Last week I posted a photo of a very odd leaf structure that a co-worker at the National Wildlife Federation found in her yard in the Washington DC area. The cigar-shaped structure was created by an animal, and is something that most people don't regularly get to see. So I posted here to Animal Oddites to see if anyone could guess the identity of the animal that made it.
After a several days, only one person correctly guessed what made the leafy tube on my Facebook page.
The answer is, of course, a leaf cutter bee (Megachile spp.).
There are many species of leaf cutter bee, and like most of the over 4,000 bee species native to North America, they are solitary and don't form hives like the introduced honey bee. Instead, they lay their eggs in tunnels they've excavated in dead and decaying wood or inside the stems of pithy plants.
Lacking a hive of sisters to care for and protect their young, each female leaf cutter bee instead creates a protective tube made out of circular bits of leaf which they cut with their mandibles. They use the leaf-rounds to construct a multi-chambered tube, in which they lay a series eggs. They provision each egg with a ball of nectar and pollen known as a "bee loaf." Each newly hatched larva will feed upon the bee loaf, growing and eventually pupating. When metamorphosis is complete, it will emerge from the leaf tube to head out into the world to begin the process anew.
Nature really is amazing, isn't it?
Here are some great pics of leaf cutter bees in action.
Female Leaf Cutter Bee Cutting a Leaf
After the Cut
Female Leaf Cutter Bee Entering Nesting Tunnel
Leaf Cutter Bee Nesting Tube
Find out how to attract native bees from the National Wildlife Federation.