Wax

Wax stoma with wax crystals

Natural wax is, chemically, “an organically-synthesized hydrocarbon generally composed of long alkyl chains with various other molecules such as fatty acids, esters, alcohols, and aromatic components.”  Okay, sure.  But what is wax?

Waxes are characterized as much by their properties as by their exact chemical composition.  Generally, waxes are hydrophobic (water-repellent), lipophilic (fat-loving), solid at most ambient temperatures, but malleable and with a low melting point.

Natural waxes are “organically-synthesized,” meaning that every wax found in nature was originally made in the body of a living creature.

This includes the so-called “mineral waxes”: ozokerite (and its derivative, ceresine), and montan wax, both of which are found in association with lignite (coal).  Paraffin wax and microcrystalline wax are derived from petroleum.  Both coal and petroleum are the result of the organic matter that is subjected to heat and pressure over a long (long) period of time.

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Photo credit: Ozokerite, from the collection of the Natural History Museum of Lille, courtesy of Wikimedia Commons

A large number of plants and animals (including insects) make wax, and put it to a variety of uses.  Human beings are no exception.

Which bring us to our first question: What is a property of wax that humans make use of, that is not found elsewhere in nature?

Well, let’s look at the properties one by one.

Waterproof.

The hydrophobic (water-repelling) nature of wax is by far its most widely-used property. Sheep produce lanolin (also called “wool wax” or “wool grease”) to waterproof their fleece (it also has antimicrobial properties).  Plants that produce wax usually do so as a means of preventing moisture loss from their leaves.  Similarly, people use the wax produced by other plants and animals as an emollient to “waterproof” their own skin, by including it in products like salves and lip balms.

Wax stoma with wax crystals
Epicuticular wax stoma with wax crystals, on a rose leaf.  Courtesy of Wikimedia Commons

Interestingly, lanolin is particularly prized for this use, as it closely resembles the compounds produced by the human body for the same purpose.  However, lanolin in its natural state is mixed with compounds that can cause allergic reactions.  Here is a brief but informative article about using using lanolin on your skin..

And here is one of the better (among the hundreds) of books about how make your own cosmetic products from wax:


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Wax is also one the preferred ingredients in wood polishes, which act as waterproofing for wood.  Wax polishes have been around for centuries (at least) and are relatively easy to make. Here’s time-honored recipe that has been around with only slight variations for hundreds of years:

Melt one pound of beeswax in a double boiler (never, EVER melt wax over an open flame!).  Add one pint of gum turpentine and remove the mixture from the heat, stirring constantly while it cools.  Pour the mixture into a wide-mouth container before it fully hardens, and cover it with an air-tight lid.  Apply the wax to furniture with a soft cloth.  Allow the solvent (turpentine) to evaporate, then polish with a clean cloth.

Recipe taken from: Formulas, Methods, Tips, and Data for Home and Workshop by Kenneth M. Swezey, published by Popular Science Publishing Company, 1969.  Similar recipes also appear in Dick’s Encyclopedia of Practical Receipts (sic) and Processes, originally published in 1863, and in Rodale’s Book of Practical Formulas (1997).

Maplewood with beeswax and carnauba wax
Maplewood with beeswax and carnauba wax polish. Photo by Simon A. Eugster, courtesy of Wikimedia Commons

Both lac bugs and honeybees use wax to construct waterproof protective structures for their larvae.  Humans use wax to waterproof fabric such as canvas sails and raingear.  They also use it to create my favorite textile art, batik.

Indonesian batik
Traditional Indonesian batik, courtesy of Wikimedia Commons


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Let’s take a look at another fascinating property of wax.

Solid but malleable at room temperature, with a low melting point.

Again, honeybees come to mind, crafting those lovely structural honeycombs.

Honeycomb
Honeycomb, photo by Sven Teschke, courtesy of Wikimedia Commons

Humans use this property for things like the art of lost wax casting.  In this technique, wax is sculpted into a form that is used to make a mold, and then the wax is melted away; the hollow mold is then used to cast molten metal (often bronze).

Here’s a book, in case you’re interested in learning more about it:


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Though the function of spermaceti in a sperm whale’s body is poorly understood, the two main competing theories both rely on the wax’s low melting point, which keeps it liquid at the whale’s internal body temperature.  One theory holds that the waxy substance acts as a buoyancy regulator, with the sperm whale able to control the liquidity (and thus the density) of the wax.  The more widely accepted theory is that the spermaceti assists the whale in echolocation.  Either way, something is important enough about spermaceti that a large whale has roughly 500 gallons of it in the spermaceti organ (located at the front part of the head) at any given time.

