Subject: A day of Freaky Flies
Location: Yarra Valley, Victoria, Australia
December 15, 2012 3:27 am
Hello Bugman, you’ve helped me before with a Bristle fly a couple of years ago. Today I’ve seen 3 strange flies on my cherry tree, which is currently being attacked by the cherry tree slug. I suspect they could be feeding on it, but I’m not sure.
It’s Summer here in Australia and today was a dull humid day.
Signature: Linda, Yarra Valley
Update: December 16, 2012
these are the best I could do. I hope they give you enough information to identify it. I noticed on the side-on shots a little white thing that looks like an egg on this fly. Is that normal anatomy or has it been parasitised? Just wanted to add, I didn’t harm any of the flies, they were all alive and well when I left them. The cherry tree slugs were another matter though.
Linda from Healesville
Thank you for sending the additional requested images. We originally thought this might be a Robber Fly and we maintain that opinion based on the beard visibly in the new photos. Alas, we have been unable to identify this Robber Fly to the species level. We believe the white object you refer to is a haltere, the vestigial wing structure of most flies. Flies are distinguished by a single set of wings, unlike most winged insects that have two pairs of wings.