“Biodiversity” is a pretty all-encompassing term. Many people use it when talking about worldwide biodiversity, i.e. all of the different animals on the planet, from parrots to parrotfish. But the term also applies to smaller groups – in this case, much smaller. We can see tremendous biodiversity just by looking at one tiny subset of a single family of insects: Formicidae – better known as ants.
Leafcutter ants in action. Image by Kathy & sam.
Dr. Ted Schultz shows off some of the live fungus-farming ant colonies in the NMNH AntLab. Image by Jim DiLoreto.
As I’ve mentioned before, I used to be an intern at the Smithsonian’s National Museum of Natural History, or NMNH. I worked for Dr. Ted Schultz in the AntLab, in the Entomology department, for 8 months in 2015-16. Ted’s research was all about fungus-farming ants like leafcutters, which are symbiotic with a certain fungus species that they farm for food. A good chunk of the lab space was dedicated to live ant colonies, and part of my intern duties included preparing and dishing out leaves, fruit, and other materials that the ants could use to grow their fungus gardens (and also trying not to get bitten; leafcutter soldier ants are big and have powerful jaws).
The main part of my work, though, was to help visiting researcher Dr. Jackson Helms with his research on the ants of the Guyana Shield, a region of northern South America that covers Guyana, Suriname, French Guiana, and parts of Venezuela, Colombia, and Brazil. I was the specimen photographer for the project, which meant that for about 3 months, all I did was take photo after photo of preserved ant specimens that Jackson had mounted on pins. As far as I know, there weren’t any new species discovered in that project. But I did produce the first ever images of particularly oddly-shaped ant called Dolichoderus inpai!
My photos of the Dolichoderus inpai are the first known images of the species.
To photograph such small specimens, I used this really cool microphotography setup. Focal lengths are hair-thin when you’re photographing something so small at such a close distance, so I focused using an extremely precise knob. First I would position the pinned specimen using a little lump of clay. Then I adjusted the scope attached to the camera lens so it was focused on the part of the ant that was closest to the lens, pressed a button, and then refocused on the farthest part of the ant. All of this was hooked up to a computer with software that recorded the top and bottom focal lengths, and took photos at every single point between those points, in order to get every single bit of the specimen in focus. Then the software automatically compiled every one of those stacked images into a single clear photo where everything was in focus. I still had to go in and clean up the fuzzy bits in Photoshop later (another few months of work), plus record all the metadata and upload everything to the online database AntWeb, but this software-scope-camera setup allowed me to photograph 5, 6, sometimes 7 specimens per day. I photographed their heads, their profiles, and their backs, as well as the labels that were also on the pins.
This Lauensis is a type specimen, so I had to be even more careful than usual while photographing it.
Over the summer of 2015, I photographed over 200 ant species from the Guyana Shield. There was definitely a learning curve – I had to redo several sets of photos because they were too close, and on one particularly clumsy day near the beginning, I knocked off the heads of 3 specimens in a row. But I got better and better, and towards the end of my internship, I was even asked to photograph a few type specimens, one of which was over 100 years old! Type specimens are preserved specimens that are used as the defining example of that species, and they’re extremely valuable and important. I did not knock off the heads of any of those ants.
There are around 12,000 known ant species from around the world, and some scientists estimate that there may be as many as 22,000 species. I was photographing a mere 200 or so, all from the same relatively small region of South America. But even in that tiny subset, I saw so much variety and biodiversity.
Let’s look at jaws first:
Atta laevigata is better known as a leafcutter ant, a type of fungus farmer. This particular specimen is a soldier.
Eciton hamatum is a sort of army ant. Those big curvy mandibles are used to carry loot back home after raiding parties.
Anochetus horridus is a trap-jaw ant. They lock their mandibles open, and when a smaller creature triggers the sensitive hairs, the jaw snaps shut around the prey.
Thaumatomyrmex atrox is a specialist millipede hunter.
All of those ants were from separate genera, but you can still find a lot of variety within the same genus (in this case, Cephalotes):
Cephalotes atratus is much larger and spinier than other ants in the same genus.
Cephalotes persimilius has flat translucent ridges on its sides instead of spines.
You can even find variety in members of the same species! Ants live in colonies, and many types of ants have developed specialties such as workers or soldiers. Here’s a worker and a soldier from an as-yet unnamed Camponotus species (and my personal favorite ant):
Worker
Soldier
Then, of course, you get ones that are just plain weird like these guys:
The awesomely named Gigantiops destructor has absolutely enormous eyes relative to body size.
Daceton armigerum is another trap-jaw ant, with sensitive hairs that trigger the ant to snap its mandibles shut.
Ants are pretty cool, and they really help illustrate biodiversity up close. Not that you shouldn’t focus on global biodiversity – but take some time to consider microcosms of biodiversity too.