Tags
Australia, caste, Costa Rica, hymenoptera, meliponi, photography, stinger, stingless bees, Tetragonisca, trigona
An Aussie Trigona (carbonaria, I think) on a paperbark (Melaleuca sp)
The Trigona is a large genus of stingless bees found in Australia, the Indo Pacific and throughout the Neotropics. For those curious about taxonomy, they are in the tribe Meliponi, which is in the family Apidae, which is the same family that contains both bumblebees and honeybees. An illustrious heritage indeed!
Their common name “the stingless bees” is a little unfair…the familiar stinger of many Hymenopterans (including bees, ants, and wasps) is a modified ovipositor, so only females can sting. This is true of all Hymenopterans, but it is not very helpful for some, like the honeybee, that form large social aggregations of mostly females, all with ready stingers.
There are other types of bees that do not sting, though. For example, most of the Andrenidae (a family of solitary bees) can not sting.
Anyway, the Australian Trigona spp. are very tiny and adorable.
Trigona carbonaria on an invasive Cirsium thistle
But I was chuffed to also find some stingless bees (I think representatives of the genus Tetragonisca) in Costa Rica. Accustomed to the gentle nature of the Aussie species, I knelt incautiously close to the nest to get a photo.
I only managed to get the one photo…sorry it’s not very good! You can see that they are already on the move.
The stingless bees of Costa Rica form colonies with unique spouts (like this one) near the base of large trees. A certain proportion of the colony is soldiers, which sit around on the outside looking for photographers to harass.
Their response was instantaneous. They swarmed all over me. Jim, our lead professor, exclaimed in some alarm to see me covered in crawling bees. He caught my arm and pulled me away from their tree and we went running into the woods.
He helped me swat some off and he said, “Are you okay? I can’t tell if you’re laughing or crying.”
“I–I’ve never seen anything so pathetic!” I gasped between helpless laughter. I was crying because I was laughing so hard.
It’s true that the Neotropical stingless bees are incredibly aggro, but that’s just it, they can’t sting! They can bite, however, as I eventually found out. They take their sweet time about it though. I’ve never seen such an inefficient attempt at attack. And they wasted an awful lot of time chewing on my hair. (I am sure they are much more intimidating to their normal predators.)
They are, however, also the most persistent attackers I’ve ever had (except for that annoying tourist). Forty minutes later, I was still pulling buzzing, angry bees out of my hair.
A few weeks after the trip was over, Jim sent me an article titled: “A morphologically specialized soldier caste improves colony defense in a neotropical eusocial bee“, by Grüter et al in PNAS last year.
Here is an actual quote from the paper: the soldier caste gives the bees a “sophisticated defense system”.
A figure from the paper showing how different the soldier (right) and worker (left) are. from Gruter et al, 2011
I also love the last line of their paper: “It also serves as a reminder that stingless does not mean defenseless.”
