical plants, e.g. pineapple (Ananas
comosus), mango (Mangifera indica), and pawpaw (Carica papaya) (Azarkanb et
al., 1987; Subroto et al., 1999) where it seems to perform antimycotic activities.
Apparently in carnivorous Bromeliaceae, most of the enzymes used to release
nutrients contained in animal and vegetal tissues are not secreted directly by the
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 531
plants but produced by the bacteria and saprophytic fungi hosted by them
(Benzing, 1980). Papain and bromelain assist in protein degradation by releas-
ing free amino acids that are ready for absorption and enabling optimization of
fat assimilation.
It would be interesting to study whether consumption of insects combined
with the tropical fruits cited above or other material would lead to chitin soften-
ing or even digestion. According to Goodman (1989), insect chitin has antican-
cer properties. Various studies (Muzzarelli, 1997) report on the successful use of
chitin and derivates in ulcer and lipid absorption.
Results of the present study indicate that in terms of weight gain and mortality,
the best diet for rearing crickets is the HRD (Fig. 27.2). This indicates that its
nutrient content and balance are superior to those of the other diets.
The great difference in yield of crickets obtained for the two dairy cow diets
led us to speculate that the yeast supplement probably provides the insects with
critical growth factors. The nutritional value of yeast for the growth of insects
has been documented by McFarlane and coworkers (1959) and Patton (1967).
Amino Acid Composition
Except for aspartic acid and tyrosine, both of which are nonessential amino acids,
there were few differences in the amounts of the various amino acids contained
in the crickets raised on the three diets (Table 27.2). With the exception of glutamic
acid, the foods offered to the insects did not vary greatly in their content of the
various amino acids. The Chemical Index (Table 27.3) of each of the three diets
was close to 100 in all samples, thereby indicating these foods contained good-
quality proteins.
Fatty Acid Composition
The amount of fatty acid in the three colonies of crickets was relatively high and
ranged from 6 to 12% dry weight. Good quantities of the two essential fatty
acids, linoleic acid (18:2ω-6) and α-linolenic (18:3ω-3) were present: linoleic acid
at a percentage of 26.24 ± 0.71 in AAD, 41.50 ± 1.30% in DCD, and 20.84 ± 4.09%
in HRD, α-linolenic acid at a percentage of 5.13 ± 0.71 in AAD; 3.08 ± 0.17% in
DCD, and 1.31 ± 0.36% in HRD. These fatty acids represent the substrates for
the synthesis of longer, more unsaturated fatty acids. Usually the major dietary
sources of linoleic acid and α-linolenic acid are polyunsaturated fatty acid-rich
vegetable oils. Recommended dietary intakes of linoleic acid and α-linolenic
532 Ecological Implications of Minilivestock
acid are usually about 3–5% and 0.5% of dietary energy respectively (Ziegler
and Filer, 1996).
Interestingly, arachidonic acid was either absent or present at very low lev-
els in all the cricket specimens, regardless of the food upon which they were
raised. Also absent or lacking were the long-chain polyunsaturated fatty acids,
eicosapentaenoic acid and docosahexaenoic acid in particular. The excreta con-
tained very little fatty acid, indicating that crickets do an efficient job of digest-
ing and absorbing the lipids in their diets.
The polyunsaturated/saturated ratio in the HRD is not close to unit, prob-
ably because the quantities of fat varied in the meat leftovers used in preparing
the diet. This value is confirmed from the high amount of lipid found in the
excreta. Simply reducing the quantity of animal fat in the leftovers used as in-
gredients in preparing the diets should diminish this value.
Minerals and Trace Elements
As mentioned earlier, Table 27.6 compares the mineral and trace element com-
position of A. domesticus with that of some common foods. The quantities of
calcium, copper, and magnesium in the crickets exceeded those of other animals
except mussel. The potassium content of the crickets was slightly lower than in
fish, mollusks, amphibians and other vertebrates. The phosphorus content var-
ied greatly among the crickets grown on the three diets; in general, however, the
crickets contained more phosphorus than some common livestock consumed
by humans. The zinc content of crickets was high and comparable to that re-
ported for other common animal and plant foods (Table 27.6). The relatively
high sodium content of the crickets was likely the result of supplementation of
the diets with sodium chloride, as suggested by other investigators (Nakagaki
et al., 1987; Luckey and Stone, 1968).