It’s hard to compete with the coolness of echolocation, but we’re going to give it a try by looking at encaustic painting.  This art form has been around since at least the first century A.D. in Egypt, where it was used to paint “mummy portraits,” or portraits of the dead.  This painting technique uses molten wax mixed with pigment, and is known for enabling rich, textured and luminous color.

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Encaustic Painting, Courtesy of Wikimedia Commons

Here’s a book, in case you’re interested in learning more about this time-honored art form.


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Flammable.

Ah-hah!  I think we might have found a property that only humans use.  At least, I can’t think of any other living creature that purposefully sets things on fire — though I would love to know if there is one.

These days, candles are almost entirely decorative, but it wasn’t so long ago that they served the critical purpose of prolonging the hours in which a person could be productive.

All waxes, which are composed primarily of hydrocarbons (in the form of wax esters), are flammable, though some are better for that purpose than others.  Of the “big four” most commercially important waxes (carnauba wax, candellila wax, beeswax, and paraffin), only beeswax and paraffin are widely used for their flammability.  Though one exception is bayberry wax, which forms a coating on the fruit of the bayberry tree (a.k.a. the wax-myrtle or candle tree, Myrica cerifera) and is used to make the sweet-smelling bayberry candles.

Bayberry Candles
Bayberry candles, with Bayberry leaves, courtesy of CapeCandle.com

So, now we have at least one property of wax that only humans typically use.  But that’s not the end of our exploration of the wonderful world of wax.

Next question: How much wax does the average American consume on a daily basis?

You’re trying to remember the last time you stuck a chunk of wax in your mouth, aren’t you?  You’re thinking, Who eats waxNobody eats wax, unless there’s some wax-eating health food craze, right?

Well, let me put it this way: Think about the last time you ate a nice, shiny apple from the grocery store, or an M&M candy, or a bar of chocolate; the last time you swallowed a pill or used a baking mix or chewed a piece of gum…Chances are, you are eating wax every day, whether you know it or not.  So, how much wax?

To get an idea, let’s take a look at the most widely used food-grade wax in the world.  Carnauba wax (also called Brazil wax, or “the Queen of Waxes”) is extracted from the leaves of the carnauba palm (Copernicia prunifera).  In food products, the wax is used as a glazing agent, a body or mass agent (to add bulk), an acidity regulator, and an anticaking agent.

Here’s a sample of the recommendations of the CODEX Alimentarius (a collection of internationally recognized standards, codes of practice, guidelines, and other recommendations relating to foods, food production, and food safety) regarding limits on how much carnauba wax can be included in food products:

Food Category Maximum allowed amount*
Surface treatment of fresh fruits 400 mg/kg
Processed fruits 400 mg/kg
Surface treatment of fresh vegetables (including mushrooms and fungi, roots and tubers, legumes, and aloe vera), seaweeds, nuts and seeds 400 mg/kg
Cocoa and chocolate products 5000 mg/kg
Imitation product of chocolate and chocolate substitutes 5000 mg/kg
Some confectionery products 5000 mg/kg
Chewing gum 1200 mg/kg
Decorations (for example, fine bakery wares), covers (not fruit) and sweet sauces 4000 mg/kg
Bakery products BPF
Dietary supplements 5000 mg/kg
Flavoured drinks based on water, including “sport”, “energy,” or “electrolyte” drinks 200 mg/kg
Coffee, coffee substitutes, tea, herbal infusions, and other hot drinks of cereal grains, excluding cocoa 200 mg/kg
Ready to eat snacks 200 mg/kg

Source: Carnauba Wax Uses in Food: A Review

So, in things like chocolate and dietary supplements, it’s generally recognized that up to .5% of the food can be wax. According to these guidelines, if you eat, say, one chocolate bar five days a week for a year, about one and a quarter of those bars that year is pure wax.  If you eat an apple every day for a year, you eat the equivalent of about one apple slice’s worth of wax.

However, in the United States, the FDA has categorized carnauba wax as “Generally Recognized as Safe” and there are no specific limits in place as to how much carnauba wax can be included in food.

Nutritionally, the wax is inert — which is why it is so widely used.  Our body does not metabolize it, and it is hypoallergenic.  So, it’s not doing you any harm, but it’s also not doing you any particular good.  Carnauba as a food additive is mostly just there for show — and it’s a fair amount of show.

And that’s just carnauba wax.  Paraffin wax is produced in enormous quantities, and put to very similar uses in food.

