Are Painted Ladies (Vanessa cardui) introduced in North America?

When you click on the taxa for Painted Lady butterflies (Vanessa cardui), there is a banner at the top saying native to North America. But then when you click on the Status tab, the status is listed as introduced for most US states, parts of Canada and Mexico, and most other jurisdictions in North America. This made me curious. Does anyone know if they are really considered introduced in North America? I know Painted Ladies are migrants/ strays in colder parts of North America. But I had never heard they were considered non-native to America. (I am not flagging the taxa yet because I don’t know the answer myself. I am hoping someone else will!)

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They are not introduced in North America as a whole, that would be an incorrect listing. They may be considered introduced in some specific states however, although I wouldn’t know which ones, if any.

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I think the status for the larger part is set to native if it’s native anywhere within, i.e. if a species is native to (anywhere in) North America, it would be set to native for it but then to “introduced” for any area underneath where it’s not. It makes it impossible to update for normal users, but I think curators have a way to mass-assign “introduced” to places.

pisum also wrote a tool to see the list as the website itself can’t display more than 100: https://jumear.github.io/stirfry/iNat_taxon_est_means.html?taxon_id=48548

Vanessa cardui is a common mail-order species for caterpillars used for educational purposes or adults for butterfly-release events (e.g., weddings). I can imagine this lends itself to anthropomorphic range expansions. Vanessa cardui is naturally very widespread, and I am not sure if there is any rigorous determination of where they occur naturally and where they have been introduced (though just because I don’t know about it, doesn’t mean it doesn’t exist).

As a side note to the general audience: please do not mail-order butterflies or other insects (e.g., ladybugs, mantids, etc.) even where these species are native. This can lead to the spread of disease and muddying of local ecotypes, among other issues.

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I’ve read in NC, there are years when they are abundant and others when they are nearly absent and it has to do with migration mostly. We also have the American Lady, Vanessa virginiensis, and I’ve seen them both. They differ in the number of spots on the wings but can be difficult to tell apart. I suspect there may be a good number of misidentified records for both species in this area.

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They’re considered native in North America and they’re highly migratory, so I’m surprised they’d be considered non-native anywhere here except maybe in the far western states where they’re replaced by the closely related and frustratingly similar West Coast Lady.

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I reviewed several sources and changed the iNat NC status to Native. Based on the language in the range descriptions, I think many other states may need the establishment value changed. (e.g. https://www.butterfliesandmoths.org/species/Vanessa-cardui)

Were these marked as Introduced by mistake or was someone being very strict about the possibility of human introduction?

I’m a bit confused here: Folks are saying that the Painted Lady is native to most of North America, but here in Southern Africa we have the very same species (Vanessa cardui) which I’m almost certain is native to this subcontinent as well. So is this a paleotypic species with widely disjunct populations across continents, or do I have my facts wrong?

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The species is simply extremely widespread. It is native to all continents except Antarctica and South America. In fact, one of its old common names is “The Cosmopolitan”.

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Interesting.

Quite curious that its not to be found in South America? As it seems to thrive in forest habitats here in South Africa

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They are probably scared of crossing the Darien Gap

The similar close relative Vanessa carye, the western painted lady, occurs in South America.

Seems someone has labeled them as introduced to Arkansas. I’d like to see the reasoning for this.

That list is perplexing. Says it’s native to only a handful of states and they’re not even close together. Native to Michigan, North Carolina, Georgia and Texas. But for the states between those select four it’s labeled introduced.

While marked Native to NC (my edit), someone has marked it introduced to every county in NC and a bunch of smaller places in the state. So all the NC observations still say Introduced.

I flagged the taxon for review. I haven’t seen any information that would indicate it’s introduced over these wide areas.

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I went through and fixed about 10 checklists in my area until the exclamation mark disappeared for Central New Mexico. I’ve seen no evidence of anthropogenic introductions of this species here.

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There’s also red admirals, mourning cloaks (=camberwell beauty), and monarchs in North America which are species additionally shared with Eurasia. They are considered native as well.

I suspect our populations in the US are supplemented by released ones, but it must be a very small fraction of their occurrence here.

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And that’s why I think this is a curator issue. There are about 7500 checklists that probably say Introduced. I don’t who or why all these places were marked but it was thorough.

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What happened is that when a species is marked as introduced in a large area such as North America, that introduced marker cascades down to all place checklists within North America. A curator is able to fix this.

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