ECI Obtained Using the Human Refuse Diet
Total body composition data (Table 27.7) show that crickets have a higher water
content, similar protein content, and significantly less fat than most common
livestock. The ECI for the diets in our trials was much higher than for any of the
vertebrate species, i.e., poultry 1.5 times higher, pig and sheep 2 times higher
and beef 4 times higher. The differences between our results and those of
Nakagaki and DeFoliart (1991) are probably due to differences in insect harvest-
ing times; they harvested at 21 days, we harvested at 45 days.
The favorable conversion efficiency showed by crickets relative to domesti-
cated animals, and by insects in general, is probably due to their unusual physi-
ology; insects do not have to spend energy maintaining body temperature. An-
other advantage of insect breeding is the short span of productive cycle. These
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 533
points should to be taken into consideration in the context of commercial
Environmental Impacts and Diet Sustainability
In breeding crickets using the dairy cow diet, we were able to identify possible
environmental factors related to: tillage (soil erosion, organic soil loss), chemical
fertilizers, insecticides, herbicides and fungicides applications and their poten-
tial effects on nontarget organisms and the environment.
Table 27.8 reports such impacts under conditions of conventional cultiva-
tion. We tried to measure the possible environmental impacts of various crops
under conventional agricultural practices. Activities such as tillage, use of chemi-
cal fertilizers, insecticide, herbicide, and fungicide applications were “weighed”
on the basis of assessed agronomic practices: the “weight” of every activity, ex-
pressed on a scale of 1 to 4 (where 1 represent lowest impact) was summed to
obtain an index of total impact. In this manner we were able to recognize that in
Table 27.7: Comparison of current breeding animals and Acheta domesticus (in vertebrates, entrails
are not included) and ECI
Species and references % Water % Protein % Fat % ECI
A. domesticus
Woodring et al. 1977 68.4 15.0 10.3
Nakagaki and DeFoliart, 1991 74.2 92
Finke, 2002 ¹ 73.1 17.9 5.1
This work² 72.3 16.3 59
Ensminger, 1980 64.0 18.8 14.2
Meyer and Nelson, 1963 28.6 4.9 35
Lovell, 1979 48
Ensminger, 1980 50.0 13.0 34.4
Meyer and Nelson, 1963 12.7 38.0 28
Whittemore & Elsey, 1976 52.6 14.7 29.5
Lovell, 1979 31
Ensminger, 1980 53.2 15 29.0
Meyer & Nelson, 1963 15.2 25.2 18
Ensminger, 1980 53.5 17.0 26.0
Meyer and Nelson, 1963 18.2 21.1 16
Berg and Butterfield, 1976 52.0 17.1 26.9
Lovell, 1979 13
¹ Average values of adults and young.
² Colonies fed with human refuse diet.
534 Ecological Implications of Minilivestock
Table 27.8: Environmental impacts of different crops under conventional agricultural practices
Tillage Chemical Fungicides Insecticides Herbicides Total
fertilizers impact
Corn flour (Zea mays) xxx xxxx x xxxx 12
Silage corn (Zea mays) xxx xxx x xxx 10
Soybean flour
(Glycine max) xx x xxx 6
(Medicago sativa) x x x 3
Sugar beet (Beta
vulgaris var. esculenta) xxx xxx xx xx xxxx 14
Wheat (Triticum durum) xx xx x x 6
Table 27.9: Annual production of different crops per hectare (ha); 1 q = 100 kg (pers. comm. Prof. G.
