I was hiking with my daughters, and noticed perfectly drilled holes in the trail itself. At first I thought it might be due to the poles so many hikers use for stability as they climb, but as I looked closer I realized these were tunnels. And upon the entrance of some of these tunnels were traces of pollen! This, of course, made me pause and wait for a few minutes, in hopes of crossing paths with my favorite pollinators, native bees.
The three of us patiently waited, and before long in came a bee, a very fast bee who dove into the tunnel bearing loads of pollen all over her legs. I was ecstatic, and began clicking away with my camera. The unfortunate part was I was without my trusty macro lens, which would’ve been so much better at capturing the tiniest of details. This just means I need to go back soon!
These two bees were fighting over the tunnel. Maybe they were confused about whose tunnel was whose? The one on the top was finally shoved off by the one in the tunnel; bee battle at its best. You can see the leg warmer hairs on her legs in the photo below. These hairs are called scopa, which are thick hairs that curve back toward the surface from which they grow. This works well for carrying pollen without having to mix it with nectar and pack it in as honeybees do.
I suspect these bees are of the Diadasia genus, as many of the tunnels we saw had walls around the entrance of the nesting tunnels. Additionally, they were nesting in the compact soil of the trail itself, which is also characteristic of Diadasia bees. Finally, they had thick hairs on their hind legs. Diadasia love cactus and mallow blooms, making them key players in the reproduction of these plants.
As we were observing this area, we came across two more species of bees. One was nesting in the side of a hill, and she had a much different appearance from the bees nesting on the trail. She lacked the thick scopa on her hind legs, which makes me think she had a belly full of scopa, but she was too quick for me to get a closer look. She also had really pretty green compound eyes, whereas the others had black compound eyes. This bee looks to be Anthidium, a wool carder bee, who uses the hairs of plants to line their nests, and to partition between developing bees. She is known for taking over abandoned tunnels, or sometimes even digging her own, but this is the exception to the rule.
As if these two discoveries weren’t enough, we found one more buzzy bee nesting in a tunnel on the trail. Her coloring was much different from the other two with black and yellow stripes and black eyes. She appeared to be playing Peek-A-Boo with us as she peered out and dropped back into her tunnel upon seeing our persistent presence. This is a bee I was very excited to see, as I suspected it might be Paranthidium, and upon a closer look, I can confidently say it was!
Paranthidium typically uses vacated nesting tunnels and partitions between rooms of developing bees using two plant resin walls with pebbles in between. However, I have a hard time believing she did none of this excavating, as the pile of soil around the opening appears to be fresh. Paranthidium bees like sunflower family plants, which is where all the resin comes from, and there were many in bloom where we went hiking.
What a fantastic day this was! I had a big smile on my face, as my girls jumped with delight at all the activity in one small area. All of these sightings because we took a few minutes to wait and watch the ground beneath us.
The next time you see perfectly drilled holes, take pause and see who resides there, chances are it’s a bee of sorts! Now waggle with us, and share this story with your friends!