As a pre-teen with a fondness for Nancy Drew mysteries, I developed a taste for hidden messages. I’d see them everywhere, written in puffy clouds or in raindrops sluicing down a windshield. But binomial species names were my favorite, filled with secrets. Why people didn’t like these pompous-sounding appellations, I couldn’t understand. After all, who doesn’t love a good clue?
What we call the binomial system of nomenclature was devised in 1758 by a Swedish botanist named Carrolus Linnaeus. Linnaeus (also known as Karl von Linné) realized we needed a naming system that allowed scientists from around the world to agree on which organism they were discussing. The use of common names was too confusing because the names changed according to time, location, language, and culture. He was looking for universal common ground.
We call these “Latin” names because they are based on Latin grammatical forms, but they are traditionally some combination of Latin and Greek. Lately, however, we see names that sound more modern. Our common enemy, Varroa destructor, is a good example. Although “destructor” has a modern ring, it actually derives from the Latin word “destruere” meaning “deconstruct.” Yes, varroa mites deconstruct countless honey bee colonies each year.
More than just a name
In addition to providing a name, the Linnaeus system arranges living organisms into what we believe is their lineage, demonstrating who is related to whom. Let’s look at Apis mellifera more closely.
Below is the scientific classification of the western honey bees as it now stands according to the Integrated Taxonomic Information System:
- Kingdom: Animalia
- Subkingdom: Bilateria
- Infrakingdom: Prostomia
- Superphylum: Ecdysozoa
- Phylum: Arthropoda
- Subphylum: Hexapoda
- Class: Insecta
- Subclass: Pterygota
- Infraclass: Neoptera
- Superorder: Holometabola
- Order: Hymenoptera
- Suborder: Apocrita
- Infraorder: Aculeata
- Superfamily: Apoidea
- Family: Apidae
- Subfamily: Apinae
- Tribe: Apini
- Genus: Apis
- Subgenus: Apis
- Species: A. mellifera
In certain parts of the world, subspecies can be found. Examples include:
- A.m. carnica
- A.m. caucasia
- A.m. ligustica
- A.m. mellifera
- A.m. capensis
- A.m. scutellata
Notice the superfamily Apoidea. It contains the apoid wasps, sphecoid wasps, and bees. This is the last place where bees and some wasps appear in a single classification, showing how closely they are related. In other words, a scientific name isn’t just a name but a method of explaining relatedness.
Back when Linnaeus wrote his book, “Systema Naturae,” there were only two kingdoms. Since everything was either a plant or an animal, deciding how to classify something could be tricky. Plants are more closely related to other plants than to animals, and they are more closely related to some plants than others. So when you discovered a new plant, you simply slotted it into the best place.
That worked until you had something like a fungus, microsporidian, bacterium, or even a simple euglena that can eat and swim like an animal and produce food like a plant. Generations of scientists were forced to pick a kingdom even when neither was quite right. Although Linnaeus would probably be shocked, today we have five kingdoms, which makes classification a bit easier.
The basic binomial system
The basic naming system has a few easy-to-use rules:
- The higher-order classifications are written in straight text, but the genus, species, and subspecies (if any) are written in italics, as in Apis mellifera mellifera, the European black bee. Handwritten names require underlining.
- The genus name (the noun) is always capitalized and the species name (the adjective) is never capitalized, hence Bombus ternarious, the tricolored bumble bee.
- After the first use of the genus name in an article, the genus can be abbreviated. For example, A. mellifera, V. destructor, or G. mellonella (the greater wax moth). Or, as shown above, you can abbreviate both the genus and species names. Be careful, though. If you write about Andrena prunorum and Apis mellifera in the same article, you shouldn’t abbreviate the genus unless the reference is clear.
- Sometimes the specific name is followed by the namer’s name, such as Apis mellifera Linneaus or Apis cerana Fabricius.
A tautonym is a binomial name where the genus and species names are the same. Examples include Mephitis mephitis (the common North American skunk), Bison bison (the American bison), and the lovely hydrozoan Velella velella (by-the-wind-sailor). In case you were wondering, triple tautonyms happen, too. For example, the common black rat is Rattus rattus rattus.
When a scientific name is also used as a common name, you can write the common name without any special format. Whether or not this usage is acceptable depends on the publication. Here at ABJ, you can use varroa as a common name, no capital letter or italics needed.
The rules applied to Linnaeus, too
The binomial system of nomenclature comes with a rule book of sorts. One rule says that if multiple names are assigned to a single organism, the first published name will become the accepted one. Linnaeus himself was confounded by this problem after he erroneously named — wait for it — Apis mellifera.
In 1758, he named the honey bee A. mellifera meaning honey-carrier. Three years later, when he realized that honey bees don’t carry honey, they make honey from nectar, he tried to change the name to Apis mellifica, meaning honey-maker. By then, his system had been adopted by many scientific groups and they would not allow him to change the bee’s name. Oddly, you will still see Apis mellifica in some older publications. Such a name is known as a synonym.
Some species have many synonyms, either because more than one person named species that turned out to be identical, or because a shift occurred in our understanding of the relationships between species. When DNA analysis became commonplace, many species changed names because we were able to understand more about their origins and relationships.
Shape-shifting the taxonomy
Despite the logic behind updated names, people get frustrated with the number of changes. One of the first Latin names I learned was Toxicodendren radicans, poison ivy. I was in primary school, so this was a proud moment. Older guides called it Rhus radicans, but I liked the new name because I could relate to the “toxic” part.
I don’t know how many years passed, but one day I saw it written in a new book as Rhus radicans again. What? My ego took a hit. Then I saw it as Rhus toxicodendron, and I was miffed. I wanted order and reliability. So I decided to read more about these plants and became nonplussed when I learned all those toxic plants — poison ivy, poison oak, and poison sumac — were in the Anacardiaceae family along with mangoes and cashews. It was decades before I gathered the nerve to swallow those things, sure they would kill me.
I sympathize with folks frustrated by name changes. But the shifts become less jarring when we realize the changes are meant to give order to things that aren’t necessarily orderly. As we embrace new research tools, we can see what we couldn’t using morphology alone. So what was once Varroa jacobsoni is now V. destructor and last year’s Nosema is this year’s Vairimorpha.
Some species shift back and forth as researchers debate where they belong. Right now, the pruinose squash bee is bouncing around like a tennis ball, depending on who’s writing. Some days it’s Peponapis pruinosa and some days it’s Eucera pruinosa. Good thing the bee doesn’t care.
Born in the USA
Beekeepers get testy about the type of bees they keep. Oftentimes, a proud beekeeper will take a photo of his charges and send it to iNaturalist, identifying them as, say, Apis mellifera carnica. This quickly gets “downgraded” by one of the identifiers (often me, I’m afraid) to Apis mellifera, making for angry beekeepers.
But there are good reasons for being conservative. The taxonomists who oversee the bee section of iNaturalist are adamant that no pure ….