Cozzi, 2002)
Lucern (Medicago sativa), hay 13 q/ha;
Corn flour (Zea mays) 120 q/ha;
Silage corn (Zea mays) 800 q/ha;
Soybean flour (Glycine max) 40 q/ha;
Wheat (Triticum durum) 70 q/ha;
Sugar beet (Beta vulgaris var. esculenta) 650 q/ha.
Table 27.10: Resources and cultivable surface needed to produce 1 ton of Acheta domesticus with
dairy cow diet (DCD)
Soybean Lucern Corn Wheat Sugar Silage Total
flour beet corn
Resources needed 6.4 q 5.5 q 4.6 q 4.1 q 3.6 q 3.5 q 27.8 q
Surface needed 1596 m² 425 m² 382 m² 593 m² 56 m² 44 m² 3096 m²
cultivating sugar beet or corn greater impacting activities are involved than in
cultivating alfalfa.
Most of the ingredients used in the diets tested in this work have a low
impact on conventional methods of production and might have an even lower
impact were biological or integrated agriculture were the goal.
An estimate of the resources required to produce 1 ton of A. domesticus us-
ing conventional agriculture is reported in Table 27.9. As for of the yeast-based
diet, we were not able to estimate the environmental cost of cricket production
due to lack of information about yeast production and impacts.
Based on diet consumption, we estimated that 2.78 tons were required to
produce one ton of crickets. The quantities of the various dietary components
and cultivable surface needed to produce one ton of crickets are shown in Table
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 535
Hygienic Hazard and Potential Constraints
The vernacular and scientific names of Acheta domesticus suggest infestation of
human dwellings and in the past they were common inhabitants of kitchens,
bakeries, and places where grains and flour were stored; in recent years they
have become rare if not altogether absent, depending largely on the standards
of hygiene acquired by humans. Moreover, insects can be vectors of disease,
spreading various forms of parasite and pathogen: virus, rickettsiae, bacteria,
protozoa, and nematodes (Busvine, 1980).
In this study neither viral and bacteriological susceptibilities of bred A.
domesticus, nor their potential allergenic properties were assessed. Insects, as
arthropods, could present the same problems as shellfish (i.e., shrimp, lobster,
crayfish), which are well known for their ability to induce mild to severe allergic
reactions in susceptible individuals. Thus, this risk should not be taken lightly.
Usually the popular image of insect allergies is that associated with the bites
and stings of venomous species such as bees, ants, and wasps (injectant aller-
gens). More common allergic reactions attributable to insects include those caused
by contacting body parts or waste products (contact allergens) or inhaling mi-
croscopic dust particles composed of pulverized carcasses, cast skins and ex-
creta (inhalant allergens). Allergies caused by contacting or inhaling insect ma-
terial can have significant health consequences in the home or work environ-
ment with symptoms ranging from eczema and dermatitis, to rhinitis, conges-
tion, and bronchial asthma. In severe cases, sensitivity to insect material might
be heightened to the extent that the victim experiences anaphylactic shock, a
potentially life-threatening condition often involving rapid swelling, acute res-
piratory distress, and collapse of circulation (Phillips and Burkholder, 1984).
Since most insect allergies are of the contact and inhalant type, it would be rea-
sonable to assume that the greatest health risk associated with food insects would
be to workers involved in their production. Given the small and obscure nature
of the food insects industry, virtually nothing is known of such problems. A case
has been reported for Bulgaria in which employees working on nuts acquired
eczema and dermatitis due to contact with substances secreted by larvae of Plodia
interpunctella feeding on the nuts (Phillips and Burkholder, 1995).
Reactions to Orthoptera (grasshoppers, crickets, locusts, cockroaches, etc.)
are also common. LeClercq (1969) reported that workers rearing locusts suf-
fered rhinitis, itching skin, bronchitis, and ultimately asthma in general sequence.
Wirtz (1980) recounted one study of migratory locusts where all of the workers
became allergic to the insect. We know of a researcher who suffered dyspnea
(labored breathing) during a prolonged session of grinding crickets into meal to
supplement chicken feed. Three cases of anaphylactic shock involving orthop-
terans were reported by Wirtz. Good ventilation, protective clothing, gloves,
and masks are common sense preventive measures.
