Book Review: Underbug

Termites exist at the intersection of biology, chemistry, ecology, engineering, and perhaps even philosophy. In Underbug: An Obsessive Tale of Termites and Technology, author Lisa Margonelli masterfully weaves all of these elements together, and then some. She manages to remain in that sweet spot between total participation in the story, and complete detachment, never overtaking the spotlight of her subjects, both insectian and human, but still revealing the personal impacts of where her investigations took her. She maintains empathy with the reader while taking them on a globe-trotting journey.

Underbug has more to say about humanity than you would expect in a book ostensibly about insects, let alone insects we consider economic pests. This is about where curiosity and imagination can take you. It ventures from the microscopic world of termite gut fauna to the megascopic, landscape-writing engineering of millions of diminutive members of a termite colony. How are they so successful? How can we harness their power to digest cellulose and use it to manufacture “grassoline?” What lessons exist for how to reclaim an abandoned mine and turn it back to its native grandeur?

It may be cliché to say that a book has something for everyone, but this one truly does, provided you are prone to a fascination with science, or relish contemplating the planet and our own place on it.

The book is divided into six parts, each one set off by a black-and-white illustration that gives the impression, appropriately, of a woodcut print (they are linoleum block prints by Thomas Shahan). The dust jacket has intentional holes in it, as if the book has already been “digested” by its very subject. How perfect. Margonelli manages to have a reverence for both termites and science, but never comes off as preaching or dogmatic. There is humor here and there, and the prose are descriptive enough to put you right in the center of things.

As a failed academic myself, I felt overwhelmed occasionally by the mathematics, genetics, and technological aspects of the stories (there are several), but remained captivated by the human characters and, of course, the mysteries of the insects.

Margonelli ultimately questions the accepted scientific course of the abstraction of natural processes, whether it has its limits, or if it is even a potential failing of our own species. Are we too attached to the idea that every other species, every habitat, serve us first, to justify its existence?

Without giving too much away, the conclusions reached are, as one might expect, inconclusive; for termites exist at the intersection of the known, the unknown, and the unknowable. Sometimes the biggest question for a researcher or engineer is when to give up.

Underbug was published in 2018, by Scientific American / Farrar, Straus and Giroux, New York. It is 303 pages, including notes and index. This is as much an adventure book as it is a revealing glimpse into what defines science in the twenty-first century. Highly recommended.

Predator and Prey: Ants versus Termites

My neighborhood walk in Colorado Springs the other day, March 25, was like strolling through living confetti at some points. All the local termite colonies were launching swarms of winged males and potential queens (alates as scientists call them). The frail creatures were not ignored by other animals, either, especially ants. Closer inspection of the swarms revealed three species of ants preying on them.

Alate subterranean termites (Reticulitermes sp.) swarming

Termite swarms are not an indication of the impending collapse of your home or any other wooden structure. Yet, that is the first thought that enters the mind of the average person witnessing the spectacle. Such is the power of advertising for pest control companies. Now, a termite swarm inside your home should probably be cause for alarm. Outdoors, subterranean termites like these Reticulitermes sp. are vital to the recycling of decaying wood. They nest in the soil, as their common name suggests, and forage for wood and other dry cellulose in contact with the soil.

The synchronous nature of termite swarms is a marvel. All colonies in a given area need to liberate their reproductive castes at the same time in order to prevent inbreeding, but I have no idea how they "decide" when to do this. The day before we had snow and high winds. The alates issue from the tiniest of cracks in the soil, like toothpaste from the tube, the better to avoid easy detection. Eventually, enough of the insects appear that their gauzy wings reflect the sun and give away their presence. Soldier termites, and workers, too, escort them out and see them off.

Alate termites with workers and soldier (center) escorts

Hundreds, if not thousands, of winged termites begin filling the air. Few will survive the alert eyes and hungry mouths of birds, lizards, and other predators. The early season timing of swarms may in fact be tuned to precede the emergence of reptiles and the arrival of migrant birds. Ants, on the other hand, are already on the prowl.

Worker Formica sp. ant carrying termite prey

Both ants and termites are social insects, so it is fitting they would be deadly enemies and, one would think, well-matched foes. Watching one swarm happen on the edge of a driveway, I began noticing the appearance of worker ants, Formica sp., crossing the driveway. Eventually I saw one toting a winged termite back to the nest. The ant's nest. More ants followed suit.

Pavement ants (Tetramorium caespitum) killing alate termite (bottom) and worker termite (top)

Turning my attention back to where the termites were emerging, I noticed something even more frightening. Tiny "pavement ants," Tetramorium sp., were killing both alates and worker termites right at the termite nest opening. Whereas Formica ants are a bit larger than the termites, the pavement ants were smaller than their prey. How they avoided the menacing jaws of the soldier termites confounds me.

Formica ants near the entrance to their nest, with prey

Just up the street I noticed heavy ant activity originating at the base of a brick-and-mortar mailbox pillar. These were Formica pallidefulva ants, but appeared larger than the other ones I saw previously. It soon became apparent that they were also taking part in the Great Termite Massacre of 2017. Most of them were carrying wingless alates, though.

Ants (Formica pallidefulva) with termite prey

Alate termites, once paired, shed their wings easily. Both pairs of wings have a weak spot that allows the termites to break them off so they can quickly seek cover. The male ("king") termite follows on the heels of his mate (queen) as they form a two-car train in search of a potential nest site. They must do so quickly if they are to avoid the marauding ants.

Dealate queen with her mate trailing her in a "train"

Whether the honey pot ants were taking dealate (wingless reproductives) termites, or just seizing winged individuals and breaking off their wings, remains a mystery. They are certainly easier to transport without those cumbersome wings.

