A primitive bee from 100 million years ago has two things in common with bees of today; pollen and a parasite that caused its demise, much like varroa mites cause periodic colony collapse disorder today.
The mid-Cretaceous fossil from Myanmar provides the first record of a primitive bee with pollen and also the first record of the beetle parasites, which continue to show up on modern bees today. Beetle parasites may have caused the flight error that was deadly for the insect. The Discoscapa apicula specimen became stuck in tree resin and thus preserved in amber, and has now been identified as a new family, genus and species. The new find has been classified as Discoscapa apicula, in the family Discoscapidae.
Insect pollinators aid the reproduction of flowering plants around the globe and are also ecologically critical as promoters of biodiversity. Bees are the standard bearer because they're usually present in the greatest numbers and because they're the only pollinator group that feeds exclusively on nectar and pollen throughout their life cycle.
Bees evolved from apoid wasps, which are carnivores. Not much is known, however, about the changes wasps underwent as they made that dietary transition.
The fossilized Discoscapa apicula bee shares traits with modern bees - including plumose hairs, a rounded pronotal lobe, and a pair of spurs on the hind tibia - and also those of apoid wasps, such as very low-placed antennal sockets and certain wing-vein features.
"Something unique about the new family that's not found on any extant or extinct lineage of apoid wasps or bees is a bifurcated scape," said Oregon State University researcher George Poinar Jr., referring to a two-segment antennae base. "The fossil record of bees is pretty vast, but most are from the last 65 million years and look a lot like modern bees. Fossils like the one in this study can tell us about the changes certain wasp lineages underwent as they became palynivores - pollen eaters."
Numerous pollen grains on Discoscapa apicula show the bee had recently been to one or more flowers.
"Additional evidence that the fossil bee had visited flowers are the 21 beetle triungulins - larvae - in the same piece of amber that were hitching a ride back to the bee's nest to dine on bee larvae and their provisions, food left by the female," Poinar said. "It is certainly possible that the large number of triungulins caused the bee to accidently fly into the resin."