Insects can directly provide several products we use in our daily lives. Silk from the silkworm, shellac from the lac scale, butterflies for jewelry, honey from honeybees, and dye from the cochineal scale. These are examples of insects which provide a primary benefit to man; moreover, insects also provide many secondary or indirect benefits to man. For example, pollination of fruit and nut crops, biocontrol agents of weeds and insects, and as scavengers of carrion.
Insects provide direct products and they provide services.
The honey bee is perhaps the best known and respected insect in the world. When the Europeans first came to America, they found many flowers, fruits, and vegetables, but no honey bees. In fact, honey bees were not introduced into the New World until the 17th century and were called by Native Americans the white man's fly. The honey bee is a very efficient pollen gatherer and today is the most important pollinator of our commercial crops.
Source:
The major raw material for honey is nectar gathered from plant nectaries. A small percentage of honey is made from
honeydew secreted by aphids.
Composition:
Most nectars contain water and sugar, mainly sucrose; the same sugar that is in table sugar. As the nectar is converted
to honey, the water content is reduced to between 16 and 19 percent and the glucose is converted by invertase mainly
to fructose (the most sweet common sugar) and glucose (the least sweet sugar, corn syrup). Each nectar also contains
a unique blend pigments, nutrients, and other components. This is what gives honeys different tastes depending
on the major nectar source. Honey also contains many vitamins, but often in concentrations too low to be used as
a supplement.
As honey ages, it crystallizes; you have probably noticed this in your own honey jar. But, honey vary rarely spoils; in fact, 3000 year old honey has been found in the tombs of the pharaohs. In fact, honey can be used as an antiseptic.
It is estimated that a bee consumes 6 to 10 pounds (3 to 4.5 kg) of honey for each pound of the wax that it secretes in small flakes from glands on the underside of its abdomen. The beeswax is obtained, after removal of the honey, by melting the honeycomb, straining the wax to remove impurities, and pressing the residue to extract any remaining wax. The purified wax is then poured into molds to solidify. Color and quality are preserved by melting the wax in water, avoiding direct heat; the wax may also be bleached.
Beeswax is used for candles (religious ordinances often specify its use for church ceremonial candles), for artificial fruit and flowers, and for modeling wax. It is also an ingredient in the manufacture of furniture and floor waxes, leather dressings, waxed paper, lithographic inks, cosmetics, and ointments.
Shellac has been used since 1200 BC and is made from an insect called the lac scale. The lac scale is a native of India and Burma and it's host plant is related to the fig trees. The word lac is derived from the Sanskrit word, laksha which means 100,000 and refers to the large number of the minute insects required to produce lac. All female scale insects are wingless and the lac females cover their bodies with a resinous secretion. The resin hardens into a shield. Because the lac insect is sedentary, densities on branches can become very high. Branches on the host tree that become highly coated with the resin are referred to as a stick lac.
The stick lac is ground up to free the lac granules that are crushed and boiled in water. The lac floats to the surface of the water and is skimmed from the surface and dried in the sun. After the lac is dried, it is placed in burlap bags and stretched over a fire. As it is heated, the bags are twisted and the melted lac drips out. Before the lac hardens it is stretched like toffee. After the lac hardens, it is broken up into pieces and sold. About 17,000 to 90,000 lac insects are needed to produce a pound of lac.
Besides shellac, lac is the basic ingredient of an amazing list of articles, stiffening agents in the toes and soles of shoes and felt hats, shoe polishes, artificial fruits, lithographic ink, glazes in confections, photograph records, playing card finishes, and hair dyes.
Another scale insect that is used by man is the cochineal scale. It feeds on cacti in Mexico and is used to produce a carmine colored dye. The Aztecs used cochineal to produce a red dye for use in food-stuffs and painting. The Spaniards enslaved the Aztecs to produce the dye which was shipped back to Spain.