Worker Formica sp. ant carrying termite prey

As I turned the corner to go home, I caught sight of yet another ant, possibly Formica podzolica. It, too, was carrying a defeated termite. The ant seemed at least somewhat disoriented, and I eventually lost track of it in the thick grass at the edge of the curb.

So, termites are both integral to keeping soils fertile with their decomposition activities, and also a bounty for many other organisms that depend on them for food when other insect life is less plentiful. Ants are the lion kings and wolf packs of the macroscopic landscape, keeping termites and other insects from overrunning the planet. The ants are not immune, though, and in my next post we see them on the other end of the predator-prey equation.

Note: Special thanks to James C. Trager for identification of the ant species.

Termite Swarms

It is, was, or will be termite swarming time across much of North America. Contrary to popular “knowledge,” we do have termites here in Colorado, at least below 7,000 feet elevation. Our most abundant species is the Arid-land Subterranean Termite, Reticulitermes tibialis. Back on the morning of May 24, I happened upon a colony that was liberating its “alates,” winged reproductive termites that will mate with members of other colonies and begin their own new colonies.

Subterranean termites actually nest in the soil, consuming wood and other sources of cellulose that are buried in the soil or in contact with the soil. Turning back a board out in the shortgrass prairie here in Colorado Springs is likely to uncover foraging termites that quickly seek shelter back in their underground tunnels.

A typical termite colony consists of a “king” and “queen,” a male and female pair that founded the colony and bond for life. That life can be a decade or more for the queen. Her sole mission is to lay eggs, and she is a bit of a bloated creature, her abdominal segments distended. Still, she can move around rather freely, in contrast to the huge, immobile queens of some tropical termite species that exist trapped in a “royal cell” defended by soldier termites.

Soldier termite

Subterranean termite colonies have soldiers, too, with large, rectangular heads and oversized jaws they can use to dispatch ants, the chief predators of termites. Most of the colony is made up of a “worker” caste that does the foraging, underground tunnel- and above-ground tube-construction, tends the queen and newly-minted immature termites. All the young termites in the colony are workers, but have the potential to become soldiers or reproductives. In situations where a queen dies, or becomes separated from part of the colony, some workers can metamorphose into supplementary reproductives capable of laying eggs themselves within their parent colony.

Once each year, a mature colony launches a swarm of winged male and female termites that goes in search of mates in hopes of starting new colonies. Arid-land Subterranean Termites typically swarm from January to March at elevations below 4,000 feet, and in June or July above that elevation. The alates I witnessed were issuing from imperceptible cracks in the soil, like toothpaste oozing from the tube. Check out the video below:

Termite swarms are like a buffet to insectivores, and it was only a matter of minutes before tiny ants set upon the lethargic alates, carting them off by the bushel to feed their own ant larvae in some subterranean nest. Birds, amphibians, lizards, spiders, and countless predatory insects feast on the living confetti.

Ant carrying off alate termite

Those female individuals that do survive are mostly wind-blown across the landscape, hoping to land in the vicinity of an unrelated colony that is also swarming. The female sheds her wings and emits a pheromone (chemical scent) that attracts males. Once a suitable mate appears, they mate and begin searching for a nesting site. The pair creates a small chamber underground or beneath a stone or other object, and she begins laying eggs.

Alate termite with hind wings stuck together

How do you tell winged termites from winged ants? Winged termites have two pairs of wings of equal length, whereas ants have the front wings much larger than the hind wings. Ants have long, elbowed antennae, while termites have shorter antennae with segments of equal length. Ants have the body clearly divided into three sections: head, thorax, and abdomen. Winged termites have those divisions much less obvious. The thorax and abdomen seem to merge seamlessly in termites.

Pair of winged ants, Crematogaster sp.

Subterranean termites are not large insects. Even the alates of the Arid-land species measure only 10 millimeters from nose to wingtip. Soldiers are a mere 3.5-4.5 millimeters. This species occurs throughout the intermountain west of the U.S., eastward to Missouri, Arkansas, and Texas, south to Mexico. Other species of Reticulitermes range in other parts of North America.

A termite swarm outdoors, away from your own home, is a spectacle to behold. An indoor swarm….not so much. Still, to suddenly witness an enormous population of normally unseen animals erupting from the landscape is simply stunning. It helps to know that, in nature, termites are valuable decomposers that turn and aerate the soil while breaking down cellulose into nutrients now available to other living organisms.

Notes: Fairly recently (2007), termites became reclassified. Once they were members of their own order, the Isoptera. Today they are recognized essentially as “social cockroaches,” lumped with roaches in the order Blattodea.

Termites, unlike carpenter ants that merely chew cavities in wood to make nesting space, actually do eat wood. They can do this thanks to a gut fauna of microbes that efficiently break down cellulose. The bacteria, archaea, and protozoans exist only inside of termites, and are acquired by young termites when they consume fresh fecal material of adult termites, or are fed regurgitated, partially-digested food by worker termites.

Sources: Cranshaw, Whitney and Boris Kondratieff. 1995. Bagging Big Bugs. Golden, Colorado: Fulcrum Publishing. 324 pp.
Helfer, Jacques R. 1972. How to Know the Grasshoppers, Cockroaches, and Their Allies (2nd edition). Dubuque, Iowa: Wm. C. Brown Company Publishers. 359 pp.
Noll, Kenneth. “NSF Termite Project,” Noll Lab.
”Termites Are Cockroaches After All,” Natural History Museum (London) News.