- Author: Kathy Keatley Garvey
A freeloader. A moocher. A sponger.
That's the freeloader fly.
A praying mantis is polishing off the remains of a honey bee. Suddenly a black dot with wings edges closer and closer and grabs a bit of the prey.
So tiny. So persistent. So relentless. That's the freeloader fly.
Don't look at the mangled honey bee. Don't look at the hungry praying mantis.
Look at the freeloader fly. Wait a few seconds and you'll see another.
The scene: a camouflaged praying mantis is tucked beneath some African blue basil leaves and the light is fading fast. (You could say I took this image "on the fly.")
Senior Insect Biosystematist Martin Hauser of the Plant Pest Diagnostic Branch, California Department of Food and Agriculture (CDFA) identified these "freeloader flies" as family Milichiidae and "likely the genus Desmometopa." See Wikipedia.
They are so tiny, Hauser says, that the mantids, spiders and Reduviidae (think assassin bugs) "don't bother chasing them away or even trying to eat them."
Hauser pointed out images of freeloader flies from BugGuide.net: http://bugguide.net/node/view/23319/bgimage
And look at all the freeloaders on this prey: http://bugguide.net/node/view/512989/bgimage
Back in March of 2012, agricultural entomologist Ted C. MacRae who writes a popular blog, Beetles in the Bush, posted an image of an assassin bug eating a stink bug. Check out all the flies engaging in what he calls kleptoparasitism--stealing food.
Everybody gets fed. Nobody leaves hungry.