CHAPTER 3

 

                                     THE USE OF INSECTS AS FOOD IN MEXICO

 

Taxonomic Inventory

 Taxa and life stages consumed

 

Coleoptera

Buprestidae (metallic woodborers)

Chalcophora sp., larva

 

Cerambycidae (long-horned beetles)

Aplagiognathus spinosus Newman, larva, pupa

Aplagiognathus sp., larva

Arophalus afin rusticus Linn., larva, pupa

Callipogon barbatus Fabr., larva, pupa, adult

Lagocheirus rogersi Bates, larva, pupa, adult

Stenodontes cer. maxillosus Drury, larva, pupa

Trichoderes pini Chevr., larva, pupa

 

Chrysomelidae (leaf beetles)

Leptinotarsa decemlineata Say, larva

 

Cicindelidae (tiger beetles)

Cicindela curvata Chevr., larva

Cicindela roseiventris Chevr., larva

 

Curculionidae (snout beetles, weevils)

Metamasius spinolae Vaurie, larva, pupa

Rhynchophorus palmarum Linn., larva, pupa

Scyphophorus acupunctatus Gyllenhal, larva, pupa

 

Dytiscidae (predaceous diving beetles)

Cybister explanatus Leconte, larva, pupa, adult

 

Histeridae (hister beetles)

Homolepta sp., larva

 

Hydrophilidae (water scavenger beetles)

Tropisternus tinctis Sharpe, larva, pupa, adult

 

Passalidae (bess beetles)

Oleus reinator Trequi, larva, pupa

Passalus af. punctiger Lep. & Serv., larva, pupa

 

Scarabaeidae (scarab beetles)

Melolontha sp., larva

Phyllophaga rubella (author?), larva

Phyllophaga spp., larvae, pupae

Strategus sp., larva

Xyloryctes spp., larvae, pupae

 

Tenebrionidae (darkling beetles)

Tenebrio molitor Linn., larva, pupa

 

Family uncertain

Paxillus leachi M. & Y.,larva

Rhantus sp., adult

 

Diptera

Ephydridae (shore flies)

Hydropyrus (= Ephydra) hians Say, larva, pupa, adult

Mossilus (= Gymnopa) tibialis Cresson, larva

 

Muscidae (filth flies)

Musca domestica Linn., larva, pupa

 

Stratiomyidae (soldier flies)

Stratiomyid spp., larvae

 

Syrphidae (flower flies)

Copestylum haaggii J., larva

 

Hemiptera

Belostomatidae (giant water bugs)

Abedus ovatus Stal., nymph, adult

Abedus sp., nymph, adult

Belostoma sp., nymph, adult

Lethocerus sp., nymph, adult

 

Coreidae (leaf-footed bugs)

Acanthocephala luctuosa S., nymph, adult

Pachilis gigas B., nymph, adult

 

Corixidae and Notonectidae

Corixidae (water boatmen)

Corisella edulis J., nymph, adult

Corisella (= Corixa) mercenaria Say, egg, nymph, adult

Corisella texcocana Jacz., egg, nymph, adult

Krizousacorixa (= Kirzousacorixa; = Ahauhtlea) azteca, egg, nymph, adult

Krizousacorixa femorata Guerin-Meneville, egg, nymph, adult

Notonectidae (backswimmers)

Notonecta unifasciata Guerin-Meneville, egg, nymph, adult

 

Naucoridae (creeping water bugs)

Naucorid sp./spp., nymphs, adults

 

Pentatomidae (stink bugs)

Edessa conspersa Stal., nymph, adult

Edessa mexicana Stal., nymph, adult

Edessa petersii Stal., nymph, adult

Euchistus crenator Stal., nymph, adult

Euchistus lineatus Walk., nymph, adult

Euchistus strennus Distant (= zopilotensis Distant), nymph, adult

Euchistus (= Atizies) sufultus Smith, nymph, adult

Euchistus (= Atizies) taxcoensis Ancona, nymph, adult

Pharylpia fasciata (author?), nymph, adult

 

Family uncertain

Brachymona arcane tenebrosa M., nymph, adult

 

Homoptera

Aphididae (aphids)

Aphid honeydew

 

Cicadidae (cicadas)

Proarna sp., adult

Tibicen puinosa S., adult

 

Membracidae (treehoppers)