Think about that, next time someone asks you a silly question about how much wax you’ve eaten lately.

Next question: What the heck?

There’s one more use of wax that we haven’t talked about yet, that I’m willing to bet is not on your radar: Ceromancy (or carromancy) is the practice of divination by pouring liquid wax into water and interpreting the shapes formed, with the aim of foretelling the future.

Ceromancy, by Lauren Bebry
Ceromancy, by Lauren Bebry (laurenbebry.com)

You might think this practice (along with the many other forms of “-mancy” out there) is just fanciful nonsense, relegated to the realm of superstition and “people who don’t know any better.”  But look a little deeper, and you’ll find a principle that unites humans in their never-ending quest for knowledge about the natural world.  It’s the idea that there are mysterious and complex forces at work in the universe — mysterious and complex, but not unpredictable.  There is an assumption at work here, that there are definite “rules,” and if we could only gain some insight into how they work, we would be able to “see the future” — that is, make predictions about what is going to happen, based on an understanding of how the world works.  That is exactly the foundational axiom of the scientific method: That the laws of nature are complex, but not unknowable, and not random or changeable.  It’s a pretty big assumption, when you stop to think about it.

Luckily for us, and so far at least, it seems to be true.  Our quest for knowledge is not for nothing: when we wake up tomorrow, the universe will likely be operating according to the same rules as it was when we went to sleep the night before.  That’s comforting, isn’t it?

When the human world feels chaotic and unpredictable and overwhelming, it’s nice to look around us at the bigger picture and know that the natural world is build on a rock solid foundation, governed by laws that are the same yesterday, today, and tomorrow.  And are, within at least an important (if not infinite) range, knowable.

Isn’t that so totally awesome?

Bugs

Ailanthus silkmoth

The living creatures that we have categorized as “insects” outnumber all other species put together by…well, a lot.  Frankly, if I were to give you a number, you would pretty much know that I or whoever I had gotten the number from would be mostly guessing about it.  There are (as far as we currently know) around 900,000 distinct species, comprising 70% of all known species (of anything) on Earth — and entomologists estimate that we have only identified about 20% of the insect species that may exist.  Insects are found virtually everywhere, adapted to a staggering variety of climates, habitats, and ecosystems.  Many species are remarkable for the intricate symbiotic relationships they have formed with other species: plants, animals, other insects.  And, of course, humans.

So naturally, I have some questions about bugs.

First question: If there are over 8000 insect species that are known to be edible by humans, why don’t we eat more bugs?

Around the world and throughout the centuries, hundreds of cultures have used thousands of insect species directly as food.  In modern times, at least several of these thousands play an economically important role in direct food production.

Mopane worm on mopane tree (cropped)

Photo: Mopane worm (Gonimbrasia belina) on a mopane tree, by JackyR courtesy of Wikimedia Commons

Take, for example, the mopanie or mopane worm. The mopanie is the larva (caterpillar) of the emperor moth (Gonimbrasia belina), a member of the surprisingly important genus Saturniidae, which we’ll see more of later.  The common name is the result of the larva’s habit of feeding mainly on the mopane tree (Colophospermum mopane).  The tree and the moth are native to southern Africa, and are harvested on the order of hundreds of tons per year as an important source of protein for the region, especially Zimbabwe, Zambia, Botswana, and South Africa.

House cricket cvrcek domaci

Photo: The common house cricket (Acheta domesticus), by Petr Gebelt courtesy of Wikimedia Commons

The common house cricket (Acheta domesticus), native to China but now naturalized to North America and other parts of the world, has for decades in the United States been raised as food for exotic pets.  Now, food-grade cricket farms are becoming the next big thing in cottage or hobby farming.  Not without good reason.  Crickets have a feed-to-food ratio of about 1 to 1, as compared to about 6 to 1 for beef cattle, or 1.5 to 1 for poultry.  In addition, crickets do not produce greenhouse gases, and are easy to breed and raise by just about anyone, with little initial capital investment.  The supply chain currently consists of small cricket farmers selling their stock to businesses specializing in processing the crickets, usually into powder (aka “cricket flour”), which is in turn sold to food producers.  It’s a growing industry that I personally hope will stick around and diversify to include other insect species.

 

Like, for example, mealworms.  Mealworms are the larvae of the mealworm beetle (Tenebrio molitor), and they are also making inroads into human cuisine.  Previously regarded as a pest, since they invade and feed on stored grains, mealworms have transitioned into pet food, and now human food, where they have been a popular food source in Southeast Asia for at least a few decades.

