Thieving Parasites?

 

Alas, poor bee. One must take care when buzzing about flowers, for danger lurks around every petal. I had seen this tableau before, with other bees on other flowers, a motionless individual dangling. 

The culprit, I assumed, was a Jagged Ambush Bug, those fearsome predators that sit motionless in wait for a hapless pollinator to wander within snatching distance of its strong forelegs. Once within the Ambush Bug's clutches, the victim is subjected to "extraoral digestion": saliva from the Ambush Bug is injected via its proboscis, breaking down the victim's tissues so they can be easily sucked out.

I  pivoted to get a shot from another angle...

...and yep! Not one but two Jagged Ambush Bugs, a smaller male piggybacking on the larger female, who was feeding on the bee. 

But wait--what's this? Tiny flies hanging around the scene, several on the bee itself. Are they sharing in the Ambush Bug's meal, crashing the party to partake of the nutrients available on the bee's corpse?

iNaturalist tentatively suggests an ID in the family Milichiidae, known as "freeloader flies" for their kleptoparasitic ways (kleptoparasites take food from others, with "klepto" meaning "thief" or "theft"). I am not knowledgeable enough to confirm the ID, but the behavior certainly fits!

"Freeloader flies" (also called "jackal flies") will feed off the prey of Ambush Bugs, spiders, and other predators, possibly even sucking the juices the predator has conveniently dissolved for them as part of its own meal. They are attracted by the smell of the prey insect. 

When I imagine how nice it would be to pollinate for a living, buzzing happily from flower to flower in the sunshiny summer, I must remind myself that it's a dangerous, yet complex and fascinating, world.