Our major interest focused on ingestant allergens, that is, eating or uninten-
tionally swallowing allergenic insect material. Unfortunately direct evidence
536 Ecological Implications of Minilivestock
for allergies to food insects is practically nonexistent. Some insight can be gained
from controlled experiments on human subjects done with preparations of com-
mon food-infesting insects. A classic study by Bernton and Brown in 1967 uti-
lized dialized extracts of seven such insects in skin sensitivity tests of subjects
with and without known allergies. Test extracts included those of the rice wee-
vil (Sitophilus oryzae), fruit fly (Drosophila melanogaster), Indian meal moth (Plodia
interpunctella), saw-toothed grain beetle (Oryzaephilus surinamensis), red flour
beetle larvae and adults (Tribolium castaneum), flour beetle (Tribolium confusum),
and lesser grain borer (Rhyzopertha dominica). Of the 230 allergic patients, 68
(29.6%) reacted positively to one or more of the dialized insect extracts. Surpris-
ingly, of the 194 nonallergic subjects, 50 (25.8%) showed sensitivity to at least
one extract. A total of 333 positive reactions were observed. The degree of over-
all sensitivity was practically the same for both groups, with the Indian meal
moth extract eliciting the most positive reactions followed by extracts of red
flour beetle larvae, red flour beetle adults, rice weevils, fruit flies, confused flour
beetles, saw-toothed grain beetles, and lesser grain borers.
The only reported case of A. domesticus as a vector of diseases in vertebrates
is mentioned for Geopetitia aspiculata, a nematode found in 12 species of
Passeriformes, one species of Charadriiformes and one species of Coraciiformes
which died at the Assiniboine Park Zoo, Winnipeg, Canada. Fortunately, this
nematode is harmless for humans (Bartlett et al., 1984).
There may be processes that can effectively diminish the potential threat of
food allergies. One school of thought suggests that insect allergens in food are
deactivated by cooking, yet when five of the aforementioned insect extracts were
heated at 100°C for one hour, positive skin reactions were still observed, albeit
deemed less vigorous than those of the unheated treatments. In a 1964 study,
Bernton and Brown heat-treated extracts of cockroaches at 100°C for one hour
and found that these allergens resisted deactivation. The idea that insect aller-
gens are deactivated in the highly acidic environment of the stomach is also
appealing until one considers the number of normally eaten foods that have
been identified as potentially allergenic and whose allergens obviously survive
digestion and cooking.
For most people, working with or eating food insects should pose little if
any health risk, especially if they have no history of allergy to insects or other
arthropods. Nonetheless, since sensitivity can be acquired with repeated expo-
sure to an allergen, a measure of vigilance is in order. A person with known
insect or arthropod allergies would be wise to exercise some caution. Cross-
reactivity among related as well as taxonomically dispersed groups of insects
has been established. There is also evidence for cross-reactivity among distantly
related members of Arthropoda, suggesting the existence of common allergens
within the phylum. So, if you are allergic to shellfish, you might want to recon-
sider the idea of eating insects.
Alberto Collavo, Robert H. Glew, Yung-Sheng Huang et al. 537
Crickets are a good resource of animal protein, fat, and other nutrients.
Some considerations about costs should be made in cricket breeding. When
a human refuse diet is adopted, the input starts at a level of domestic waste. If
not used, this material represents a cost for waste processing and disposal and a
loss of organic matter. Otherwise, by converting this organic refuse into animal
proteins, the waste becomes a resource (Table 27.11).
