On Six Legs by Tom Turpin

 

Many years ago I did media training in preparation for a national tour promoting the O. Orkin Insect Zoo at the Smithsonian National Museum of Natural History. As part of the training I participated in a mock television interview with a former TV anchorman.

I was ready. I had “talking points” and some flea larvae for show and tell.

After the practice interview the trainer pointed out that I had used a term that at least 90 percent of my audience would not recognize. The term was larvae.

He asked rhetorically, “Exactly what are larvae?”

“Larvae are immature insects,” I replied.

“So if larvae are baby insects,” he said, “why not call them that?”

My media trainer then pointed out that if I really wanted to get my message across I would have to use words that general audiences would understand, not scientific jargon. I hadn’t thought about the word larvae as scientific jargon, but I guess it is. Or at least it is not a word used on a regular basis by most people.

So I swallowed my academic pride; and during the multi-city media tour that followed, I talked about baby fleas.

Larvae are found in the lifecycle of holometabolous insects, those that undergo metamorphosis (transformation from immature to adult) in four distinct life stages - egg, larva, pupa and adult. The second, or larval, stage has been described as the eating stage of these insects. It is a good description because eat is mostly what insect larvae do.

Carl Linnaeus first used the word larva, the singular form of larvae, in the mid-1600s. Linnaeus was a Swedish naturalist who developed the system of binomial nomenclature. This is the system of using two words – one for the genus and one for the species – as a scientific name for plants and animals.

Linnaeus recognized that it was difficult to tell what babies of holometabolous insects would be when they became adults. So he selected the Latin term larva that meant mask or ghost for immature forms of these insects.

Linnaeus apparently thought that the form of some baby insects masked what they would be as adults. I agree. To predict what an insect larva will turn out to be is something that has to be learned. And even then it is not always easy to tell one larva from another.

Just as different species of adult insects often resemble each other, so do baby insects. But just like we give groups of adult insects common names, we also give common names to groups of larvae.

Butterfly and moth larvae are called caterpillars. That word is partially based on the Old French chatepilose, or hairy cat. Some caterpillars are indeed hairy such as those that are purported to predict the severity of winter. But other caterpillars, including the tomato hornworm, have a smooth skin.

All caterpillars have an obvious head, six legs and some fleshy bumps that function like legs but are called prolegs.

The “pillar” part of caterpillar is from the Old English word that meant ravager – an apt description of the eating habits of all larvae.

Another type of larvae is the maggot, the immature form of flies that are often found in decomposing and decaying material. Maggots are often described as soft-bodied, legless, headless creatures.

The word maggot probably originated in Old English and meant worm.

That might be the basis for a line from a children’s ditty that has become known as The Hearse Song, “The worms crawl in, the worms crawl out, the worms play pinochle on your snout” – an obvious reference to fly maggots and decomposition.

Larvae of some beetles are called grubs. Beetle grubs have a distinct head with six legs and a general body shape that resembles the letter C. The word grub may have first been used to describe the process of digging in the soil.

Today the word grub might suggest food. Either use of the word grub often applies to many beetle larvae that can be found burrowing in the soil in search of food. The term grub is also sometimes used for larvae of bees and wasps. In this case they don’t look for food, but workers in the nest provide them with the food.

Caterpillar, grub and maggot are all names of immature forms, known scientifically as larvae of holometabolous insects.

Is it OK with you if I just call them baby insects?

The views and opinions expressed in this column are those of the author and not necessarily those of Farm World. Readers with questions or comments for Tom Turpin may write to him in care of this publication.