Tenebrio molitor (meelworm)

Photo: Mealworm (Tenebrio molitor), by Rasbak courtesy of Wikimedia commons

In for a penny, in for a pound, that’s what I say.  Once you open the door to insects as food, the world becomes your oyster.  Mixed metaphor, yeah, I know.  But you know what I mean.  If you’re interested in exploring the topic of raising insects for food, I found the little book below to be a handy introduction.  It’s short and doesn’t go into a ton of detail, and doesn’t address the commercial side of farming insects at all. But it gives a good overview, and would definitely allow you to get started raising crickets and mealworms.


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A good starting point for the exploration of the topic of bug-eating around the world is the reprint of an article found in the journal Crop Protection, Volume 11 (Issue 5), pp 395-399, titled “Insects as Human Food” by Gene DeFoliart.  A free excerpt can be found here: Insects as Human Food.

Next questionAre silkworms the only insects that produce usable silk fiber?

No.  Next question.

Just kidding.

The insect that we know as the “silkworm” is the larva (caterpillar) of several species of moth in the genus Saturniidae.  The best known of these is the domesticated silkmoth, Bombyx mori.

Bombyx mori 001

Photo: Bombyx mori larvae on mulberry leaves, by Lilly M courtesy of Wikimedia Commons

This silkworm is native to China and the practice of breeding the moth to produce silk fiber (sericulture) is at least 5000 years old, and may be significantly older.  Bombyx mori is now cultivated worldwide, though the top producers by far are China and India.  Silk fiber is known for its durability and natural shine, both of which have made it a popular textile fiber for in Asia for millennia, and for centuries in the West since its introduction to Europe in around the eleventh century. Famously, the favored food of the silkworm is the white mulberry (Morus alba), which is why this silk is also known as mulberry silk.  So, if you want to cultivate silkworms, you also have to know how to cultivate white mulberry. Can’t have one without the other.

 

Photo credits: (Left) Silk cocoons by Katpatuka, (Right) Raw silk by Armin Kubelbeck, Wikimedia Commons

The silkworm is one of only two cultivated silk-producing moths.  The other is the Ailanthus or eri silk moth (Samia cynthia ricini), native to India, China, Japan, and now naturalized to parts of Thailand.  The favored food of the eri moth is the castor plant and the Ailanthus tree (tree of heaven).

Saturnidae - Samia cynthia

Photo credit: Ailanthus silkmoth (Samia cynthia ricini), by Hectonichus courtesy of Wikimedia Commons

The cocoons of its larvae are harvested to produce eri silk, which is more durable than that of the Bombyx mori, but has a more woolly texture.   Some traditions produce eri silk without killing the caterpillar, by allowing the larva to first leave the cocoon and then unreeling the silk. In northeast India, where the tradition of eri silk originated, the cocoons were harvested mainly for the protein-rich caterpillars, and the silk was then used to weave the traditional chaddar (wrap).

In addition to cultivated silk, there is also wild silk.  For example, Tussar silk (also known as Kosa silk) and Muga silk are produced by several species in the genus Antheraea within the Saturniidae family Native to India, the moths’ cocoons are harvested from wild groves of trees that host the insects. Tussar and Muga silk is widely used in India to make the beautiful traditional sarees and chaddars.

A brief but informative overview of the different types of silk and the silk industry in India can be found on the Central Silk Board of India’s website here.

Tussar silk fabric
Tussar silk fabric (Source: topnews.in)

Many other insect species outside of Saturniidae also produce silk: spiders, crickets, other moths — to name a few.  Some of these are being investigated as possible sources of commercial silk fiber, and it will be interesting to see where this investigation takes us in the future: Spider silk stockings?  Raspy cricket surgical sutures? Who knows?

Next question: What the heck?

It’s inevitable that whenever you’re exploring human invention and the natural world, you’re frequently going to be struck with the question: How did anybody ever think of that?

For example, scale insects.

Scale insects comprise a group of roughly 8000 species of small insects in the superfamily Coccoidea, that are usually plant parasites.  One of their dominant common characteristics is that the females produce a protective waxy coating that makes them looks as if they have scales (hence, the common name).   I can understand how someone would look at that wax and think that it might be useful — and, in fact, it is.  For example, Chinese wax, which is used to manufacture polishes, candles, and other items, is a product of certain species of scale insects native to China and Japan.

