Antroducing: The mystery of the missing carpenter ants (Camponotus ligniperda)

When we went to the Carpathian mountains with its extensive forests, it was 'carpenter ants' that we were particularly hoping to find. This name is actually not for a single species, but rather the extremely large Camponotus genus, consisting of over a 1000 species, most of which carving out their nests in soft or decaying wood, instead of underground in the dirt like most ants do.

Another characteristic is that carpenter ants typically have workers of different sizes, the largest ones called majors. It takes some serious muscle to chew through wood and these Camponotus majors are often among the biggest ants you can find in a country.

And you'll find them deep in the woods. This is actually kind of noteworthy, because even though trees always attract many different types of ants for the amount of food they provide, there aren't that many ants able to cope with the lack of warm sunshine in the dense forests of colder climates.

Camponotus country.

Of course, we already had queen Brünhild, a Camponotus ligniperda, sitting on a pile of brood at home, but there are quite a few other species in Romania and Kittenmancer definitely wouldn't object to some more ants of the 'big and shiny' category. Also because these ants have an extremely long growth cycle and Brünhild wasn't going to get her first workers until spring next year.

So how do you catch ants that are hiding inside a tree? It's harder than to dig them out from under a rock, that's for sure. But on the other hand, the carpenter ants prefer rotten logs and tree stumps so that at least makes them easier to locate. Armed with a screwdriver, Kittenmancer and I spend quite a big of time the first few days taking apart decaying wood, but with little success. We were hoping for queens that flew out a few months earlier and were now sitting on their first brood in shallow tunnels dug by various wood-boring grubs. However, all we found were beetles, centipedes and said grubs... oh, and typically for Romania, we found a ton of human garbage too.

The Carabus auratus, a ferocious hunter of snails, worms and grubs.

No words for this...

As explained in the previous post, we figured we were just too high up in the mountains where it was too cold. It could be that there were actually Camponotus ants here, but they were probably few and only obvious during their summer activity. We were going to be more successful lower in the valley.

As our several-hour hike progressed, we indeed started to encounter encouraging signs like sawdust-like piles next to rotting wood and even an abandoned nest in a big half-gone stump which the ants turned into a swiss cheese. There probably wasn't enough wood remaining for adequate shelter.

We forgot to take a picture, but this is what it looked like, only less...

We poked more dead logs and trunks, but still no ants to be seen, getting quite desperate, until we bumped into a lone Camponotus ligniperda major crossing the hiking trail. We were getting warmer! However, as we saw no other ants, this was probably a lost forager, unable to guide us back to her nest.

Eventually we reached the meadow, yet still no success. So we had lunch and dug out a bunch more of Myrmica ruginodis as a bit of a consolation colony for the lack of Camponotus. Our feet were tired though and so we headed back after admiring the little mountain river for a bit.

Idyllic wetness down the path.

There was just one more spot that I wanted to check out. I had poked it a bit earlier, but didn't see any ants. However, it was such a perfect spot (a small log, half-buried in low vegetation right next to the path and exposed to direct sunlight), that it warranted a more thorough inspection on our way back.

Usually we took a careful approach, not needlessly destroying too much potential real estate for future carpenter ants, but now, out of time, I took out a big piece right in the middle, uncovering a few Camponotus ligniperda workers halfway into the start of their hibernation. Jackpot!

I felt then certain that we were going to catch this colony. This was only a small log for the colony to hide in, not a cubic meter of dead tree still halfway in the ground. And the next peeled off layer exposed their queen and a few more workers inside a small chamber with brood. It was clear that this was still a young colony, only about a year old with less than fifty workers. However, as we cracked the nest open further, trying to find the queen (she had immediately bolted), we realized that the Camponotus were not the only tenants of this log.

Their neighbour was a much older, much larger and much angrier colony of Myrmicas (probably the same species we had been running into the whole week). These inhabited mostly the bottom half of the log, embedded in the dirt, and had probably not fully realized the Camponotus had moved into their empty attic (scouts going missing, hallways getting blockaded, that sort of stuff).

But now the carpenters' nest was cracked wide open and their neighbours were pouring out of the lower parts of the log, looking for a fight. Of course even the smallest Camponotus workers are three times larger than a Myrmica, but they were outnumbered at least fifty-to-one. On top of that, a single Myrmica worker could kill even the largest opponents with just one well-aimed sting. So we now had an emergency on our hands, because the queen was still right in the middle of this mess.

Luckily we had many hands available.

We tear off the top half of the log and put it in the middle of the road. The brood, easily distinguished by its characteristic yellow color is immediately collected. Quickly dismantling the layers of rotting wood, we race the furious Myrmicas, trying to rescue as many Camponotus as we can. At least these big ants are sturdy enough to be picked up with your fingers without harming them. When the queen is finally located, she has a small enemy worker stuck on her hindleg. Kittenmancer, by now an expert in dislodging Myrmica biters, takes care of her and we all take a deep breath of relief.

We then continue to mop up as many of remaining carpenters as we can, though we find ourself quickly running out of places to put them in. Having several of our most convenient boxes already occupied with the Myrmica colony we collected earlier, we even had to improvise with a hastily emptied-out Tic Tac box.

No more workers in sight, we put the log back neatly for the Myrmica's to reclaim it. We realize that we probably saved this Camponotus colony, because it is unlikely that they could have held out against their much more aggressive neighbours for another few years, heavily competing for food and living space. Heading back to our hotel and still a long walk ahead of us, Kittenmancer personally carries the box containing queen Ruxandra (now named after her cousin) and a big part of her colony.

Moving the colony when we finally got home a few days later.

Later that day the Camponotus were surprisingly easy to reunite into a single test tube, ready to go to their home in the Netherlands in only a few more days. By then I was also getting slightly anxious to get home. But it wasn't after we would catch one more final ant colony, one that would require all our ant wrangling skills to keep in check. Read about them in my next post!