What is it Wednesday: October 7, 2020

Can you identify what's in this photo?

 

 

Each Wednesday morning 

on Camp Lutherlyn's Facebook page

 the Lutherlyn Environmental Education Program posts a photo. 

 

 

Readers have all morning and afternoon 

to make their best guess about what the photo is. 

 

Around 6 pm LEEP provides the answer and a brief explanation.

 

 

Each week's What is it Wednesday post 

will also be posted on the Nature of Lutherlyn blog, 

 after it is posted on Facebook,

sometimes with additional bonus information. 

 

In addition to bringing you current editions of What is it Wednesday 

on the Nature of Lutherlyn blog, 

we will be reposting old editions,

creating a What is it Wednesday archive. 

 

This photo was posted as a What is it Wednesday on

October 7, 2020. 

 

 

 

And the answer is....

 

 

This is the nest of a leaf-cutter bee. 

Leaf-cutters are solitary bees, slightly smaller than honey bees, and similar in appearance but a bit darker.

Female leaf-cutter bees construct nests by cutting small circular pieces from the edges of leaves, which they stick together into a tube inside a hollow spot, usually in rotting wood or other narrow spaces. Each “cell” of the tube contains one egg, and pollen and nectar. Each nest may contain a dozen cells, and each female bee may create several nests, laying up to 40 eggs. When the egg hatches, the larva feeds on the pollen and nectar. The larva will eventually spin a cocoon and pupate inside the cell. The adult bee emerges from the cocoon and overwinters  inside the cell, then in the spring chews its way through the leaves and emerges to mate and begin the cycle again. (You can see the small holes left behind by the emerging adults in this old nest we found.) 

Leaf-cutter bees are good pollinators. Females collect pollen on many small hairs on the underside of their abdomens. This makes it easy for the pollen from one plant to brush off as a bee visits another plant, helpfully spreading pollen from plant to pant. There are native as well introduced species of leaf-cutter bees throughout North America. Leaf-cutter bees rarely sting, only when handled, and their sting is mild.

You can identify the presence of leaf-cutters near you by spotting the circular or half-circle holes left behind in the edges of leaves. Lots of other leaf-eating insects leave holes in the edges of leaves (caterpillars, beetles, katydids, walkingsticks, etc.). The holes left behind by leaf-cutter bees are very smooth and circular, while those left behind by other insects are more ragged and irregular. 

circular holes left behind by leaf-cutter bees, in redbud tree leaves

You may also find evidence of the leaf-cutter bees by finding their nests left behind in narrow gaps and holes in wood dead trees or man-made structures.  

Like and follow Camp Lutherlyn on Facebook, to see What is it Wednesday posts when they come out and have the opportunity to share your guesses in the comments!