Hoplophorion (= Metcalfiella) monograma Germar, nymph, adult

Umbonia reclinata Germar, nymph, adult

Umbonia sp., nymph, adult

 

Hymenoptera

Apidae (honey bees, bumble bees)

Apis mellifera Linn., egg, larva, pupa

Bombus diligens (author?), adult

Bombus formosus (author?), adult

Bombus medius (author?), adult

Lestrimelita limao Sm., egg, larva, pupa

Melipona beeckei Bennet, egg, larva, pupa

Melipona fasciata querreroensis Schw., egg, larva, pupa

Partamona sp., egg, larva, pupa

Scaptotrigona mexicana G., egg, larva, pupa

Trigona jaty Fabr., egg, larva, pupa

Trigona nigra nigra Cress, egg, larva, pupa

Trigona sp., egg, larva, pupa

 

Diprionidae (conifer sawflies)

Neodiprion guilletei (author?), prepupa

 

Formicidae (ants)

Atta cephalotes Latr., adult reproductive

Atta mexicana Bourmeir, adult

Liometopum apiculatum Mayr., egg, larva, pupa

Liometopum occidentale var. luctuosum W., egg, larva, pupa

Myrmecosystus (= Formica) melliger Llava (= melligera), adult

Myrmecosystus mexicanus W., adult

Pogonomyrmex sp., larva, pupa

 

Sphecidae (sphecids or mud daubers)

Ammophila sp., immature stages

 

Vespidae (wasps, hornets)

Amnophila sp., immature stages

Brachygastra azteca (Sauss.), immatures

Brachygastra (= Nectarinia) lecheguana (Latr.), immatures

Brachygastra mellifica (Say), immatures

Mischocyttarus sp., immatures

Parachartegus apicalis (Fabr.), immatures

Polistes canadensis (Linn.), immatures

Polistes instabilis (Sauss.), larva, pupa, adult

Polistes major Palisot de Beauvois., egg, larva, pupa

Polistes sp., egg, larva, pupa

Polybia diguetana du Buysson, immatures

Polybia occidentalis bohemani Holmgren, immatures

Polybia occidentalis nigratella du Buysson, immatures

Polybia parvulina Richards, immatures

Polybia spp., eggs, larvae, pupae

Vespula squamosa Drury, immatures

  

Xylocopidae (carpenter bees)

Xylocopa sp., larval food

 

Isoptera

Miscellaneous termites

Scientific name(s) unreported

 

Lepidoptera

Cossidae (carpenter moths, leopard moths)

Comadia (= Xyleutes; = Cossus) redtenbachi Hamm., larva

 

Geometridae (measuringworms)

Synopsia mexicanaria Walk., larva

 

Hepialidae (ghost moths, swifts)

Phassus sp., larva

Phassus trajesa Linn., larva

Phassus triangularis E., larva

 

Megathymidae (giant skippers)

Aegiale (= Acentrocneme) hesperiaris Kirby, larva

 

Noctuidae (noctuids)

Ascalapha (= Erebus) odorata Linn., larva

Heliothis zea Boddie, larva

Spodoptera frugiperda J.E. Smith, larva

 

Pieridae (whites, sulphurs)

Catasticta teutila Doubleday, larva

Eucheira socialis Westwood, larva, pupa

 

Psychidae (bagworm moths)

Bagworm tea

 

Pyralidae (snout moths, grass moths)

Laniifera cyclades Druce, larva

 

Saturniidae (giant silk moths)

Arsenura armida Cramer, larva

Hylesia frigida Hubner, larva

Hylesia sp., larva

Latebraria amphipyroides Guenee, larva

 

Sphingidae (hawk-moths, sphinx moths)

Hyles lineata (author?), larva

 

Family uncertain

Scientific name(s) unreported

 

Megaloptera

Corydalidae (dobsonflies, fishflies)

Scientific name(s) unreported

 

Odonata

Aeschnidae (darners)

Anax sp., nymph, adult

 

Orthoptera

Acrididae (short-horned grasshoppers)