Similarly, the lac insect (Kerria lacca) native to India and Asia, produces a resinous protective coating called lac, which is the only known resin of animal origin.  Lac is refined to produce shellac, a type of varnish that has many uses, including as a wood finish and a fruit wax.  This characteristic has made the lac insect the most commercially important of the scale insects, with several thousand tons of shellac produced annually.  Again, I can understand how a person (especially given the long history of use of plant resin) could look at bug resin and think “I can use this for something.”

Kerria-lacca

Photo: Kerria lacca resin on a tree branch, by Jeffry W. Lotz courtesy of Wikimedia Commons

But, how could someone look at a tiny bug living on the roots of herbs, and think to himself, “Hmm, I bet if I squash this and mix it with aluminum and calcium salts, I’ll get a nice strong red dye.”  But that’s in fact what happened (well, something like it, anyway).  There is a group within the scale insects known as the cochineals, and the bodies of these species contain generally high amounts of carminic acid, which is used to make the red dye known as carmine.

Polish cochineal
Life cycle of the Polish cochineal, From Breyn, Johann Philip (1731) Historia naturalis Cocci Radicum Tincttorii quod Polonicum vulgo audit, The Academy of Natural Sciences Library, Philadelphia, United States (Public domain)

The Polish cochineal (Porphyrophora polonica), native to Central Europe and parasitic to primarily the herb knawel (Scleranthus annuus), was for several centuries and through the Middle Ages of great economic importance as a source of red dye.  After the colonization of the Americas, it was largely replaced by the Mexican cochineal (Dactylopius coccus) as the source of carmine.  And yes, there are cochineal farmers still around in Central America today, raising the insects to produce the dye, which is still used as a food coloring and in cosmetics.  If you’re thinking about becoming a cochineal farmer, though, keep in mind that the insect is parasitic to the Opuntia genus (the prickly pear cacti), so you have to live where those grow.  Just FYI.

Cochinel Zapotec nests

Photo: Cultivated cochineal nests on Opuntia, by Oscar Carrizosa courtesy of Wikimedia Commons

And on that note, I’ll wrap up this discussion of the fascinating and ever-changing relationship of humans and bugs.  With this one final thought: of all the bizarre symbiotic relationships that exist between plants and insects, and humans in the mix, the one between the fig wasp and the fig tree strikes me as one of the more awe-inspiring.  The fig wasp and fruit-producing fig tree are completely dependent on each other for the completion of their reproductive cycles.  While humans have managed to breed certain varieties of figs that can be propagated without the wasp, the Smyrna fig remains firmly dependent on the fig wasp.  So, next time you bite into a tasty Smyrna fig, say thanks to the tiny wasp that made it possible.

Here’s a link to a well-done video that talks about the history, nutritional value, and cultivation of fig varieties, including the relationship with the fig wasp.

The Nutritional Value of Fig Wasps

P.S. What about bees?

Yeah, bees are an awesomely big and important topic.  The relationship between bees and humans is very long and very intense.  So long, in fact, that there is at least one cave painting, dating to roughly 6000-8000 B.C., that depicts a human harvesting a beehive (it’s located in Cuevas de la Arana — Spider Caves — in Bicorp, Spain).  We look to bees not only for the important products they make (honey, beeswax, propolis, and royal jelly), but for their even more important role as plant pollinators.  Without bees, many important crops could not be cultivated (or exist at all, in some cases).  Bees will appear many times in this blog, including the next entry, which will be a discussion of the topic of “Wax.”

For now, I will recommend this beautiful and practical book about modern beekeeping and the history of the human relationship with the European honeybee.  It’s a fascinating read, even if you’re not into beekeeping — and if you are, it’s got a lot of great information to get you started.


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Additional References:

(1) Encyclopedia of Insects, by Vincent H. Resh (Ed.) and Ring T. Carde (Ed.).  This would seem like a crazy undertaking to try to catalog all 900,000 species of insect, but if you’re really into learning about the insect world, this is a great reference that highlights some relevant and interesting patterns.  And at almost 1200 pages, it’s got great detail, too.


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(2) I have not read the whole book, but I can tell you that it’s dense and contains more information than the average person would ever want to know about commercially producing insects as human food.  If you’re not the average person, this might be a good choice for you.  Just the fact that there’s a textbook on the subject is pretty cool all by itself.


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(2) Since sericulture (silk cultivation)is mostly practiced in Asia, most of the books out there are by and for agriculturalists in Asia.  Nevertheless, there was a time when the silk industry was thriving in the United States — and who knows, maybe it could be again.  For a short history of silk production in the U.S. see this article.

This is a very robust and detailed manual on sericulture.


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And here’s a lighter version, lacking the depth and detail, but still a useful overview of the practice.


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