How one paragraph in the appendix of a 1991 paper put a little ant on the Most Wanted list

Nature Talk
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This is the Ant Web map showing the distribution of Camponotus planatus. The red dots indicate where the ant is considered “introduced” notice anything odd?

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Consider this pair of observations:

https://www.inaturalist.org/observations/87020033

https://www.inaturalist.org/observations/371084114

The first is introduced. The later is not. It’s all a little odd. I suppose a river is a good natural barrier. And a desert. But how did this ant get classified as “introduced” ?

Well, in 1991 one of the few people who cares about this ant wrote a bit about their natural history in FL:

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From the paper EXOTIC ANTS OF THE FLORIDA KEYS by Mark Deyrup

Basically “They Keys” (small islands off the coast of FL) tend to have fauna that are a subset of the fauna of “The Mainland”… but Camponotus planatus broke this rule and so Deyrup reasons that it must be the kind of ant that gets introduced by the presence of humans and therefore isn’t a part of the FL native fauna.

For this reason Camponotus planatus has ended up on all kinds of lists. Lists of ants to watch out for at the border and as imports. Lists used by pest control companies to write descriptions of “what to do about” this ant if you see it.

In the back of everyone’s mind there is Solenopsis invicta, the infamous RIFA.

But can we please back up just a little? What does Camponotus planatus acctualy do? What is the current role of these ants in their environment?

With over 4000 observation this is a very successful ant, and it seems to thrive in outdoor spaces near human dwellings. It is frequently found on flowers and since it’s a hairy ant it is probably a pollinator. It’s normally a tree-nesting ant and it seems to spread with potted plants and palm trees. It can nest in rotting wood and pest control companies try to make it seem omnious to wood structures but I think this is overblown.

The only real issue could be that it “competes with native ants” but it’s not Camponotus planatus doing that it’s the HUMANS who bring in non-native plants, who redesign the landscape and sometimes destroy the places where native (more native???) ants my thrive.

Also… I’m kind of uncomfortable with the whole premise here.

Here is a bit of a hot take: Some of the reasoning about the natural history of this and other ants assumes that populations of ants stay stable for “thousands of years” … unless humans are involved.

I strongly suspect this isn’t the case. That’s my radical thesis. Humans can and often do accelerate changes in ant populations, distribution. But something like a hurricane, or a harsh winter could also reshape ant patterns as well.

Further people have been in FL for “thousands of years” anyways.

Camponotus planatus **did nothing wrong.**

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Photo by mpoinat from this observation.

I’m not above using cute photos to get you to like this ant.

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Two quick notes - I think the reasoning here makes a few big jumps. Deyrup didn’t classify the ant as “invasive” (which might, but does not always, indicate negative impacts - see other forum threads or papers) - just exotic. He’s just hypothesizing on the origin of the ant in Florida, not making any judgments about ecological impacts.

Also, just noting that the photo you posted at the end was published on iNat with an “All Rights Reserved” license, so you probably shouldn’t repost it here, just link.

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Not sure it’s a radical idea that ants can move around the landscape fairly quickly without human assistance.

And it’s funny, but with regards to the paper, I did a survey in Key West in 2018, and did not find a lot of Trichomyrmex destructor, which the paper in 1991 noted as being quite dominant in the area. An invasive ant crash perhaps similar to ones that have happened to Linepithema humile in New Zealand.

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The 1991 paper is cited in the places where this ant has been put on such lists.