What?

Recently I was trying to photograph some very small bees.  When I'm doing this, I'm often following the blur of a bee in flight.  I can't see any detail; I just try to follow the bee until it lands and then focus the lens.

This time I was surprised.  First, because this one turned out to be a fly, not a bee.  And second, because the fly started to oviposit (lay eggs) in a Yarrow (Achillea millefolium) leaf!  What?

 

In the photo above, the fly has curled her abdomen tip down into the leaf.  This is a classic egg-laying position for many insects.

Here's what she looked like with her abdomen extended:

 

I don't think I've noticed a fly ovipositing in a leaf before, but then again, I don't think I've ever tried to find one doing it, either.