Robber Fly

Robber Fly with Kill

There’s a thief among us--
a predator who snatches one, then another, from her lookout on the rusty rail of the field fencing in my overgrown pasture.


She takes to the air and effortlessly grabs hapless insects in mid-flight, wrapping her spiny legs and clawed feet around some larger than herself, while some are smaller and easier prey.

Robber Fly with small wasp or ant

With little chance of escape, they’re instantly immobilized by a dose of neurotoxic and proteolytic enzymes deftly delivered through the tip her dagger-like proboscis.
Within minutes, she’s drinking them down.
Robbed of the life within, an empty shell falls to the ground.

Robber Fly preying upon Common Whitetail Dragonfly

Robber flies are skilled predators of the insect world and, though usually of no harm to humans, able to inflict a painful stab if handled carelessly. Many genera and species exist worldwide, some fairly small and some rivaling bumblebees and dragonflies in size.
This particular individual may be of the genus Promachus or Proctacanthus, both large and aggressive, bearded robbers.

There are many dragonflies left in my field.

Common Whitetail dragonflies
2 males (above) and female (below)