Table 27.11: Mean density of population (and SD), fresh weight of A. domesticus, diet consumed,
and Efficiency Conversion Index (ECI) in colonies fed human refuse diet (HRD)
Days of life Density of Weight of Amount of diet ECI
population A. domesticus consumed (in g)
(no. of crickets) (in g)
10 50 ± 0 0.010 ± 0.001
17 48 ± 2 0.019 ± 0.009
24 47 ± 2 0.125 ± 0.013
31 44 ± 1 0.236 ± 0.011
38 43 ± 2 0.266 ± 0.038 0.426 ± 0.039 63 ± 6.11
45 41 ± 3 0.358 ± 0.041 0.605 ± 0.036 59 ± 4.16
52 41 ± 3 0.422 ± 0.026 0.663 ± 0.027 64 ± 2.52
59 36 ± 2 0.451 ± 0.017 0.694 ± 0.022 65 ± 1.73
66 34 ± 3 0.452 ± 0.016 0.721 ± 0.027 63 ± 2.08
Where the dairy cow diet is used, one needs to consider in the production
system costs for agricultural ingredients composing the diet and the relative
costs of herbicides, fungicides, insecticides, and fertilizers causing high envi-
ronmental impacts and potential hazards.
The aromatic arboreal diet does not seem favorable for the low cricket popu-
lation density it can sustain; however it appears environmentally more friendly.
The protein quality and linoleic and a-linolenic acid content of crickets are
high. The fatty acid profiles most likely reflect the fatty acid composition of the
feed, which is commonly seen in monogastric animals (Finke, 2002).
The chitin in crickets presents a problem because of its nondigestibility in
humans, as well other livestock, due to their lack of chitinase. Future studies
should investigate whether this problem can be solved by consuming insects
together with fruits such as Bromeliaceae and Caricaceae that contain enzymes
with an activity similar to chitinase. To reduce the quantity of chitin, insect har-
vesting could be done before the last molt.
Excreta produced during the breeding cycle, still high in nitrogen, can be
used as fertilizer or input for crops.
To purchase crickets, contact: Livefood UK:
538 Ecological Implications of Minilivestock
Azarkanb M., Amranib A., Nijsb M., Vandermeersa A. et al. 1997. Carica papaya latex is a rich
source of a class II chitinase. Phytochem. 46: 1319–1325.
Bartlett C.M., Crawshaw G.J., and Appy R.G. 1984. Epizootiology, development, and pathology of
Geopetitia aspiculata Webster, 1971 (Nematoda: Habronematoidea) in tropical birds at the
Assiniboine Park Zoo, Winnipeg. Canada J. Wildl. Dis. 20: 289–99.
Benzing D.H. 1980. The Biology of Bromeliads. Mad River Press, Eureka, CA, USA, 305 pp.
Bernton H.S. and Brown H. 1964. Insect allergy—preliminary studies of the cockroach. J. Allergy
35: 506–513.
Bernton H.S. and Brown H. 1967. Insects as potential sources of ingestant allergens. Ann. Allergy
25: 381–387.
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... In addition to environmental aspects, edible insects have major nutritional benefits, as they contain all the nutrients required in a healthy diet, including high levels of good quality proteins and lipids (Feng et al., 2018;Gahukar, 2013;Rumpold and Schlüter, 2013). (Oonincx and de Boer, 2012); Water use: l/g protein (Miglietta et al., 2015); Feed conversion ratio: kg of feed/kg liveweight gain (Collavo et al., 2005;van Huis, 2013;Oonincx and de Boer, 2012); Global warming potential: kg of C02 eq/kg edible protein (Oonincx and de Boer, 2012;de Vries and de Boer, 2010); Energy use: mega joules/kg of edible protein (Oonincx and de Boer, 2012). ...