Arphia fallax Sauss., nymph, adult

Boopedon flaviventris Bruner, nymph, adult

Boopedon sp. af. flaviventris Bruner, nymph, adult

Encoptlophus herbaceous Sauss., nymph, adult

Melanoplus femurrubrum DeGeer, nymph, adult

Melanoplus mexicanus Sauss., nymph, adult

Melanoplus sp., nymph, adult

Ochrotettix cer. salinus Burm., nymph, adult

Osmilia flavolineata DeGeer, nymph, adult

Plectrotettra nobilis Walk., nymph, adult

Schistocerca paranensis Burm., nymph, adult

Schistocerca sp., nymph, adult

Spharagemon aequale Say, nymph, adult

Sphenarium histrio Gerst., nymph, adult

Sphenarium magnum Marquez, nymph, adult

Sphenarium purpurascens Charp., nymph, adult

Sphenarium spp., nymphs, adults

Trimerotropis sp., nymph, adult

Tropinotus mexicanus Brunner, nymph, adult

 

Blattidae (cockroaches)

Medicinal use

 

Gryllidae (crickets)

Scientific name(s) unreported

 

Gryllotalpidae (mole crickets)

Scientific name(s) unreported

 

Romaleidae (lubber grasshoppers)

Romalea colorata S., nymph, adult

Romalea sp., nymph, adult

Taeniopoda sp., nymph, adult

 

Tettigoniidae (long-horned grasshoppers)

Microcentrum sp., nymph, adult

 

Trichoptera

Hydropsychidae (net-spinning caddiceflies)

Leptonema sp., larva

 

 

            In her book on insects as a future source of protein (1982a), Dr. Julieta Ramos-Elorduy de Conconi states that, "Mexico can be described as a country where there is so much hunger that the country doesn't feel it."  In some areas of the State of Oaxaco and in some arid regions of the country, insects are the only significant source of protein. The author presents in tabular form a list of 71 species of insects that are consumed in Mexico, listing them by order and family and giving the developmental stage(s) that are eaten and the geographical location [state(s)] where eaten.

            Analyses of samples from Mexico have revealed a crude protein content (dry weight) between 31% and 72% in most species. Most amino acids (including lysine) surpass FAO standards, but in keeping with generally-obtained results from elsewhere, most insects are low in methionine and tryptophan. The author notes the need for more data on bioavailability, particularly when insects are used in conjunction with other common foods in the rural diet.

            Conconi proposes that the "industrialization" of insects (the establishment of small industries in the countryside for the mass-culture of insects as food) would work both to the benefit of rural economies and better nutrition in the country as a whole. Relative to their exploitable attributes, it is pointed out that insects are the dominant animal group on earth, they are adapted to a wide variety of ecological conditions, and many have high reproductive capacity and short life cycles. Relative to their acceptability as food, a survey taken in the Federal District (Mexico City) revealed that 75% of the population is aware that there are edible insects in Mexico, 93% considered "industrialization" a viable project, 39% responded that they would use the resulting products, 29% that they would use them once in awhile, and 19% that they would try them only as a curiosity.

            Conconi demonstrates that edible insects are prominant in the rural markets, but in addition several species command high prices in Mexico City and other urban areas where they are purchased by people of various economic levels and are sold as delicacies in the finest restaurants. The author mentions that in 1981, the demand for "escamoles" (immature stages of the ant, Liometopum apiculatum) was so great that the price per kilogram went up to 1,000 pesos (more than U.S. $2 at the then-prevailing exchange rate).  "In Tlaxcoapan . . . . they are sold in restaurants like El Prendes, Las Meninas, Delmonicos, and Bellinghaussen, where 2 tacos with 50 grams of ants costs 300 pesos. They are served fried or with black butter, but the best way is fried with onions and garlic."

            The recorded history of edible insect use in Mexico goes back hundreds of years. The work of the great Spanish writer, Sahagun (1557; vide Curran 1937, 1951), reveals that the Aztecs knew a great deal about natural history, including the insects that are edible. As extracted from Curran's summary, the Indians ate honey from bees' and wasps' nests whenever they could find them, and the larvae and pupae were frequently eaten along with the honey. The Indians greatly relished the honey of the "honey ant," termed mequazcatl, and consumed the ant along with the honey. The corn ear worm was eaten with relish, along with the corn. All grasshoppers were considered edible and formed an important part of the diet during seasons when they were abundant. Curran reproduced a number of early native drawings taken from Sahagun's work, including the maguey caterpillar and several others that the Aztecs relished as food. Sahagun (1557 [1946]; vide Massieu et al 1958) also mentioned that the Indians ate the aquatic insects (Hemiptera) known as axayacatl after drying them in sunlight.

