21 February 2006 - 19:46Bee A Wasp: An Amber Identity Crisis

“A huge lizard!”

One of the diggers had just brought a new specimen from the mine and he was glowing. You don’t see a dirt-weary ambero glowing like that every day unless he’s in love, drunk or truly found something special.

The piece did look interesting, yet strangely warped for a lizard. Too transparent. No distinguishable legs. No skeleton. So the piece got polished.

No, this wasn’t a lizard. We didn’t know what it was, except for a few odd hexagonal cells that were way to exact to be there just by chance. What objects in nature have hexagonal cells?

The most obvious assumption is of course that they are honeycombs. However, there are a few problems with this conjecture. The Western Honeybee (apis mellifera) — the bee as we know it — is not native to the American continent. It was first introduced to South America approximately 500 years ago. The hexagonal enclosures in piece of amber from La Toca mine however date back 35 - 40 million years (J.A. Santiago-Blay and G.O.Poinar jr). What gives?

ROYAL LADY

The honeybee may still have buzzed about Europe and Africa when the Amber was still resin, but another species of bee did exist and it is the Mayan culture that reminds us of this.

The Mayans were the first to actually keep bees as pets and harvest the honey, calling them Xunan Kab, the Royal Lady. The bee species they kept is now identified as a type of stingless honeybee (Melipona beecheii but also Melipona yucatanica) that differs from the traditional Western Honeybee in the fact that is does not, well, sting.

It does however bite and it doesn’t build hives the way western bees do. Instead Xunan Kab builds pots irregularly arranged around a central brood comb where the larval bees are housed. The pots may be circular, but it is the brood comb that is hexagonal.

Since Hispaniola and the South American continent used to be connected, could our specimen indeed be a brood comb of a great-great-great-grandfather of the Xunan Kab?

Maybe, if it weren’t for the other insect that builds hexagonal nests and resides within the Apis family.

WASP

Wasp nests look shockingly similar to our hexagonal cells, plus they have the advantage of having been previously identified in Miocene Amber as a new species of the paper wasp genus Agelaia Lepeletier (Hymenoptera: Vespidae; Polistinae, Epiponini). At least three other finds of similar kinds have been studied and identified.

Some Agelaia species also have the habit of building their nests in fallen tree trunks near ground level, which would be a perfect location for resin to accumulate.

Unlike bees, wasps build their nests of paper, not wax. Unfortunately it is hard to identify the former consistency of a material after it has become a rock. Opinions seem to split in this regard. Some feel that our specimen appears to be more paper than wax, while others are of the opinion that it is more wax than paper.

Whipping out Occam’s Razor, one could postulate that the find is indeed wasp, not bee. But Occam’s Razor is a double-bladed sword, and at this point a comparative study on those cells, including measurements, shape of the cells and their composition is needed.

And to fuddle up the issue a bit more, here come Larry, Curly and Moe.

THE THREE STOOGES

Not far from the main hexagonal complex we find three unidentified larvae. The first logical assumption would be to state that they may be bee pupae, swept out of their brood comb by the gushing resin. Experts we have consulted (among them the world’s leading Amber expert George Poinar) disagree among each other in matters of the origin of the hexagonal shapes, but they all seem to be in accordance in the point that the larvae are not pupae of any kind, but most likely scavenger, inquilines, or even some parasitoid type of larvae (a wax moth larvae?).

The thing is, most insect larvae pretty much look the same. Some may have anterior true legs or pseudolegs, which could indicate wax moth larvae for instance. But here is another problem we face: Larry and Curly both look to be legless, while Moe seems to have some type of legs.

In any case, they seem not to help in identifying the hexagonal cells, since scavenger larvae are popular in all types of nests, be they honeybee, stingless bee or wasp.

The nature of this specimen is still heavily debated and requires further study. Without any doubt, it is a rare fossil of hexagonal cells and could be an interesting scientific study object, especially for a museum or any other specialized institution.

(The piece is currently part of the private
Amber Ranch Collection)

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Some further reading:

Camargo, J. M. F., J. S. Moure & D. W. Roubik, 1988. Melipona yucatanica , New Species (Hymenoptera, Apidae, Meliponinae): Stingless Bee Dispersal Across the Caribbean Arc and Post- Eocene Vicariance. Pan-Pac. Ent., 64(2): 147-157.

Carpenter, J.M., and Grimaldi, D.A., 1997. Social Wasps in Amber. Am. Mus. Novitates 3203 : 7pp., 4 figs.