A few weeks ago I was introduced to the Dissection Scope, which it turns out can be used for a significantly less macabre purpose than dissection: observation! Kitted out with two flexible flashlight-arms, any subject put under this machine can be lit up for a proper photoshoot. The difficulty in this arises from my wanting to photograph live ants, which I hope you can imagine are quite squirmy and not to mention incredibly small (5-6mm for C. varians, and 8-11mm for P. gracilis).
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| [1] A photo of me, the author, focusing in on a Cephalotes varians worker. Also pictured is the dissection scope, from which ant photos were taken by putting my phone up to one of the binocular eyepieces. |
One thing I had going for me was the nigh indestructibility of Cephalotes varians, as that “turtle” nickname is not for show. Cephalotes as a genus are renowned for their thick armor and flat bodies, making them veritable walking tanks in the ant world even despite their size. The armor on Cephalotes varians in particular is so strong that we in the lab have observed them being entirely unaffected by the power bites of our other, much larger species Pseudomyrmex gracilis, the slender (and vicious) twig ant. Because of their outstanding armor, Cephalotes have been observed to exhibit a behavior called “bulldozing.” As the name implies, the ants march (they prefer to meander rather than move very quickly, all that armor comes at a cost of speed) their way through hordes of other ants, ignoring all manner of stinging, spraying and biting attacks, often to steal resources from those other ants (thanks to our senior thesis student for finding this cool bit of info!). This was all convenient for me because it meant I could safely pin them under a rubber band (loosely, they’re not invincible) across their abdomen (the back part of a bug) to then put under the dissection scope.
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| [2] A Cephalotes varians worker, the second of two I photographed. This worker was quite relaxed, standing fairly still for the camera, letting me get some great shots (as great as my phone camera would permit). |
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| [3] Another side profile, more clearly showing the head and forelegs. Her right antenna is extended towards the lens, making it blurry, poking out from under the overhang in which it can be tucked into. You can also see the segmented “feet,” called tarsi, with which she is grabbing the rubber band. |
Under the scope, we can see these awesome ants in as much detail as my phone was willing to capture. Note the almost bedazzled appearance of their carapace, something invisible to the naked eye. The wide heads and overall-flat body allow the ant to “glide” when it falls from the trees it normally inhabits (“gliding” ant is another of its nicknames). You may think that all this armor I’ve been raving about would make it more resilient to the impact it might experience should it fall out of a tree (although our ants live in Florida mangroves, so the only floor they would fall into would be water, meaning certain doom) but that’s actually just because of its size. Ants are so small that the impact force they experience when falling from any height is negligible. We in the lab find this convenient because it means if they fall or we brush them off our hands, they are completely unperturbed.
As clearly seen in Figure 3, the head of a worker provides overhangs which can be used to house and protect the ant’s antennae. These side-mounted antennae are unique to Cephalotes. The most unique aspect of Cephalotes are their wide, flat heads. These ants are specialized to be all-in on defense, having evolved for their heads to be just about the sizes of their nest entrances. Soldiers especially have thick, disk-shaped heads that work as perfect doors to block these nest entrances from all manner of intruders.
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| [4] Top-down view, look how sparkly! Besides the abdomen, which is covered, you can see the overall structure of the ant. You can just barely see her eyes and the tips of her mandibles, and her antennae are fully outstretched. Her front two legs are tucked under her head, but the structure of her middle legs are easier to see. |
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| [5] Here, I held the slide upside down to take a look at the underside of her head, showing that her jaws were much larger than I had thought, just more tucked away under her head. The jaws are layered, with several parts that can reach out to drink any liquid food (the preferred form for this species) they come across. |
Our other species, Pseudomyrmex gracilis, are a mysterious species with very little literary information on them. They are also not native to Florida, coming from Central and South America, which could be part of why they are understudied. What we do know is that these ants are known to be fairly aggressive, possess and use stingers, and are capable of hunting their own food. These ants are also not as heavily armored as our turtle ants and much wider around, so I was a bit concerned about injuring them when trapping them under a rubber band. Instead, I opted to trap them inside a small vial, and thankfully I was able to focus in on my subject even through the round plastic walls. However, these photos were not as crystal-clear as I would have liked, so I turned to the singular dead gracilis worker in our lab’s possession and photographed it as well.
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| [6] Underside view of Pseudomyrmex gracilis. Many differences include sharper tarsi, larger eyes, longer antennae on the top of the head, larger mandibles, and an overall more “slender” body, hence the nickname. |
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| [7] Here we can see the same ant arching her abdomen, a behavior characteristic of laying pheromones. What pheromones? Not sure! But it is an interesting behavior that we have been observing in our 1-on-1 aggression experiments, so it was neat to see it up close. |
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| [8] A top-down (and blurry) photo of the same ant. The antennae are more easily seen here. |
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| [9] Side profile of the dead ant. One note is that these ants are much hairier and much less ‘bedazzled’ compared to Cephalotes varians. |
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| [10] Flipped view of [9], here the subject is stuck on the end of a paintbrush. The face is much more easily seen here, showing the mandibles, antennae and eyes in greater detail. |
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| [11] Close-up of the abdomen, showing its long hairs. These caught me off guard, as they are very difficult to see with the naked eye but highly visible when magnified. While I could not find any true consensus, it seems that hair on insects can be for sensory or heat-regulation purposes, among many other possible things! |
The dissection scope has been exceedingly useful for my photographic endeavors, much more than a magnifying glass or even a traditional compound microscope would have been. Despite working with these ants the whole semester, and even looking up magnified photos of them, there were still so many details I would never have noticed before taking my own photos. I still cannot imagine how professional macro-photographers get the incredible photos, especially in-focus ones, that they do. I hope this has provided an enlightening look into the two kinds of wonderful little creatures we are hosting in the HMC Bee (Ant) Lab this year, and that when you read the blog posts of my lab partners you can remember exactly how awesome our ants really look!
Further Reading/Viewing:
https://www.antwiki.org/wiki/Pseudomyrmex_gracilis The one major source on Pseudomyrmex gracilis.
https://youtu.be/f7KSfjv4Oq0?si=cQVT50j9OjPBhm4e&t=157 More on how size affects evolution.
https://www.alexanderwild.com/Ants/Taxonomic-List-of-Ant-Genera/Cephalotes For excellent macrophotography of ants.
Media Credits:
All images created by the author.
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