July 2026 • Nebraskaland 31
Freeloader fl ie s
One day in late June, I arrived
to find a crab spider feeding on a
captured honey bee. As I bent closer,
t h o u g h , I n o t i ce d t h o se we re n't
the only two creatures involved in
the story. A handful of small dark-
colored f lies were hanging around
on the carcass of the bee. It wasn't
immediately clear what they were up
to, but some later research identified
them as freeloader flies, also known
as jackal flies.
Freeloader f lies often show up
to feed on prey caught and killed
by predators like spiders, praying
mantises and other invertebrate
predators. They are most often seen
on prey that release a strong chemical
odor when attacked. Honey bees are
a good example of that, often using
airborne pheromones to warn their
sisters of danger. Freeloader f lies
track down their food by following
just that kind of olfactory signal.
Freeloader flies feed on the carcass of a honey
bee captured by a crab spider.