            In their English translation of Clavigero's (1786) "History of Lower California," Lake and Gray (1937) note that it describes experiences in the 1750's and they cite two references showing, first, the diversity of animal foods used by the Indians of northwestern Mexico and, secondly, the consequences of giving up insects as part of the diet. From Report of the Smithsonian Institution, 1864 (Lake and Gray, p. 93 footnote):  "There seem to have been few animals which the Indian did not eat. Father Baegert states that they lived chiefly on dogs and cats, horses and mules, mice and rats, lizards and snakes, grasshoppers and crickets, owls and bats, green caterpillars, 'an abominable white worm of length and thickness of the thumb,' and other insects and small animals."  A second footnote (p. 93) states:

 

            Under the instruction of the missionary the Indian was induced to give up the eating of many kinds of insects and worms, and to eat beef. From an economic point of view this was a mistake of the missionaries. The Mission Indians required an enormous amount of beef. It was not uncommon to have an Indian consume in a day from fifteen to twenty pounds of beef. Cattle stealing became a favorite pastime of the Indians, and at first it was difficult to increase the number of cattle at a Mission. Father Baegert wrote that 'for eight years I kept, ranging at large, from four to five hundred head of cattle, and sometimes as many goats and sheep, until the constant robberies of my own and the neighboring missions compelled me to give up cattle breeding. . . . The Indian never learned to eat pork nor to drink milk, and so he always demanded a generous supply of beef. . . (University of California Publications in American Archeology and Ethnology, Vol. VIII, Part I, p. 13).

 

            In a paper useful for comparative nutrient values, although no insects are included, Cravioto et al (1945) analyzed the major fruit and vegetable foods of Mexico for carotene, thiamine, riboflavin, niacin, ascorbic acid, calcium, phosphorus, iron, nitrogen, ash and total solids content. Massieu et al (1950) analyzed the tyrosine in several foods of high protein content: commercial samples of "zeina" and wheat gluten; "axayacatl" (nymphs and adults of the aquatic hemipteran genera Krizousacorixa, Notonecta and Corisella); "ahuahutle" (eggs of Krizousacorixa and Corisella); "maguey worms" or "meocuiles" (Acentrocneme [Aegiale =] hesperiaris); "jumiles" (hemipterans of the genera Atizies, Edessa and Euchistus [Euschistus =]); "acociles" (small crustaceans, Cambarus moctezumi); and "charales" (small freshwater fish, Chirostoma jordani). The crustacean and the fish are used as food in many regions of Mexico, while the use of the insects is limited to certain groups of the Mexican population. A very high tyrosine content was found in the "ahuahutle," nearly twice the amount found in "zeina" and more than twice the amount in the other materials tested.

            Cravioto et al (1951) analyzed several hundred Mexican foods for their nutritional value. Results obtained from insects (ahuautle, axayacatl, gusanos de maguey, and jumiles) are shown in Mexico Table 1 (see Cravioto et al p. 153). Also extracted from the lengthy table of Cravioto et al and included in Table 1 are data on "acocile," a crustacean, and "charales," a small fish (these data are discussed below under Massieu et al (1958)).

            Barrera and Bassols (1953) mention (vide Ramos-Elorduy and Pino 1989) that lepidopteran larvae, ahuahutle (Corixidae), and honey ants (Formicidae) were used as food by the Aztecs. Larvae of large cerambycid beetles (Cerambycidae) were eaten in the Ferreria Region of the State of Hidalgo, and caterpillars which grow in cactus (Pyralidae: Laniifera cyclades Druce according to Ramos-Elorduy and Pino) were eaten in Yucatan.

            Grimaldo et al (1957), pointing out the lack of information on cystine and tyrosine in previous amino acid studies on Mexican foods, reported the results of their analyses for these two amino acids. Included are data on ahuahutle, axayacatl, chapulines (grasshoppers), and jumiles (Mexico Table 2; see Grimaldo et al Table II, p. 6). The authors discuss their results in relation to whole milk protein, considered an appropriate standard for promoting growth and nitrogen retention. For comparisons, tyrosine values in the proteins of ahuahutle and axayacatl are borrowed from the previous study by Massieu et al (1950). Ahuahutle, with cystine at 4.64% of total protein, was the highest in this amino acid of the 58 foods that were analyzed, 34 of vegetable origin and 24 of animal origin. "Requeson," a product obtained from milk, was, at 4.48%, the only other sampled food that was close. The other insects were much lower than whole egg protein in cystine. Ahuahutle, at 11.10%, was much higher in tyrosine (as a percentage of total protein) than were any of the other sampled foods. The other insects were also higher than egg protein (Table 2) and higher than most other foods in tyrosine.

