Black & White Giant Fly
S1, Female, Face
Black & White Giant Fly
S1, Female, posterior
Black & White Giant Fly (Formosia speciosa)Class: Animals (Animalia) - Jointed Legs (Arthropoda) - Insects (Insecta)
Order: Flies (Diptera)
Family: Bristle Fly (Tachinidae)     iNaturalist Observation
Species: Black & White Giant Fly (Formosia speciosa)
This Photo:     S1, Female, anterior
Other name: Black and White Giant Fly

Thank you Reiner Richter & James Lumbers for confirming the id of this species for us

General Species Information:
Found on Ellura (in the Murray Mallee, SA) and elsewhere
~17mm long. This is large fly, similar in size to Rutilia flies. While we're used to Robber flies being longer, they are thin. But this beast is rotund like a blow fly. Thankfully, it wasn't agressive.
It's hard to say if it's pure size is what it stand out so much, or the sharp contrast of the balck & white patterns on it's body. But stood out it did!
It's always been intrigueing to see the 3 jewels on the top of wasp heads. This is the first time we've seen them on a fly. On searching, they also appear on Hover flies. It seems that they are smaller, and so not visible on small or hairy flies.

AHHHH, finally found out. The "3 jewels" as we call them are actually simple eyes, each with a single lens! They are called "Ocelli". Not much is known about them, but they seem to help with detection of the horizon in flight.

Copyright © 2014-2024 Brett & Marie Smith. All Rights Reserved. Photographed 14-Dec-2014
This species is an Australian Native Species, not listed in the SA Murray Mallee Survey of 2010.