Warrior Wasps from Costa Rica

Subject: Evil Looking Wasp

Location: Puerto Viejo, Costa Rica
November 10, 2014 2:23 pm
Hi There,
We are on the Caribbean side of Costa Rica and are planning on moving into a new apartment. These wasps were seen building a nest on one of the poles, and I’m just wondering
a) what are they?
b) is their sting as painful as it looks?
c) how would we exterminate them?
Thanks so much!
Signature: Concerned in Costa Rica

Warrior Wasps build new nest
Warrior Wasps build new nest

Dear Concerned in Costa Rica,
Regarding c):  We do not provide extermination advice.  We thought your wasps looked like Paper Wasps in the genus
Polistes, and following that lead, we came to the Photo Gallery of Eusocial Paper Wasp Genera and Research page where Polistes atterimus (Monteverde, Costa Rica) is described as being “mimics of Synoeca septentrionalis,” so we followed up on that species and genus.  Of the genus, we learned on the same page, the Photo Gallery of Eusocial Paper Wasp Genera and Research, that “These wasps are infamous for their painful stings and ferocious colony defense. When mildly disturbed, they produce an ominous rushing sound, with synchronous rhythm, by rubbing against their corrugated nest paper. Watch out.”  We found an image of Synoeca cyanea on FlickR of the start of a new colony that looks remarkably like your image.  Though we typically do not quote from Wikipedia, we did learn there that members of the genus Synoeca, “Commonly known as warrior wasps or drumming wasps, these insects are known for aggressive behavior, a threat display consisting of multiple insects guarding a nest beating their wings in a synchronized fashion, and an extremely painful sting. Synoeca is one of only three insect types (the others being the bullet ant and the tarantula hawk) to receive a rating of 4 or higher on insect sting pain indices such as the Schmidt sting pain index.”  That takes care of your questions a) and b), and we found further support on the Vespa bicolor page where it states of the genus Synoeca:  “These wasps are known for their aggression, and also for their extremely painful stings (possibly most painful of any social wasps!) Upon any threat near the nest, the workers are able to produce sound by “drumming” on or rubbing against the inner surface of the nest envelope. If the disturbance continues, the wasps rush out and sometimes pursue the intruder for long distances.”

Thank you very much for the information. I have passed it along to my landlord 🙂

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BugMan aka Daniel Marlos has been identifying bugs since 1999. WhatsThatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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