            Massieu et al (1958) conducted amino acid analyses on six primitive Mexican foods, four insects, a crustacean, and a small fish (Mexico Table 3; see Massieu et al Table 2, p. 213). Of ahuahutle, known also as "aguaucle" or "Mexican caviar," they state that several dishes which are typically Mexican are prepared with it today: "Usually it is eaten after it is mixed with eggs and fried; it is sometimes mixed into other popular foodstuffs. It tastes much like shrimp."  Jumiles "are eaten raw, fried, or roasted and ground, by several groups of the rural population, especially in tropical and sub­tropical regions."  Gusanos de maguey or "meocuiles" today are eaten after they have been fried in lard or in their own fat and rolled in 'tortillas.'  They are consumed by a number of people, especially those living on the high plateaus in Mexico where the Agave plant (maguey) is cultivated for the 'pulque' industry. The flavor of meocuiles is very much valued and in Mexico City they are considered delicacies."  Other foods discussed are "Acociles," small Crustacea belonging to the genus Cambarus, specifically C. moctezumi which live in Lake Xochimilco near Mexico City, and "charales," small fish (in this case Chirostoma jordani) which are common in the fresh water lakes near Mexico City and elsewhere. These crustaceans and fish, especially the latter, "are quite popular among groups in Mexico which have been considered to consume inadequate amounts of amino acids in the diet."

            The amino acid analyses of Massieu et al revealed that none of the insects are as high as the fish or crustacean in lysine, but axayacatl and jumiles contained a high level of tryptophan and ahuahutle was the richest in arginine and tyrosine (Mexico Table 3). Massieu et al also compare the nutrient composition of the six foods using the data of Cravioto et al (1951) (see Mexico Table 1).

            Ahuahutle, axayacatl, jumiles, and the fish were high in protein based on the conversion factor of N x 6.25. The jumiles and gusanos de maguey were rich in fat (ether extract), although the fat of the former included fats used to prepare them for market. Axayacatl was high in calcium although not nearly as high as the fish and crustaceans. Ahuahutle and axayacatl were among the samples high in phosphorus but the calcium-phosphorus ratio was very low in ahuahutle. Axayacatl was especially rich in iron, while the gusanos de maguey were relatively low compared to the other foods.  All of the foods were rich in niacin, especially ahuahutle and axayacatl, and these plus jumiles and the crustacean were high in riboflavin. Massieu et al conclude: "These primitive foods can contribute much toward the nutrition of those who consume them."

            Massieu et al (1959) describe the systematic program of studies conducted by the National Institute of Nutrition over the past 15 years on the composition of Mexican foods. The studies have included foods used frequently in the diets of precolombian Mexicans, and the authors suggest that some of these products "are potentially important, especially those of animal origin, because they could complement the drastic protein deficiency often observed in some sectors of the Mexican population."  Studies are needed, the authors say, to determine ways in which the use of some of these foods, which include insects, could be made more widespread and available in Mexican diets.

            Samples of the 190 foods included in the present study were obtained in local markets. Among the insects studied (Mexico Table 4), the authors noted the high protein and niacin content of "chapulin" (Sphenarium grasshoppers), and the protein, riboflavin and niacin of jumiles. "Tismitches" (Table 4; see Massieu et al, 1959, Table VIII, p. 64) apparently is a mixture of insect larvae, crustaceans and fish collected in areas like Tlacotalpan; the composition was not uniform, possibly because of seasonal changes in the proportions of the organisms collected. The dried product had a high vitamin content.

            MacNeish (1958) is cited by Callen (1963) as finding grasshopper wings and legs in two of 11 coprolites from Mexico. Callen examined coprolites supplied by MacNeish from two caves of the Sierra Madre in southwestern Tamaulipas, Mexico, and found parts of grasshoppers, beetles, bees, ants, wasps and termites. The material examined covered eight cultural phases spanning 7000 to 400 BC, but the author does not specify which phase(s) contained insects.

            Conconi (1974) points out that insects are the dominant animal group and have great reproductive potential, therefore, they are a natural resource that offers new food alternatives (vide Conconi and Burgess 1977).  In the 1970's, Conconi and colleagues at the National Autonomous University in Mexico City initiated an extensive research program on the nutritional value of Mexican insects.