The insects are carefully brushed from the cacti into bags and are then killed by immersion in hot water or by exposure to sunlight, steam, or the heat of an oven; much of the variety in the appearance of commercial cochineal is caused by the differing modes of treatment. It takes about 70,000 insects to make one pound of cochineal.
Although for most uses cochineal has been replaced by synthetic dyes, it continues to be used as a coloring agent in cosmetics and beverages. Many other scale insects have also been used to make dyes. Kermes a brilliant red dye was used by the Greeks and it was so prized by the Romans that the insects were used as tribute from conquered nations. Margarodes another dye produced from scale insects was harvested about the time of feast day for St. John, hence it was called St. John's Blood.
The Aleppo gall has been used since the time of the Greeks as a nonfading ink. It is also used by the United States Treasury in the formula for money ink. The gall is made by a small wasp, the female deposits an egg on oak trees found in eastern Europe and in western Asia. Once the larva starts to feed, the plant reacts by forming a cancerous like growth, called a gall. There are many types of insect galls, I am sure you have seen the one which forms on golden rod.
Sericulture or the culturing of silkworms is at least 4000 years old. The silkworm moth is a completely domesticated insect and is no longer capable of living in the wild. Silk is prized as a fabric because it is finer than human hair, lighter than cotton, and stronger than steel. In 1881 a man was shot in the chest at close range by a pistol. But there was no bleeding. When examined the bullet was found to have penetrated his jacket, bones, and tissues. But a silk handkerchief was not torn and was pushed into the wound where it stopped the bleeding.
Several historical offshoots are related to sericulture. In 19th century France, sericulture was an important industry but the silkworms were dying of a mysterious disease called Pebrine disease. Louis Pasteur was begged by the French government to help find a cure for the disease which was ruining the French sericulture industry. Five years later Louis Pasteur demonstrated that the disease was contagious and was spread by microscopic creatures. The theory of disease contagion was based on Pasteur's work with Pebrine disease.
In an attempt to start a North American silk industry a Eurasian moth, the gypsy moth, was imported into Massachusetts. The moth did not prove to be a very effective silk producer but it became very important when it escaped and became one of the most devastating pests of trees in the Northeast. Today it has spread as far west as Minnesota.
Today, dragline silk of the golden orb-weaving spider, Nephila clavipes, is being investigated as an even stronger more resilient silk. It is tougher, stretchier, and more waterproof than insect silk. Today's synthetic fibers can not match it. Synthetic spider silk will be used to make stronger ropes, nets, seat belts, and parachutes, rustfree panels and bumpers for automobiles, and medical supplies such as sutures, bandages, artificial tendons & ligaments, and supports for weak blood vessels.
Since the beginning of time humans have used various insects as cures for sicknesses, such as leprosy, fever, headaches, wounds and many other as maladies. Today, many Chinese use insects for everything from tinnitus to dermatitis. Some of these cures are documented to be effective.
