Assassin Bugs

Assassin bug makes a meal out of a Japanese beetle in my garden. (Photo by Charlotte Ekker Wiggins)

Assassin Bugs

Looks like we do have a garden ally in our quest to control Japanese beetles, the assassin bug!

I have seen a few of these in my garden in the last couple of years. They are quick and retreated when I tried to approach so I just kept an eye out for them. Since I don’t use pesticides in my garden, I have been seeing more of them and they are most welcome, especially when I caught the large light grey one making a meal out of a Japanese beetle.

Assassin bugs (family Reduviidae) are predatory insects that are of great benefit to gardeners so they fall under the beneficial insects category along with praying mantis and ladybugs. They capture and feed on a wide variety of prey including Japanese beetles, flies, caterpillars and yes, sometimes bees.

The assassin bug sits quietly until the prey gets close enough for them to stab it with its long mouthparts. After being immobilized by a paralyzing toxin, the prey’s body fluids are then drawn through the assassin bug’s soda straw-like mouthparts, very much like a bug drinking a milk shake.

Several insect books noted most species of assassin bugs are gray to black or brownish in color, though some unique to ecosystems can also be bright.

There are several kinds of assassin bugs:

Ambush bugs are a type of assassin bug that lie in wait for their prey on flowers. Some of these species are colored to blend in perfectly with their flower hiding places.

The wheel bug is the largest of the 150 or so species of North America assassin bugs. Adult wheel bugs are gray and approximately 3 cm (1 ¼ inches) long. Its name comes from the distinctive, cog-like crest arising from the top of the thorax, or middle section, of the wheel bug’s body . Wheel bugs will attack larger insects like grasshoppers and larger caterpillars.

Although most assassin bugs are highly beneficial, the cone nosed bug or kissing bug is parasitic on humans and other mammals. Cone nosed bugs have the same elongated head as the wheel bug, but can be distinguished from wheel bugs by their lack of a crest and by their orange and black markings where the abdomen extends laterally past the folding wings.

This assassin bug patrols one of my dwarf cherry trees. (Photo by Charlotte Ekker Wiggins)

Don’t Mess With Assassin Bugs

The bug’s name is enough to keep me at bay but I know some people like to fiddle with what they find in their gardens. Some assassin bugs, most notably the wheel bug, will bite if picked up and handled carelessly. The bite of the wheel bug is immediately and intensely painful.

See bug name as motivation not to pick it up!

Persons who are bitten should wash and apply antiseptic to the site of the bite. Oral analgesics, such as aspirin or ibuprofen, may be useful to reduce the pain. Treatment by a physician is not usually needed.

As with any insect sting or bite, the victim should seek medical attention immediately if there is any sign of anaphylactic reaction, such as generalized swelling, itching, hives or difficulty breathing.

Charlotte