Entomophagy is well established in the food habits of Africa; however, country-wide knowledge remains limited for several countries, including Gabon. Here, two surveys on entomophagy were conducted in Gabon through face-to-face interviews. The first survey collected information on insect eating habits from 169 potential consumers. Edible insects formed part of the diet of most Gabonese people, with more than 60% of consumers within participants, and were particularly common among the Teke ethnic group (93%). Familiarity with edible insects was influenced by culture and family, but not by gender or study level. The second survey focused on edible insect species and their host plants, by interviewing a sample of 113 both villagers and retailers. Seventy-five species of insects from six insect orders (Coleoptera, Hemiptera, Isoptera, Lepidoptera, Odonata and Orthoptera) were consumed in Gabon, and were collected from 48 species of host plant. Many insects were formerly reported in the literature related to entomophagy; however, 13 species were newly reported as edible in this study: Bidessus batekensis, Bunaeopsis licharbas, Copelatus ateles, Copelatus confinis, Copelatus fizpaci, Copelatus tondangoyei, Gonobombyx angulata, Gonometa titan, Hydrocyrius columbiae, Oxychirus semisericeus, Philobota sp., Psara sp. and Ptyelus flavescens. Consequently, these surveys highlighted that entomophagy is common in Gabon. However, strategies to promote edible insects are needed to have a significant impact on food issues in Gabon (e.g. food insecurity and dependence on foreign food supplies). Additional researches on entomophagy in Gabon are required to further develop these strategies.
... Insects grow and reproduce easily; being cold-blooded, they have high feed conversion efficiency. On average, 1 kg of insect biomass can be produced from 2 kg of feed biomass (Collavo et al. 2005). According to the Commission Regulation (EC) 1069/2009, insect farming is considered as livestock farming. ...
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The aim of this study was to evaluate the effect of Tenebrio molitor larvae meal supplementation in chicken diets on the chemical composition and sensory quality of meat. The experiment was conducted on 120 Ross 308 male broilers from day 12 to day 38 of their age. Broilers were divided into three equal groups with 5 replicates per treatment. The two experimental groups received feed mixtures containing 2% (TM2; n = 40) and 5% (TM5; n = 40), respectively of yellow mealworm (Tenebrio molitor L.) meal. The third group (TM0; n = 40) was control, receiving 0% of mealworms in diet. The addition of mealworm meal to diets in this trial do not worsen the chemical composition or sensory characteristics of the thigh meat of broilers. The control chickens had a higher live weight (P < 0.05) compared to the experimental groups at the end of the trial. The lowest live weight and feed intake was determined in group TM2 (P < 0.05). The highest feed intake (P < 0.05) was found in the control group. The breast meat from the control group was rated better (P < 0.05) in flavour compared to the groups receiving 2% and 5% of yellow mealworms. The primary requirement for the use of any ingredient in feed is that it does not adversely affect food safety and quality. In our study, the inclusion of 2% and 5% mealworm meal in the broiler's diet had no influence on meat quality.
... Because insects are cold-blooded, they have a high food conversion rate, e.g., crickets need sixfold less feed than cattle, fourfold less than sheep, and half as much as pigs and broiler chickens to produce the same amount of protein. Crickets, for example, require only 1.7-2 kg of feed for every 1 kg of body weight gain (Collavo et al., 2005). For comparison, to gain 1 kg of body weight, a chicken must consume 2.5 kg feed, a pig 5.5 kg, and cattle 10 kg (Kupferschmidt, 2015). ...
During the last decade, gluten-free food consumption has become a widespread diet trend due to the awareness of gluten intolerances/allergies, as better diagnostic tools are becoming available, and because of the increased number of consumers following this diet regardless of medical needs. However, production of gluten-free foods comprises technological challenges that have to be addressed. The chapter is initially introducing the concept of gluten-free food production in accordance to current gluten-free product markets and labeling regulations worldwide. The need to improve the quality of gluten-free products highlighting both nutritional and formulations aspects is also examined. In this context, it provides a comprehensive overview of various techniques applied in the production of gluten-free foods for combating the commonly encountered problems related to the elimination of gluten. These techniques include compositional approaches, such as the addition of different ingredients and additives in gluten-free formulations. Additionally, bioprocessing fermentations, novel optimal processing technologies, and transgenic methodologies are discussed as the main emerging technological approaches for affecting physico-chemical, sensory, and nutritional characteristics of gluten-free foods.
... Because insects are cold-blooded, they have a high food conversion rate, e.g., crickets need sixfold less feed than cattle, fourfold less than sheep, and half as much as pigs and broiler chickens to produce the same amount of protein. Crickets, for example, require only 1.7-2 kg of feed for every 1 kg of body weight gain (Collavo et al., 2005). For comparison, to gain 1 kg of body weight, a chicken must consume 2.5 kg feed, a pig 5.5 kg, and cattle 10 kg (Kupferschmidt, 2015). ...
