About 10 years ago during the last forest tent caterpillar outbreak in Prince George, Dezene Huber’s four-year-old son was playing outside.
Huber, who is an insect ecologist at the University of Northern British Columbia (UNBC), saw his son tossing the caterpillars into puddles and to his surprise, Huber noticed the caterpillars could swim.
“The little hairs on their body kept them afloat, and then they did a little nice kick and moved along like Olympic swimmers which surprised us,” said Huber.
He took a video of the swimming caterpillars and posted it on a research site hoping to investigate the phenomenon further one day, but it ended up on the back burner as he carried on in other research areas that seemed more serious.
However, the subject came up during a recent conversation with his colleague Amanda Roe, who works with the Canadian Forest Service Agency in Sault Ste. Marie and raises caterpillars to use in research.
“She said maybe we should think about doing this with other caterpillars as well and I thought that is a great idea,” explained Huber.
He then put out a call on social media asking for anyone who has videos of caterpillars swimming to send them in with a description of where and when the video was taken, as well as what kind of plant the caterpillar was found on so they could try and identify what species it is and begin to figure out what, why and how caterpillars can swim.
The two researchers also paired up Akito Kawahara from the University of Florida, who was investigating the same thing with his students but had also moved on to other things.
“The reality, of course, is that there’s no real practical reason for doing this type of thing,” noted Huber.
“There are some interesting evolutionary questions there and just overall interesting natural history. We saw this as an opportunity to explore and see if there are interesting trends we might notice which could spur on other research in other areas.”
He said he doesn’t expect there to be any particular practical pest management application to finding out why and how caterpillars can swim but at the same time you never know where research can lead.
“We are curious about nature and sometimes you never know where these things spin-off too in terms of practical applications as well,” said Huber.
“You never know and if there is something to be learned and if we have the opportunity to learn it that’s great and if social media can help us to get some interesting data to analyze then that is great too.”
Huber said that although caterpillars are terrestrial, they still encounter water, and therefore would need the ability to swim.
“It seems a bit esoteric, but when you think about it some caterpillars especially some living on trees could fall off and could fall into water,” said Huber.
“So having this ability to maneuver in the water, in one way or another, and survive that incident means they would pass that ability onto their progeny and then you end up with swimming caterpillars.”
Anyone who sends in a video to assist with this research will be listed as a co-author if it is ever published.
Huber is asking anyone who has videos of caterpillars or other larva swimming or sinking to email huber@unbc.ca and include where the video was taken, the date it was taken, and who made the video as well as the species or what kind of plant it was found on.
“It is interesting natural history, and we hope we can figure something out and add to our understanding of caterpillar ecology and evolution on a broader scale.”
In terms of when Prince George and the central interior will be hit with another forest tent caterpillar and moth outbreak, Huber says it’s likely still quite a few years away.
He said what happens is the population continually builds until the point of collapse – once they reach the capacity in the ecosystem they become susceptible to predators, parasites, and diseases and the population begins to crash.
“Right after the crash for a few years you wouldn’t see them anywhere, they’d still be a few out there but you’d have to look hard because they would be the last survivors of the diseases, starvation, and predation,” said Huber.
“Everyone asks me when are we going to get another outbreak, I don’t know, but I have started seeing a few more of them around. It is not large numbers yet, but it probably means that in a few years the populations will start to build up again.”
He said usually people start to notice them in large numbers for a year or two before it turns into a massive caterpillar explosion.
🧵And guess what? It turns out that they can swim – pretty well actually. Here's a video that I made of one swimming and another leisurely floating around. pic.twitter.com/LuOoSwbKpW
— Dezene Huber 🇺🇦 (@docdez) June 17, 2022