|
Affliction |
Cure |
| Epilepsy | Powdered cankerworm ashes. |
| Bleeding | Ashes of cankerworm in nostril. |
| Earache | Oil from soaking stag beetle. |
| Fevers | 1. Dung beetles tied in a linen cloth and attached to the body with a red string. 2. Powdered bedbugs. |
| Hydrophobia | Blister beetles. |
| Dropsy | Blisterbeetles, Cockroaches. |
| Colic | Ladybird beetles. |
| Toothache | Ladybird beetles. |
| Worms | Cockroaches. |
| Tetanus | Cockroach tea plus poultice of boiled roaches over the wound. |
| Indigestion | 1. Cockroaches fried with oil and garlic. 2. Cockroaches steeped in Pisco (liqueur). |
| Malaria | Seven bedbugs plus beans. |
| Leprosy | Bots fly larvae, oil from cloth moth, ants. |
| Baldness | Powdered Mackerel flies |
| Gout | Ants |
| Palsy | Ants |
| Headaches | Wasp nests |
| Eye Irritations | Bedbugs, salt and human milk, Fly water |
| Snake Bites | Bedbugs |
| Warts | Oil from clothes moth |
| Deafness | Oil from clothes moth |
| Ulcers | Oil from clothes moth plus tar |
| Scabs | Oil from clothes moth plus tar |
| Typhus | Silkworm excrement |
| Strokes | cockroaches |
| Constipation | Wood-louse, five gnats |
| Diuretic | Wasps |
| Cuts | Honey |
| Scurvy | Black pine ants |
| Arthritis | Hornet nest poultice, two parts ants plus three parts alcohol |
Blister beetles contain a chemical called, cantharidin, which has been used since the days of the Greeks and Romans as a love potion. In fact, as late as the 1940's cantharidin could still be found in pharmacies of England, Belgium, Spain, and Italy. Although we have blister beetles in this country they are not the same species which has been used in Europe. Cantharidin causes blisters when applied to the skin, hence the name, blister beetle. When taken internally, it causes inflammation of the kidneys and enlargement of the reproductive organs, specifically painful and prolonged erections in males. Cantharidin is a powerful poison, which can cause mortality with as little as 0.5 mg/kg of body weight. Horses are especially sensitive to cantharidin and each year, horses die from eating blister beetle contaminated hay.
During the Civil War, the wounded often did not receive prompt treatment. When finally examined, some of the casualties had fly maggots in the wound area. The doctors observed that wounds which were infested with maggots seemed to heal faster, there was less infection, and amputation was not needed as often.
The maggots are larvae of the blowfly. These maggots only feed on dead or decaying flesh and do not harm living and healthy flesh. Additionally, they excrete urea which acts like an antiseptic, thus keeping the wound clean. In fact, these maggots were used in hospitals to clean wounds until cheaper antibiotics and antiseptics were found. Today, in severe burn cases where the old skin has to be removed or for wounds that will not heal, maggots are still used.
Ants from the silk cotton tree collect lint that can be used as a bandage to stop bleeding. Spider webs also help stop bleeding. If the wound is too large for bandaging, you can try soldier ants. By holding the wound together and letting the ants bite so that their mandibles go across the wound, they will pull the tissue together and suture the cut closed. They do not let go even if their bodies are cut off.
An old-fashioned cure for stiff joints is a bee sting. Beekeepers have less arthritis than most people and they claim that frequent bee stings keep their joints supple.
Many cultures consider insects a delicacy and some may not have survived without the use of insects in their diet. It is not unusual to see a Chinese child munching on a diving beetle during a stroll through a park. Native Americans used grasshoppers to sustain themselves during the long winter months.
How many of you enjoy lobster tails or crab legs? Remember that they are closely related to insects. Crabs and lobsters feeds on decaying animals, so what would you rather eat, something that eats dead fish heads or nice clean plants?
Many of our foods have various levels of insects as contaminants. Examples for some foods are given below.
30 fruit fly eggs per 100 grams or 15 eggs and 1 larva per 100 grams or 2 larvae per 100 grams
Food Defect Action Level (U.S. Food and Drug Administration)
Food
Insect Contaminant
peanut butter
50 insect fragments per 100 grams
raisins
10 or more insects and up to 35 fruit fly eggs per 8 oz
cherries
4% of fruits can be infested with insects
tomato sauce
canned sweet corn
two 3 mm or longer larvae of corn borer or corn ear worm per 24 cans
It appears that even if you would rather not consume insects, your really don't have a choice in the matter. Some estimate that we indirectly consume about 1 to 2 lb. of insects a year.
Are insects nutritious? We need vitamins, minerals, carbohydrates, fats and proteins to maintain good health. We must get vitamins from our diet, we can not manufacture them. Silkworm pupae have ample amounts of vitamin A, locusts are rich in riboflavin and niacin, and honey bee larvae contain high amounts of vitamin D.
Insects are a good source of energy, protein, vitamins, and minerals.
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Last updated Dec. 30, 2000
Gary Brewer