Breadcrumb

Beetle Mania

Looking at biodiversity through beetles

“Biodiversity can’t be maintained by protecting a few species in a zoo, or by preserving greenbelts or national parks. To function properly, nature needs more room than that. It can maintain itself, however, without human expense, without zookeepers, park rangers, foresters or gene banks. All it needs is to be left alone.” — Donella Meadows

“We’re losing biodiversity globally at an alarming rate, and we need a cornucopia of different plants and animals, for the planet’s health and our own.” — Diane Ackerman

“Biodiversity is our most valuable but least appreciated resource." — E.O. Wilson

Not too many years ago, country parsons (pastors, preachers, ministers) would sometimes also be naturalists, exploring the abundance of life surrounding their parsonage in an effort to more fully appreciate the creations of their divinity. Charles Darwin was on that path.

He graduated from Christ College in Cambridge University, but his passion was collecting beetles. He felt that as an Anglican country parson he would need to work just one day a week, and then have the other six to collect his beloved beetles. However, before he was ordained, one of Darwin’s professors at Christ College, John Stevens Henslow, received a request from the British Admiralty, inquiring whether Henslow would join a upcoming voyage of the HMS Beagle to survey and map the coast of South America, serving as both ship’s naturalist and dining companion to the ship’s captain, Robert Fitzroy.

Henslow was a professor, an Anglican Priest, husband, father, botanist, geologist, naturalist, beetle collector, and Darwin’s mentor. Fitzroy was from a line of British sea captains, but within that lineage one of those previous captains had suffered a mental collapse and committed suicide.

Due the British class system, ship’s captains did not fraternize or dine with their crew, even their officers. Fitzroy, concerned that due to that isolation, he too might suffer the mental collapse of his ancestor, and so requested to the Admiralty that he be allowed to bring along someone who was his social peer, someone he could dine with and talk to and perhaps help keep his mind on an even keel. 

Henslow was very tempted. The opportunity to survey the plants, geology, and beetles of South America was an unparalleled chance to make his mark as a world class scientist. But his commitments to his family and his professorship at Christ College would not allow him to be gone for years, and perhaps never return (traveling by sailing ship in the early 19th century, without most of the navigation aids available today, offered no guarantees of a safe return).

Henslow saw a raw talent in Darwin, and in his letter to the Admiralty declining the offer to go to sea on the Beagle, he recommended Charles Darwin take his place. The rest as they say, is history. Darwin and Fitzroy both safely returned to England after a five year voyage.

Over a century later another British Scientist, J.B.S. Haldane was giving a lecture to an audience that included an Anglican Bishop. After the lecture, the Bishop asked Haldane what from his research “could then be inferred about the mind of the Creator from the works of His Creation?” Haldane’s reply was "An inordinate fondness for beetles." Haldane’s quip wasn’t (just) mocking the Bishop; beetles comprise one fourth of all known species of animals, and many more beetles exist that have yet to be described and catalogued by science. My own foray in to beetle diversity was an outcome of my interest in cataloging the range of insects that fringe-toed lizards consume as prey. I started by collecting the lizards’ scat and seeing under a microscope the multitude of insect exoskeleton fragments that comprised that scat. Going from a that microscopic jigsaw puzzle to identifying what species were being eaten by the lizards required surveying the diversity of insects that lived on the dunes. 

One outcome of that effort was a publication in 2000 that described the biodiversity of one family of beetles, darkling beetles (Tenebrionidae – “Tenebs”), that lived on the remaining sand dunes of the Coachella Valley. Darkling beetles fill the “clean-up crew” niche, eating the seeds and plant fragments blown on to the dunes. In moister climates that same niche is typically filled by bacteria and fungi. Darkling beetles comprise the dominant (in terms of sheer numbers of species) animal in deserts around the world. Years ago, when I visited the Namib Desert in southwestern Africa, I saw nearly a dozen Teneb species inhabiting the sand dunes. Not only did they clean up the dunes, but they also captured precious scant water, in the form of fog that rolled across the dunes almost every morning. Some beetles dug shallow trenches and then collected fog-born moisture that was captured on the trench edge. Others did head-stands on the dunes and the fog collected on their bodies and eventually dripped into their mouths. Then those beetles were chased, captured, and eaten by dune lizards, giving those lizards a critical source of water in a desert where it otherwise almost never rains. 

On the Coachella Valley sand dunes, stretching from Snow Creek to Indio, I found 30 different species of darkling beetles. I also found one species that had never been collected, described, or named. Unfortunately, I could not find anyone with the time and interest to go through the tedious process of naming it as a new species. That was until one day I met an entomologist from France, staying at the Boyd Deep Canyon Desert Research Station just south of Palm Desert, who specialized on darkling beetle taxonomy. He asked me if I had come across any new beetles and I handed him half a dozen of my mystery beetle. A year later I received an envelope from him with his recent paper – naming the beetle after me: Edrotes barrowsi. Just one of the 30 Tenebs that somehow divide up this dune system so that each has carved out a unique place to exist and thrive.

I often try to put that in perspective by asking folks to imagine a forest that provided habitat for 30 species of warblers, or a lake where one could fine 30 species of nesting ducks. In either example 30 species would be 5 to 10 times more than the number of warblers or ducks would actually occupy their respective habitats. If you did find that many ducks or warblers in one place there would be no question that it was a special place worthy of protection. As far as I know, to date no one has found any other location anywhere with that level of darkling beetle biodiversity.

Then there is the level of lizard biodiversity we have found here, in a region extending from Joshua Tree National Park to the northern third of Anza Borrego Desert State Park. With at least 33 lizard species, there are more lizard species here than any other similar sized area in North America. This is not “just an empty desert." 

For some, biodiversity is synonymous with “nature," but it is much more than that. Biodiversity indicates an understanding of the relative number of species within a defined area. Of course, we may never know the actual number of insects or bacteria or fungi within that defined area. But, using vascular plants, reptiles, birds, and beetles we can rank areas in terms of their biodiversity within a particular biological province. There is little meaning in comparing biodiversity between a tropical forest, a grassland, and a desert. The value come when we compare regions within a biological province, within a desert, within grasslands, within deciduous forests. Places with accumulations of species (higher biodiversity) can indicate where species have found refugia during past climate changes, and where they may survive if we get control of this current climate shift.  With such comparisons we can prioritize and focus conservation efforts to ensure we do not leave an impoverished planet to future generations.

"In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught." — Baba Dioum, 1968