Planet of the Bugs: Evolution and the Rise of Insects (37 page)

3
. If big dinosaurs had survived the end-Cretaceous asteroid impact, and they, instead of us, had evolved big brains and consciousness (and dinosaur egos), perhaps they would call the last sixty-five million years the Age of Dinosaur Civilization.

4
. This simple method of panning for insect gold was pioneered and perfected by the renowned entomologist Lubomir Masner, and it works remarkably well for sampling micro-Hymenoptera (microscopic wasps).

5
. Since I wrote this chapter, I have returned to Ecuador five more times and continued to work on my elusive new wasp. My description of the new genus and species was published during May 2012 in the
International Journal of Tropical Insect Research
, so the organism now has a formal scientific name:
Napo townsendi
, the genus named after the province of Ecuador where it lives, and the species named after Andrew Townsend, my student who first collected the wasp. In May 2012, by lucky coincidence I happened to be in Ecuador at the same time my research paper was published, and I had the exciting experience of being the first person to see a living, newly named
Napo townsendi
. I should mention that in June 2010, my col
league Dr. Nina Zitani was the first to spot living, although unnamed, specimens perching on some trailside leaves.

We have discovered that the males, while still scarce, can predictably be found perching on leaves of
Dendrophorbium
tree seedlings. I’ve hypothesized that the male wasps are using these select leaves as platforms for attracting females. During May 2012 and 2013, along with my colleague Dr. Will Robinson from Casper College and our student research assistants, Delina Barbosa and Andy Kulikowski, I learned that the male
Napo
wasps demonstrate a sequence of predictable behaviors that suggest they might be using sex pheromones to mark leaves and attract distant, rare females. Will discovered that the males show remarkable fidelity to particular leaves, often spending several days on the same leaf or returning to the same one after briefly flying away. On sunny mornings, the males groom themselves, first rubbing their hind legs over the tips of their abdomens then over their wings’ upper and lower surfaces. When the males are at rest, early in the morning or late in the afternoon, they normally fold their wings over their bodies, but immediately after grooming, they hold their wings outward at 45° angles. We’ve hypothesized that this wing posture is a calling behavior that ventilates pheromones rubbed onto the wing surface. Later in the summer of 2012, I sent a preserved male specimen to Dr. Donald Quicke, a world expert on the glands of parasitic wasps, at Imperial College London. He dissected the abdomen and documented that there is indeed a unique set of glands along its back sides, near the tip, exactly where we predicted.

Female
Napo
wasps remain comparatively rare and elusive. In four years, we have briefly spotted only ten, while they were mating. We are continuing to study
Napo townsendi
, documenting them with photographs and video, but I think we are making good progress in understanding how these rare and widely dispersed tiny insects manage to find each other in the forest.

6
. Imagobionts are so named because their adult host insects are technically known as the imago stage. Based on amber fossils, we know that they had evolved by at least fifty million years ago, making their origin and diversification one of the Cenozoic era’s notable events.

7
. At our current pace, it could take another five hundred years just to identify, name, and catalog all the other living species. Clearly we don’t have the luxury of taking that long. If we can count the digits of the number π to more than one billion decimal places, why can’t we get on with the task of naming the several million species that reside with us? If we don’t, we’ll have no way to communicate information about these organisms and no way to associate new information with the same creatures.

8
. You don’t need to travel that far. If you are patient and spend a lot of time looking, you can find new microscopic insects living in your own back yard. I have found them in mine.

POSTSCRIPT

1
. We have already devised remote-sensing space probes able to discover the conditions suitable for life. One of these probes, the
Galileo
spacecraft, made a pass near earth before heading to its final destination—Jupiter—and its instruments were directed toward our planet. From a distant vantage point in outer space, through spectral analysis and with infrared photography, we were able to detect three clear indications of life on earth. The first, the presence of an oxygen-rich atmosphere, is attributed entirely to the presence of photosynthetic life, for we don’t know of any nonliving processes that would allow oxygen to accumulate to such exceptional levels (near 21 percent of the earth’s atmosphere). It also hints at the possibility of oxygen-respiring animals, which stabilize oxygen production (by consumption) near those levels. The second, widespread light-absorption in a particular wavelength, is attributed to only one substance that we know of: the pigment chlorophyll in plants. The third, trace amounts of atmospheric methane, is particularly interesting because this gas is unstable in the presence of oxygen: it oxidizes into carbon dioxide and water. Its persistence indicates steady methane production by living organisms: by bacteria, social insects, and, lately, humans.

