Balloon-faced Flies, Part 2

A week ago, I wandered to the edge of my yard and noticed some agromyzid fly leaf mines in the bush honeysuckle (Diervilla lonicera) that I’m fairly sure are unknown to science.  So I stuffed a good number of leaves into some vials in an attempt to get some adult flies.  That evening I noticed a 1.5-mm braconid wasp in one of the vials:


The next day I was examining each of the leaves in that vial to look for the hole from which the wasp had emerged, and I noticed a funny little lump.  I looked at this under the microscope, and discovered that it was a fly in the process of emerging, its ptilinum fully expanded.  As quickly as I could, I adjusted the magnification on my camera lens and the exposure and angle of my flash heads, and I got the lens in focus just as the fly finished emerging from the leaf.


I took a few more shots in rapid succession, which show the balloon quickly receding.




Five minutes later, it was looking like a proper fly, except its wings were still expanding.


The next day, it had darkened considerably and its wings were fully functional.


Maybe someday I’ll manage to get a shot of a little fly balloon head just beginning to poke out of a leaf, but these shots are at least an improvement on my series from two years ago.

In a few months, I’ll send Owen Lonsdale all the agromyzids I’ve accumulated this year, and we’ll see what these bush honeysuckle flies turn out to be.

About Charley Eiseman

I am a freelance naturalist, endlessly fascinated by the interconnections of all the living and nonliving things around me. I am the lead author of Tracks & Sign of Insects and Other Invertebrates (Stackpole Books, 2010), and continue to collect photographs and information on this subject. These days I am especially drawn to galls, leaf mines, and other plant-insect interactions.
This entry was posted in Uncategorized and tagged , , , , , , , , , , , . Bookmark the permalink.

10 Responses to Balloon-faced Flies, Part 2

  1. Wendy Morelock says:

    That is just… wow.

  2. Annie Runyon says:

    Love these photos! Years ago I spent hours watching house flies emerge like this under a microscope, sketching them for an ink illustration for a publication … it was a challenge … and my kitchen filled with buzz while I worked.

  3. Jeffrey Eiseman says:

    Quite the progression! Good thing that your camera is always handy.


  4. What a really neat series. So glad you caught it.

  5. troymullens says:

    Outstanding series of photos.

  6. Pingback: Balloon-faced Flies, Part 3 | BugTracks

  7. Pingback: How Many New Species? | BugTracks

  8. Pingback: Another year, another 20 new species | BugTracks

  9. Pingback: How Many New Species? 2021 Update | BugTracks

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s