            Conconi and Bourges (1977) cited several recent studies noting the poor nutrition that occurs in the arid and semiarid zones that make up a large part of Mexico, and stated that this makes it obligatory to search for new food alternatives that enrich the basic diet and fit within traditional Mexican food habits. They list 52 species of insects known to be consumed in Mexico, many of which have not been previously recorded as food. Species are listed according to insect order and family, and information is given for each species on the life stage(s) consumed and the geographic area (state) where consumed. The authors also present a world list of insects recorded as food (369 species), most of which, however, are, as stated by the authors, drawn from Bodenheimer (1951).

            The six species studied were all high in crude protein (dry weight basis), ranging from 58.3% to 71.0% (Mexico Table 5; see authors' Table 1). Except for methionine and tryptophan, and in the case of Atizies taxcoensis, lysine, amino acids exceeded F.A.O. (1957) recommended daily allowances (mg/16 mg/N). Thus, these insects are, in general, of intermediate protein quality. Studies are needed to determine their value as blended with other foods which are common in the rural Mexican diet. Conconi and Bourges emphasize that, except for the grasshopper, Sphenarium histrio, none of the species included in their study compete with man for food. Furthermore, four of the species, Atizies taxcoensis (jumiles), Cossus (Xyleutes =) redtenbachi (pink caterpillar), Corisella mercenaria (axayacatl), and juvenile stages of the ant, Liometopum apiculatum (escamoles), are endemic in arid zones, thus enhancing their importance as a food source.

            In addition to the data in Table 5, Conconi and Bourges conducted a proximate analysis on C. mercenaria, one of the "axayacatl" group, with the following results (dry weight basis): protein 68.74%, fat 11.13%, ash 5.53%, and carbohydrate 12.60%.

            Conconi and Pino (1979) conducted a study in eight counties of the high, semiarid Mezquital Valley (State of Hidalgo) which has long been considered one of the areas of poorest nutrition in Mexico. The soil is poor in organic matter and minerals and the alkalinity high enough to inhibit cultivation. Average calorie consumption in Hidalgo State is only 2,064 per day per person, and there is high infant mortality because of malnutrition. Malnutrition in the Mezquital Valley is even more severe with an average calorie consumption of less than 1,774 per day per person. The diet is based on corn, beans, chilies, quelite and a ration of pulque (liquor from the maguey), and consumption of products of animal origin (such as meat, eggs and milk) "is very rare."  Insects of one kind or another are commonly eaten daily, however, and the authors obtained proximate analyses on 13 species and on five plants which serve as hosts for seven of them (Mexico Table 6; see authors' Tables II, III and IV).

            It is readily seen by the data that the insects are many times higher in protein and fat than are the plants upon which they feed (Table 6). Protein ranges as high as 69.05% in the adult weevil, Metamasius spinolae, compared to 5.21% in nopal, the cactus upon which it feeds. Fat ranges as high as 58.55% in the larva of Aegiale hesperiaris compared to 3.60% in the maguey plant. The insects are all much lower in crude fiber. Conconi and Pino make the interesting suggestion that some plants that are widespread and characteristic of arid regions, but of limited food value, such as mezquite, madrono, and some cacti, could be used for cultivation of their associated insects, thus producing more protein of animal quality.

            In this first of a series of published abstracts by J.R.E. de Conconi and colleagues, Conconi and Pino (1980a) report that they have conducted proximate analyses on several species of edible insects: larvae of Phyllophaga rubella (Coleoptera); larvae, pupae and adults of Ephydra [Hydropyrus =] hians (Diptera); larvae of Erebus [Ascalapha =] odoratus [odorata =] (Lepidoptera), preserved in salt; and Abedus ovatus and Leptocerus sp. (Hemiptera). These insects ranged from 35% to 85% crude protein on a dry weight basis. Administration of the juvenile hormone analogue, Altocid ZR 515, to Locusta migratoria by sprinkling on the insects or on their food produced no significant difference in their nutritive value. Conconi and Pino (1980b) report preliminarily on the digestibility of insect proteins (see Conconi et al 1981a for the full report). Conconi et al (1981c) provide preliminary data on the protein quality of three edible species, Pachilis gigas, Euschistus strennus, and Ephydra [Hydropyrus =] hians (see Conconi et al 1982a for the full report).

