LOOK!  UP IN THE SKY!
It’s a bird! It’s a plane!
No, it’s…AMBUSH BUG?!?

Who or what is “ambush bug?”

The label applies to two totally different entities. One is stumbling, bumbling, thoroughly silly comic book character who sorts of buzzes around like Superman. The other is a highly efficient, anything-but-silly garden predator that probably buzzes around the flowers in your garden.

Ambush Bugs, Phymata sp., are true bugs that belong to the same family as wheel bugs and assassin bugs: Reduviidae. It is shorter and stouter than its assassin bug cousins, being only about ½ inch long. Most are brightly colored, in shades of yellow, orange, red and greenish-yellow.

The Jagged Ambush Bug (most likely Phymata fasciata or P. americana, but not yet confirmed) is fiddle-shaped, with an abdomen that flares beyond the closed front wings. Its front legs are thick and shaped like those of a praying mantis, a perfect design for grabbling and holding prey.

All these physical traits enable Jagged Ambush Bugs to fit perfectly into their ecological niche. A poor flyer, each slow-moving bug hides on flowerheads (goldenrod is a favorite) and waits motionless for its prey to come to it.

It grabs an unsuspecting arthropod, stabs it with its beaked proboscis and injects poison. The poison not only paralyzes the victim, it also liquefies the body’s contents, and turns it into a kind of arthropod soup. The Jagged Ambush Bug then slurps up the bodily fluids with its rostrum, a straw-shaped organ in the proboscis.

Like other hemiterae (true bugs), the life cycle of the Jagged Ambush Bug involves simple metamorphosis. Black, barrel-shaped eggs are laid on stems and leaves during warm months and then covered in a protective layer of frothy "cement."

Young nymphs look like miniature adults without wings. Nymphs will go through at least 4 molts as they increase in size. Nymphs are just as competent at predation as adults. Eggs and adults can overwinter to the next spring; however, there is usually only one generation a year.

Because of its small size, colorful camouflage, potent poison and surprise tactics, the Jagged Ambush Bug is able to catch and eat insects that are much larger than it is, such as bumblebees, hornets and wasps. This list also includes honeybees, which does not make Jagged Ambush Bugs popular with beekeepers.

As always, whether an insect is seen as beneficial or harmful depends on an individual gardener’s goals. The Jagged Ambush Bug’s menu can also include thrips, flies, moths, butterflies and other true bugs, which may serve to make it more welcomed in many gardens.

FIGURE 1. The Jagged Ambush Bug is fiddle-shaped, with an
abdomen that flares beyond the closed front wings.

FIGURE 2. Because of its small size, colorful camouflage,
potent poison, and surprise tactics, the Jagged Ambush
Bug is able to catch and eat insects that are much larger
than it is.