2
. Haldane is quoted as saying this in Evelyn G. Hutchinson, “Homage to Santa Rosalia, or Why Are There So Many Kinds of Animals?”
American Naturalist
93 (1959): 146. However, Hutchinson refers to it as “a story, possibly apocryphal.” Haldane, in his book
What is Life?
, made a similar statement: “The Creator would appear as endowed with a passion for stars, on the one hand, and for beetles on the other” (John Burdon Sanderson Haldane,
What is Life? The Layman’s View of Nature
[London: L. Drummond, 1949], 258).

Suggested Reading

CHAPTER 1: THE BUGGY PLANET

Berenbaum, May R.
Bugs in the System: Insects and Their Impact on Human Affairs
. Reading, MA: Addison-Wesley, 1995.

Marshall, Stephen A.
Insects, Their Natural History and Diversity
. Buffalo, NY: Firefly Books, 2006.

Moffett, Mark W.
The High Frontier: Exploring the Tropical Rainforest Canopy
. Cambridge, MA: Harvard University Press, 1993.

Wilson, Edward O.
The Diversity of Life
. New York: W. W. Norton, 1992.

Wilson, Edward O., and Frances M. Peter, eds.
Biodiversity
. Washington, DC: National Academy Press, 1988.

CHAPTER 2: RISE OF THE ARTHROPODS

Barnes, Robert D.
Invertebrate Zoology
. Philadelphia: W. B. Saunders, 1974.

Brandt, Danita S. “Ecdysial Efficiency and Evolutionary Efficacy among Marine Arthropods: Implications for Trilobite Survivorship,”
Alcheringa
26 (2002): 399–421.

Brandt, Danita S., D. L. Meyer, and P. B. Lask. “
Isotelus
(Trilobita) ‘Hunting Burrow’ from Upper Ordovician Strata, Ohio,”
Journal of Paleontology
69 (1995): 1079–83.

Erwin, Douglas, James Valentine, and D. Jablonski. “The Origin of Animal Body Plans,”
Scientific American
85 (1997): 126–37.

Gore, R., and O. L. Mazzatenta. “Explosion of Life: The Cambrian Period,”
National Geographic
184 (1993): 120–36.

Gradstein, F. M., and J. G. Ogg. “Geologic Time Scale 2004—Why, How, and Where Next!”
Lethaia
37 (2004): 175–81.

Hoffman, P. F., A. J. Kaufamn, G. P. Halverson, and D. P. Schrag. “A Neoproterozoic Snowball Earth,”
Science
281 (1998): 1342–46.

Lageson, David R., and Darwin R. Spearing.
Roadside Geology of Wyoming
. Missoula, MT: Mountain Press, 1988.

Lane, Nick.
Oxygen, the Molecule That Made the World
. Oxford: Oxford University Press, 2002.

Lipps, J. H., and P. W. Signor, eds.
Origin and Early Evolution of the Metazoa
. New York: Plenum Press, 1992.

CHAPTER 3: SILURIAN LANDFALL

Beerbower, J. R., J. A. Boy, W. A. DiMichele, R. A. Gastaldo, R. Hook, N. Hotton III, T. L. Phillips, S. E. Scheckler, and W. A. Shear. “Paleozoic Terrestrial Ecosystems.” In
Terrestrial Ecosystems through Time
, edited by A. K. Behrensmeyer, J. D. Damuth, W. A. DiMichele, R. Potts, H. D. Sues, and S. L. Wing, 205–35. Chicago: University of Chicago Press, 1992.

Gensel, P. G., and H. N. Andrews. “The Evolution of Early Land Plants.”
American Scientist
75 (1987): 478–89.

Gensel, P. G., and D. Edwards.
Plants Invade the Land
. New York: Columbia University Press, 2001.

Jeram, A. J., P. A. Selden, and D. Edwards. “Land Animals in the Silurian: Arachnids and Myriapods from Shropshire, England.”
Science
250 (1990): 658–61.

Lucking, R., S. Huhndorf, D. H. Pfister, E. R. Plata, and H. T. Lumbscyh. “Fungi Evolved Right on Track.”
Mycologia
101 (2009): 810–22.

Wellman, C. H., P. L. Osterloff, and U. Mohiuddin. “Fragments of the Earliest Land Plants.”
Nature
425 (2003): 282–85.