            Conconi et al (1981a) determined the protein digestibility of nine insect foods (Mexico Table 7; see authors' Table 4). The data show, by column, respectively, protein as a percentage of dry matter, digestible protein as a percentage of dry matter, and the percentage of the protein that is digestible, using methods and criteria described by the authors. As shown, the percentage of the protein that is digestible ranged from 77.86% to 98.93% in the different species or species groupings. The authors discuss these results in relation to the daily intake of proteins that are considered adequate by various experts on nutrition, noting that Mexican nutritionists consider 25 grams per day per person to be, at best, minimal (this level of intake is well below FAO and U.S. standards).

            Conconi et al (1982a) present data on 11 species, including new data on amino acid content of six species (Mexico Table 8; see authors' Table 4). The most notable feature of this report is the high methionine/cysteine values found, for all six species exceeding FAO-OMS standards. The authors report protein chemical values, based on the 1973 FAO guidelines, for 10 species as follows (authors' Table 5): Sphenarium histrio 60%; S. purpurascens 65%; Atizies taxcoensis 10%; Pachilis gigas 58%; Euschistus strennus 56%; Cossus [Xyleutes =] redtenbachi 60%; Hydropyrus hians 42%; Musca domestica 58%; Atta mexicana 60%; Liometopum apiculatum immature reproductives 80%, immature workers 51%.

            Conconi et al (1983b) report amino acid analyses on several species not previously analyzed, i.e., the grasshoppers Boopedon flaviventris and Melanoplus mexicanus; the homopteran Hoplophora monograma; the bee Trigona sp.; the caterpillar Hylesia frigida, from the madrono tree; and the grub of the weevil, Scyphophorus acupunctatus from the maguey. The authors do not give the tabularized data in this abstract, but state that all of the insects analyzed meet FAO (1973) quidelines for all of the essential amino acids except tryptophan. The chemical value of H. monograma was 96%, which is excellent and the highest value found in any insect yet studied. The chemical value for the weevil, S. acupunctatus, was also high, 81%.  Conconi et al (1983c) conducted analyses of sodium, potassium and lithium in 28 species from different localities in Mexico. None of the samples contained lithium, and no relationship was observed between classification (order to which the insect belongs) and the quantity of sodium or potassium found.

            Conconi (1982b) presents in condensed form various points made in her book (Conconi 1982a).  Conconi et al (1983d) discuss the past use of insects as food by different ethnic groups in Mexico.  According to the authors, 38 species were included, but, in this abstract only 21 are mentioned and specific ethnic groups are not identified.  Robles et al (1983) report that 28 edible species were found to be used in a region in the southeastern part of the Federal District. Lepidoptera predominated. Most of the insects were collected and consumed locally, with only a few such as the escamole ants, ahuautle and axayacatl entering commerce.  Eerde (1980/1981) provides a popular account of insects as food, based on the work of Conconi and colleagues.

            Conconi (1984) re-emphasizes many of the points made in her earlier works (1982a,b), pointing out that the Mexican diet is based on corn, beans and chili, and that 24 of the 32 states are regarded as having inadequate nutrition (too few calories and too little protein). In the States of Hidalgo, Oaxaca, Chiapas and Puebla, insects supply a large part of the animal protein consumed by the inhabitants, and some species such as grasshoppers, caterpillars, stink bugs, wasps and ants are "commercialized" by the local people. Generally, the insects are eaten roasted or fried, "or they are boiled and then fried with onions and chilies and eaten in tacos."  Flavor varies from insect to insect: "For example, the white maguey worm tastes like crackles, grasshoppers generally assume the taste of the condiment with which they are cooked, such as chili piquin or lemon in garlic; 'escamoles' taste like nuts fried in butter, 'cuecla' larvae preserved in salt taste like herring, etc."  Insect dishes found in restaurants in Mexico, the United States and France include such as "escamoles in black butter," "chapulines in garlic," and "chinicuiles in curry."  The author concludes that:

 

            We don't know how much it would cost to cultivate insects as food; however, we believe that because of their high protein content, high digestibility, variety in food diets, high conversion efficiency, and great reproductive potential associated with a short life cycle, the useful biomass obtained would be significant when compared to other products which are used to obtain protein. That is why insects should be taken into consideration as a food alternative for a world in which human nutrition has been a huge problem.

 

            Conconi et al (1984a) listed 101 species of insects that had been found up to that time to be used as fo