Robber Fly Smarts  (three photos)
Asilidae

From the first time I spotted one of these amazing insects, I have been fascinated by them.  Sunday, on the road to the Spiral Jetty* in
Box Elder County, Utah, I started bug-hunting along one of the Golden Spike tourist loops.  Before long I realized there were
 obviously a gazillion Robber Flies out there.  I pulled over to take some pictures of insects on Curly-cup Gumweed when a
Robber Fly lit on the ground not far from my car door. 

fly
I leaned out over the edge of the window, took a shot and exited slowly for a better angle.  It flew off. 
There's obviously
an unwritten law in the experienced Robber Fly world --"don't let anyone closer than eight feet".
  All of a sudden it
darted swiftly upward about four feet, nabbed a Beefly in mid-air and flew off to about ten feet from where I was standing.

robber fly and beefly
I shuffled in a little closer, took a shot, and then inched in a little more.  The Robber Fly tried to take off with its prey
but landed just a foot or so further west.  I could see it was having a little trouble flying with baggage.  I tried to
move in again and then it lifted off the ground like an overloaded hang glider, wobbled south about three feet
and jettisoned the fly into a bush.  Then it flew back to its  previous spot to wait me out.  I could see the Beefly
suspended in air between some branches, so I went to take a peek.  This is what I found.

net
It had dropped the Beefly into an old web for safekeeping.  I was a little stunned by its actions.  I guess most of us tend to
think of insects as little robots, but this shed new light on the thinking processes involved in survival.  Knowing it wasn't
going to be able to fly far with the Beefly and leaving it meant loss of lunch, it cleverly hid the Beefly where it could be
retrieved later (if I didn't steal the meal).   You may be thinking he probably dropped it by accident but to me the motion
looked too deliberate.  My hunch was correct.  It waited patiently until I got back in the car and retrieved the cache. 
Robber Flies are just amazing and so quick.  From what I've observed, they really like Beeflies;  must be a delicacy.
Anyone for a few sauteed insects?  © Carol Davis, 9-21-2008

*Just a note:  the road to the Spiral Jetty is dirt and, at the very end, needs much improvement.  In early summer, before the
sweltering heat sets in, you might occasionally spot birds (including owls), coyotes, badgers, lizards and other wildlife,
the wildest being large mosquitoes (they lapped up my insect repellent and whined for the bottle).
 I'm praying none of them were carrying West Nile...

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