... Many edible species have been touted as a good source of bioavailable protein (Verkerk et al. 2007) with crude levels comparable to and in some cases even higher than other animal protein sources (Melo et al. 2011;Belluco et al. 2013). Numerous species contain all essential amino acids for human nutrition (Bukkens 2005;Collavo et al. 2005), and many are thought to supply important nutrients, including specific amino acids, which are deficient in cereal-and legume-based diets (van Huis et al. 2013;Nadeau et al. 2015;Manditsera et al. 2019). Insects can serve as an important protein supplement to the diet, but it should be noted that not all insects are created equalsome are low in specific essential amino acids (Williams et al. 2016). ...
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Global communities increasingly struggle to provide ample healthful food for growing populations in the face of social and environmental pressures. Insect agriculture is one underexplored and innovative approach. Sustainable cultivation of nutrient-dense edible insects could help boost food access, support human nutrition, and mitigate key drivers of climate change. The edible insects industry is in its nascent stages, as relatively few entities have committed resources towards optimizing farming methods. Nevertheless, insect farming is poised to benefit food insecure populations, and the planet as a whole if more targeted research and conducive policies are implemented. The purpose of this paper is to outline the state of the science regarding edible insects, define a research agenda, and recommend policy action to support the growing industry. Edible insects are not a panacea for current challenges, but they have the potential to confer numerous benefits to people and the environment. Rigorous research is needed to establish optimal farming methods, strengthen food safety, understand health impacts of consumption, explore consumer acceptance, tackle ethical considerations, and investigate economic viability. A clear definition for insects as food, industry guidance support for obtaining generally regarded as safe designation, and collaboration by industry stakeholders to develop production standards will also help move the industry forward. Generating and galvanizing knowledge sharing networks, investing in critical interdisciplinary research, and advocating for conducive policies that support emerging entrepreneurs will be necessary to capitalize on the benefits of edible insects in the future.
... Insects are nutritious foods (RUMPOLD & SCHLÜTER, 2013) because of their high (20 to 76% of dry matter) and valuable protein content, but it is highly variable because of the wide variety of species, and its value also differs depending on the metamorphic state of the insect. Insect proteins contain measurable amount of essential amino acids such as tryptophan, lysine, and histidine (COLLAVO et al., 2005). Insect proteins are highly digestible (77-98%), although the exoskeleton -due to the presence of chitin -is lowering it (RAMOS-ELORDUY et al., 1997). ...
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Insects are alternative protein sources as nutritious novel food. However, there are some risks associated with the consumption of insects, even if rearing in controlled systems. Except for a recent EFSA opinion on the safety of insects as food, the European law is not conclusive regarding using insects as food products. Insects may be associated with microorganisms, but the prevalence of pathogens is usually lower than in case of other animal proteins. Insect proteins can induce allergic reactions, but only few studies are available on allergic reactions due to insect ingestion, and direct hypersensitivity to insect protein has not been proven. Some insect species are considered toxic, because some toxic substances are accumulated from toxic plants or are synthesized by the insects. However, there are few reports available about adverse reactions caused by insect consumption. Insects and insect derived food products may contain hazardous chemicals such as heavy metals, dioxins, mycotoxins, plant toxins, biocides, and veterinary drugs. However, data on hazardous chemicals in reared insects and accumulation of chemical contaminants from the substrates are limited. This review is not demonstrating the safety of insects as a food category, but the possibility of insects for human consumption with no more hazards than other animal products.
... The energy content of insect species shows similar or higher values compared to traditional meat products, with the energy depending on fat content (Kou rimská and Adámková, 2016). Insects have a high-quality protein content due to the presence of all the essential amino acids in the recommended ratios (Collavo et al., 2005;Belluco et al., 2013). A review of food composition data for edible insects has been provided by Nowak and co-workers (Nowak et al., 2016). ...