CHAPTER 4: SIX FEET UNDER THE MOSS

Cressler, W. L. III. “Evidence of the Earliest Known Wildfires.”
Palaeos
16 (2001): 171–74.

Edwards, D., P. A. Seldon, J. B. Richardson, and L. Axe. “Coprolites as Evidence for Plant-Animal Interactions in Siluro-Devonian Terrestrial Ecosystems.”
Nature
377 (1995): 329–31.

Engel, Michael S., and David A. Grimaldi. “New Light Shed on the Oldest Insect.”
Nature
427 (2004): 627–30.

Gaunt, M. W., and M. A. Miles. “An Insect Molecular Clock Dates the Origin of Insects and Accords with Paleontological and Biogeographic Landmarks.”
Molecular Biology and Evolution
19 (2002): 748–61.

Gensel, P. G., and H. N. Andrews.
Plant Life in the Devonian
. New York: Praeger Press, 1984.

Gorb, S. N. “Uncovering Insect Stickiness: Structure and Properties of Hairy Attachment Devices.”
American Entomologist
51 (2005): 31–35.

Greenslade, Penelope. “Collembola (Springtails).” in
The Insects of Australia
, vol. 1, edited by Ian D. Naumann, 252–64. Carlton: Melbourne University Press, 1991.

Grimaldi, David, and Michael S. Engel.
Evolution of the Insects
. New York: Cambridge University Press, 2005.

Labandeira, Conrad C., B. S. Beall, and F. M. Hueber. “Early Insect Diversification: Evidence from a Lower Devonian Bristletail from Quebec.”
Science
242 (1988): 913–16.

Rasnitsyn, Alexandr, and Donald L. J. Quicke.
History of the Insects
. Dordrecht: Kluwer Academic Publishers, 2010.

Retallack, G. J. “Early Forest Soils and Their Role in Devonian Global Change.”
Science
276 (1997): 583–85.

Rice, C. M. “A Devonian Auriferous Hot Spring System, Rhynie, Scotland.”
Journal of the Geological Society
152 (1995): 229–50.

Shear, W. A. “Early Land Animals in North America: Evidence from Devonian Age Arthropods from Gilboa, New York.”
Science
224 (1984): 492–94.

Westenberg, K., and J. Blair. “The Rise of Life on Earth: From Fins to Feet.”
National Geographic
195 (1999): 114–27.

Wheeler, Ward C., Michael Whiting, Quentin D. Wheeler, and James M. Carpenter. “The Phylogeny of Extant Hexapod Orders.”
Cladistics
17 (2001): 113–69.

CHAPTER 5: DANCING ON AIR

Berner, R. A., and D. E. Canfield. “A New Model for Atmospheric Oxygen over Phanerozoic Time.”
American Journal of Science
289 (1989): 333–61.

Béthoux, O. “The Earliest Beetle Identified.”
Journal of Paleontology
83 (2009): 931–37.

Brauckmann, C., B. Brauckmann, and E. Gröning. “The Stratigraphic Position of the Oldest Known Pterygota (Insecta, Carboniferous, Namurian).”
Annals of the Geological Society of Belgium
117 (1996): 47–56.

Carpenter, Frank M. “Adaptations among Paleozoic Insects.”
Proceedings of the First North American Paleontological Convention (1969)
1 (1971): 1236–51.

Carpenter, Frank M. “Arthropoda: Superclass Hexapoda.” In
Treatise on Invertebrate Paleontology
, edited by R. L. Kaesler, 1–655. Boulder, CO: Geological Society of America, 1992.

Djernaes, Marie, Klaus-Dieter Klass, Mike D. Picker, and Jakob Damgaard. “Phylogeny of Cockroaches (Insecta, Dictyoptera, Blattodea), with Placement of Aberrant Taxa and Exploration of Out-Group Sampling.”
Systematic Entomology
37 (2012): 65–83.

Dudley, R.
The Biomechanics of Insect Flight: Form, Function, and Evolution
. Princeton, NJ: Princeton University Press, 2000.

Hasenfuss, I. “A Possible Evolutionary Pathway to Insect Flight Starting from Lepismatid Organization.”
Journal of Zoological Systematics and Evolutionary Research
40 (2002): 65–81.

Kukalová-Peck, J. “New Carboniferous Diplura, Monura, and Thysanura, the Hexapod Ground Plan, and the Role of Thoracic Lobes in the Origin of Wings (Insecta).”
Canadian Journal of Zoology
65 (1987): 2327–45.