Book Review

Los insectos comestibles en el mexico antiguo. [Edible Insects in Old Mexico.] Julieta Ramos-Elorduy and Jose M. Pino Moreno. 1989,108 pp. A.G.T. Editor, S.A., Progreso 2O2-Planta Alta, C.P. 11800 - Mexico, D.F. (In Spanish, paperback.)

From their own extensive field work and from historical documents, the authors describe how insects contributed to the diet of Mexicans in the past, before the Spanish Conquest.  Of the 247 species known by the authors to be consumed in Mexico, 70 species are treated in this book.  Some of Sahagun's accounts from the early 16th Century are quoted and some of his drawings are duplicated in order to establish the antiquity of use of many species.  Some insects such as escamole ants and ahuahutle, the eggs of aquatic bugs (Hemiptera), were held in such high esteem that they were used to pay taxes to the Emperor Montezuma.

The book is divided into Prolog, Preface, Introduction, Chapters 1-4, Appendices and Bibliography.  In Chapter 1 (pp. 9-45), the early use of the various species is documented.  Species discussed include 1 from the Order Odonata (dragonflies), 7 species from Order Orthoptera (grasshoppers), 1 from Anoplura (lice), 13 from Hemiptera (true bugs), 17 from Coleoptera (beetles), 9 from Lepidoptera (caterpillars), 2 from Diptera (true flies), and 20 from Hymenoptera (bees, ants, wasps).  Many common names are identified, for example a total of 11 for the leafcutter ants, Atta cephalotes and A. mexicana.

In Chapter 2 (pp. 47-56), nutritional value of insects is discussed.  Most, if not all of the data (5 tables) are drawn from previously published work by these authors.  It should be noted that work published prior to the late 1980s by the senior author was under her then-married name, de Conconi.  The insects highest in protein content are the grasshoppers, with the five species analyzed ranging from 70.9% to 77.6% on a dry weight basis, and the wasps, six of seven species analyzed ranging from 61.4 to 72.0%. Protein digestibility in nine species examined ranged from 77.9% to 98.9%. From amino acid data on 18 species, the insects generally surpassed 1973 FAO (Food & Agriculture Organization) values except most were low in trytophan.  Insects comprising the ahuahutle and axayacatl (aquatic Hemiptera) were low in methionine/cysteine, but rich in tryplophan.

In Chapter 3 (pp. 57-65), the authors present a figure (representative for south-central Mexico) showing the seasonal distribution of edible insect consumption by month for 63 species.  Elevational (climate) and vegetational differences variously modify these distribution patterns in other parts of the country.  Of the species discussed, 58.6% are most abundant during the summer and fall (rainy season), while 29.2% are more abundant in the spring (dry season).  About 12% are found also during the winter (dry).     
         
In Chapter 4 (pp. 67-75), the authors present a map showing distribution of 23 ethnic groups in central and southern Mexico and

discuss consumption of edible insects by the different groups.  Which insects are consumed by which ethnic groups appears to be determined largely by which insects are abundant in a given ethnic territory.  Some widely distributed insects are consumed by all ethnic groups.  The early manuscripts consulted by the authors give little clue to differences in insect foods of different groups.  The authors suggest that, although "mestizos" (Pima-Nahua ethnic group) are found all over Mexico and have probably had the highest consumption of edible insects, it may be less common now because of acculturation than in groups which have had less exposure to "roads, radio, television and tourism, and the distribution of processed foods by the multinational companies." These poorer groups have tended to "preserve their culture and vivid memories of their ancestors' lifestyle." The authors suggest that because of the large territory they occupy in south and central Mexico, the Zapotecos, Mixtecos, Otomies and Nahuas are the ethnic groups with the highest consumption of edible insects.

The authors cite some of their recent papers in describing "rustic cultivation" of several species.  In exploiting nests of the escamoles ants (genus Liometopum), for example, people are careful to leave dried nopal or maguey leaves or dry grass to aid the ants in reconstructing the nest. To help preserve humidity, fresh herbs are added, and the entrance is sealed with a large rock covered with fresh leaves.  In this way, the nest can be exploited every year or even two or three times during a year.  Wasps are cultivated by bringing the small foundation combs from the forest and hanging them from the houses until they are large enough for exploitation.

The "worm of madrono," Eucheira socialis (Lepidoptera: Pieridae), is also "cultivated." The larvae construct large silk pockets in which they remain during the day, going out to feed at night on the leaves of the madrono (Arbutus).  Each pocket has about 150 caterpillars, all of the same sex.  Cultivation consists of leaving three or four pockets to insure continued reproduction.  The authors state that this species practically disappeared in Nduayaco Apoala, State of Oaxaca, because of overexploitation (no effort was made to leave pockets of larvae uncollected).  The edible insects associated with the maguey are also cultivated by many ethnic groups.

Much information on collecting, preparation and marketing of the edible species is provided in the Appendix (pp. 79-93), which consists of 40 black and white photographs and accompanying legends.

This book is a valuable work on the use of insects as food in Mexico. another in a long series by these investigators.  As they point out (p. 75), insects should not be considered "unconventional food"; they have been eaten extensively in the past, and they continue to be consumed today.  The authors conclude by saying that edible insects "could become the 'good Samaritans' in our fight for survival."