... The energy content of insect species show similar or higher values compared to conventional meat products (Table 1), but it depends on their fat content [19]. Insects have a highquality protein content due to the presence of all the essential amino acids in the recommended ratios [20,21]. Amino acid composition is also favorable. ...
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An insect as food, consuming insects, is gaining popularity in the Western cultures in the past few years. There are undoubtedly positive advantages to consuming insects in the place of consuming traditional meats such as beef, chicken or pork. Economics and health, supply and demand, cost and the need for adequate nutrition, are in play here. The ever-increasing world population will face serious issues in the not so distant future. Providing affordable, good quality and nutritious food for every human being is a problem of today. Using insects, as food products (or ingredients) may afford somewhat of a solution to these serious problems. To complement already-published reviews dealing with environment and product, we focus here on a review of the nutrition-related issues addressable by introducing insects into the diet. There is an emerging body of knowledge about the nutritional advantages of insects. This mini-review provides an analysis about the most recent state of the topic, the nutritional characteristics of edible insects, coupled with the twin issue in Western cultures of the response of consumers to the notion of insects.
Background Edible insects are considered as traditional foods in over 100 countries of Asia, Africa, and South America. Apart from this traditional aspect, edible insects are gaining increasing interest as alternative food sources for the increasing world population. Scope and approach The purpose of this research was to give an overview on several aspects of edible insects: nutritional characteristics; physical, chemical, and microbiological hazards; presence of antinutritional substances or allergens; gathering and farming; production technologies and patents; legal status worldwide; socio-economic and ethical implications. Key findings and conclusions Edible insects supply amounts of protein, fat, vitamins, and minerals comparable to those of meat. Although the studies on the environmental sustainability of insect farming are still few, it is generally recognized their limited requirements for land and reduced emissions of greenhouse gases. Nevertheless, not all the species can be bred as a consequence of their specific temperature and light requirements. Insects can be considered as safe from a microbiological point of view but can contain residues of pesticides and heavy metal. Attention must be paid to the cross-reactions among allergens found within some insect species. Edible insects can be consumed as whole insects but, in order to increase their acceptability, they can be processed into an unrecognisable form. Many inventions concerning insect processing have been patented. The European Union has a specific new Regulation on novel foods that established an authorization procedure to sell insect-based foods unless their safe consumption for longer than 25 years in third countries is demonstrated. Farming insects can offer revenue opportunities mainly in developing countries.
It was gratifying to be invited to prepare a third edition of this book, which first appeared in 1951. Preliminary discussions with the publishers, however, revealed a considerable challenge in the present high costs of printing, so that changes and some improvements were clearly necessary to justify the venture. It was immediately apparent that the chapter on chemical control measures would have to be substantially re-written, because of the great changes in usage due to resistance and the regulations introduced to prevent environmental pollution. Also, I decided to expand the scope of the book by increased coverage of the pests of continental Europe and North America, including some new figures and keys in the Appendix. These two undertakings resulted in considerable expansion in length, with about 370 new references and 250 additional specific names in the Index. In order to avoid too alarming an increase in price, I decided to sacrifice three chapters from the earlier editions: those dealing with the structure and classification of insects, their anatomy and physiology, and their ecology. Readers who require basic biological information on insects should buy one of the various short introductions to entomology available.
A study was undertaken to determine the composition of the body material of alates of Macrotermes falciger and to investigate the nutritional value of termite material when fed to white rats. Termites were found to contain 44,3 % fat and 41,8 % protein, on a dry mass basis, and to have a calorific value of 3,2 ± 0,042 Megajoules/100 g. Incorporating termite material into commercial rat pellets at various levels produced no adverse effects on the rats. A full amino-acid analysis of termite protein is given and three unidentified amino-acids were recorded. A protein efficiency ratio of 1,7± 0,1 was obtained for termite protein, and digestibility of termite material was found to be poor, compared to that of casein, when fed to white rats.