May 19, 2025
Hey hey hey! Today was, like yesterday and the day before, a fantastic day. We worked on two projects today, the first being a pitfall trap experiment to assess nitrogen limitation in arthropods in the canopies versus the forest (underlying assumption: canopies have less nitrogen. Hypothesis: arthropods of the canopies will exhibit more signs of nitrogen limitation (be more attracted to nitrogen-rich fluid (human pee) than arthropods of the forest floor.) In the afternoon, we began an experiment with Cecropia trees. This was exciting for me, because I am the ant man. These trees, like the Bull’s Horn Acacia mentioned earlier this week, are protected by a colony of Azteca family ants living inside them (except Bull’s Horns have Pseudomyrmex ants in them.) The experiment considered whether young Cecropias found other ways to protect themselves from herbivores before they were inhabited by ants, so the experiment didn’t directly involve ants, but that didn’t stop us from studying how the colony moves about the tree.
The first tree we found was inhabited by a whole colony, and it was so cool to see them swarm to protect the tree and to see the tree’s structure to provide a home for them. The second tree we found, after a long search, was much younger and had only one inhabitant: the queen. She was laying larvae, and the tree was not yet colonized, so we sued it for our experiment and called it day there.
However, throughout the day, we saw many cool ants. In the morning, doing the nitrogen-limitation pee experiment (where we peed in tubes to see if arthropods would be more attracted to our nitrogen-rich pee compared to water,) we saw a leafcutter ant colony that must have been 30-40 feet long across the trail. SUPER cool. Right next to the colony (or right above,) there was a Bull’s Horn Acacia Tree coexisting with the Leafcutter colony. We decided to run a fun experiment by putting a leafcutter soldier on the acacia tree to see what would happen. Unfortunately, while attempting to rouse the ants who lived on the tree, the leafcutter soldier fell off so the experiment was cut short. We got to see it run away from one of the Pseudomyrmex guard ants though, which was pretty cool.
In the afternoon, when looking for a cecropia tree, we naturally ran into the cecropia ant inhabitants. Our afternoon experiment will test whether or not young (not colonized by ants) cecropia trees will develop alternate (chemical, physical) defenses to herbivorous predators before they are colonized by ants and benefit from that defense. When we happened upon an adult cecropia tree, we got to see how they swarm out when it falls, and how the tree has evolved a hollow structure inside of it for the ants to live. The structure is an akin to the ants having high-rise apartments, because that tree is tall! Cecropia ants all fall under the Azteca family, and I think we saw Azteca alfari based on the looks. After we saw the big cecropia tree & colony, we set out to find the young uncolonized tree. While we searched, we happened upon two more really cool ant phenomena. The first, we saw a young leafcutter ant colony. We could tell it was young for two reasons: a) the colony entrances were small. there were multiple, indicating an age greater than one year, but still relatively small and therefore young. b) the ants were bicolored (red head and abdomen and a darker thorax.) Dr. Solomon did some inconclusive research as to why leafcutter ants may be discolored, but he discovered that ants were bicolored when the colony was young, which is how I know that colony is young! After the young colony, we saw an ant I hadn’t seen yet or even researched: theCamponotus sericeiventris, or Carpenter ant (but it directly translates to “Golden butt” ant, which is more fitting.) After we saw these two ants, we found the young cecropia tree, which was supposed to be uncolonized, but the one we found had one singular inhabitant: the queen! It was super cool to see her working in the little tree before her colony and her tree grew (her colony and tree did not grow because we cut it down unfortunately.) Overall, it was another fun and interesting day to be the ant man, and I know tomorrow will be even better as we are to spend the afternoon investigating leafcutter ant colonies! What a treat!
Ttylxox,
Sam
Images:
Me with my Pee tubes for the nitrogen limitation experiment:
Huge leafcutter ant colony
Bull’s Horn Acacia directly next to/ on top of huge leafcutter colony
Colonized Cecropia tree filleted open
Bicolored leafcutter ant (Image from https://leafcuttingants.com/forum/viewtopic.php?t=531&start=10)
Golden butt carpenter ant (Image taken by Dr. Solomon) (I know it doesn’t look gold, the gold part has mostly fallen off)
Young Cecropia tree filleted open showing only the queen inhabitant
