Earth Notes: Sandstone Bees

Oct 25, 2017

The Colorado Plateau’s harsh environment is a fitting home for a wild bee so tough it chews nest holes into solid rock. These rare sandstone-nesting bees, recently named Anthophora pueblo, are active for only a short time each spring, avoiding blazing summer heat.

Sandstone-nesting bee
Credit Michael Orr

Bee researcher Frank Parker discovered the bees nesting in cliffs in Utah 40 years ago. He took a chunk of sandstone containing nest holes to his lab and watched it for years. He learned that the wormlike bee larvae within can sleep for up to four years before emerging as adult bees.

In 2015, doctoral student Michael Orr found intriguing nest holes in a rock face in the desert. Orr and Parker examined the old samples and new nests and found many more nest sites in sandstone across the Plateau.

The bees excavate nests near creeks, probably sipping water and using it to soften the sandstone as they chew through with their strong mandibles. Female bees provision their chambers with a supply of pollen and nectar, lay an egg in the chamber, then seal it with sand.

When a bee larva hatches, it devours the pollen and nectar. Then the larva sleeps safely in the climate-controlled rock environment until the weather is perfect for the flowers it visits. Finally, an adult bee emerges from the nest hole to find a mate and begin the cycle again.