Missouri confirms invasive Asian needle ant, and experts warn its sting can trigger anaphylaxis

The Asian needle ant, an invasive species now confirmed in Missouri, is easy to underestimate because its sting can cause serious allergic reactions in some people, including anaphylaxis.

Human activity, especially the movement of firewood and other wood-rich materials, can help invasive species spread into new places.

What happened?

A Springfield resident's photo of a "weird" ant posted to iNaturalist helped lead to Missouri's first confirmed identification of the Asian needle ant, according to KCUR.

Emily Althoff, an urban entomologist with MU Extension and Lincoln University, said that she had already been tracking the species to see whether it was approaching Missouri before she collected a specimen herself.

"I felt like a little detective," Althoff said, per KCUR. "I also was able to confirm this particular insect because the second I picked one up, I got stung. So, I can confirm that the sting is not pleasant."

Despite its small size, the species has a few traits that can help with identification. It is commonly found in wooded, wood-heavy places and can be recognized by its stinger and lighter reddish-brown legs.

Experts do not believe the ant is necessarily new to Missouri, only that this is the first time it has been positively identified in the state.

Why does it matter?

Althoff warned that people who are allergic to bee or wasp stings may also be vulnerable to dangerous reactions from the Asian needle ant because all three belong to the same insect order, Hymenoptera.

That means an encounter outdoors could quickly become a medical emergency for some Missourians.

The ant's impact is not limited to people: it can push out native ants, occupy nesting sites used by pollinators, and lower termite populations.

While that last effect may sound beneficial at first, termites play an important role in breaking down dead wood in forests.

"If there are no termites, then now we have this pile of dead wood in our forests, potentially enhancing risk for forest fires," Althoff said. "And so, termites actually are really beneficial when they're not in our houses."

What can I do?

Althoff said people should be especially careful when handling wood, brush, or other materials that have been left undisturbed.

"To keep yourself physically safe, don't move firewood," she said, per KCUR. "Just try to make sure that you're not grabbing something that you can't see the underside of."

Moving firewood can increase the chances of getting stung and help carry invasive insects into new habitats.

If you think you have found an Asian needle ant, do not crush it. Althoff said that makes positive identification impossible.

Instead, put the insect in a container that can go in the freezer, then reach out to the Missouri Department of Conservation so experts can determine how widespread the species may be.

"We came in here to see if we'd ever had any reports of it prior. We did not," Althoff said. "It's been a fascinating introduction to how invasive species identification works."

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