(Ed.: We thank Ms. Heloisa Scholl, San Antonio, Texas, for translating the book.  Our review was prepared from her translation.

Recently from the Technical Journals JournalsJournals

Vane-Wright, RI. 1991.  Why not eat insects?  Bull.  Entomol.  Res. 81:1-4.  Biodiversity Programme, Department of Entomology, The Natural History Museum, Cromwell Rd, London SW7 5BD, UK.

The author borrows the title for this guest editorial from the title of Vincent Holt's 1885 book which was recently reprinted by the Natural History Museum [statutory name: British Museum (Natural History)] (see Newsletter Vol. 1, No. 2, p. 3, 1988, for a review of Holt's book].  Vane-Wright comes on as forthrightly as Holt did 100 years ago, by opening with this salvo: "To many people the idea of eating insects evokes only feelings of disgust.  For them, the answer to Vincent Holt's (1885) famous question seems obvious.  But what does biology tell us?  A wide range of vertebrates are insect eaters.  The common ancestor of primates is thought to have been an insectivore.  Most monkeys and apes eat insects -- including the chimpanzee, our closest living relative.  In contrast, many humans restrict their choice of meat to a few vertebrates, molluscs and crustaceans." He then cites Brian Hocking's 1960 [University of Alberta] statement, "We have about 50 more years of eating steaks and then perhaps we'll have to explore other sources of animal protein.. .."

Noting that western European cultures, and nations derived from them, are the only ones which do not use insects as food, the author says, "Food habits are not conditioned by nutritional tables, calorie counts or balanced diets.  What we eat is conditioned by religion, by tradition, by fashion -- in a word, by culture." Once established, food preferences are highly resistant to change.  Mentioning a number of insects consumed in Africa, Asia and the Western Hemisphere, including the famous mopani worm, Gonimbrasia belina, mbrasia belina, in Africa, Vane-Wright asks: "Could such insects become acceptable to western palates?  Perhaps.  My three-year old daughter finds fried mopani worms irresistible; her food preferences have yet to become fixed."

Unpredictability of supply is a major problem with wild insects for feeding urban societies, even though many insects are locally or periodically abundant.  Advanced culture techniques will be needed if city dwellers are to be reliably fed on a large scale.  The author notes that, "the very fact that eating insects belongs to the hunter-gatherer stage of human evolution may be a major factor in their rejection by western people; we may unconsciously reject entomophagy as primitive." Although some insects are difficult to process, others are easy: "dry-roasted mealworms are readily made from bran-fed Tenebrio molitor [beetle] larvae simply by freezing, washing, and then roasting the grubs at 95°C for two to three hours.  They taste a bit like potato crisps (but are far more nutritious)."

Relative to safety, "Green or brown plantfeeders, or pale unicolorous larvae are generally thought to be the most suitable."  Hairy or spiny insects may irritate, and brightly colored species may be poisonous.  Insects should be processed immediately and stored

dry (to stop growth of toxic molds) because dead insects deteriorate rapidly.  Cooking is always desirable because some insects carry parasites.

Vane-Wright asks whether, despite insects being a wholesome source of protein, fats and other nutrients, there is any compelling economic reason for using them as food.  His answer: "Well, there may be.  Raising conventional protein animals, such as cattle, is having a major effect on the surface of the planet -- large areas of forest burned to make way for ranching, with all the problems that this short-term economic solution brings -- including greenhouse gases released by cattle effluent." Also, stimulating the idea that insects are desirable food could promote additional concern for the conservation of biodiversity, as well as reducing pesticide pollution and returning grazing land to forest.

The author concludes: "Insects have an undeservedly bad reputation.  A handful of noxious species has meant that, too often, they are all seen as enemies.  In their most infinite variety, insects could yet be our salvation.  Is it not time for economic entomologists to develop a more positive view of their value?  Why not eat insects indeed!" With only three pages in this review, Vane-Wright does about as well as can be done in covering the relevant ground.

El Boushy, A.R. 1991.  House-fly pupae as poultry manure converters for animal feed: a review.  Bioresource Technol. 38:45-49. Department of Animal Nutrition, Agricultural University, 6708 PM Wageningen, The Netherlands.

Author's Abstract: Poultry wastes can be converted into a high protein feedstuff for farm animals by upgrading with housefly pupae.  This process solves the problems of accumulation of poultry wastes which may not be attractive as soil fertilizer and cause pollution.  If this upgrading of manure takes place, a reasonable animal protein feedstuff will be created and partially solve the problems of human malnutrition by increasing the animal protein supply in the form of meat, milk, butter and eggs.

From the few published relevant data the following may be concluded.  The housefly-pupa meal is produced from caged layer manure.  This feedstuff is characterized by a high content of crude protein of 61.4% and further contains fat (9.3%), ash (11.9%) and metabolizable energy (10.38 MJ/kg).  The pupa meal is a good source of essential amino acids, mainly arginine (3.7%), lysine (3.8%) and methionine (1.6%). It is a relatively well-balanced protein source for poultry.

With an additional building to layer houses, it is possible to produce, continuously, upgraded manure composed of pupa mixed with manure residue, this stuff will be treated by heat up to 180°C to be sterilized, dried and may be used as a feedstuff in animal nutrition.