Insects belonging to the Hemipteran family Reduviidae are collectively known as “Assassin Bugs.” The family includes over 190 species in North America and they are all are meat eaters. The common name for the family clearly describes how these stealthy hunters make a living.
Family members sport potent predatory equipment including strong raptorial front legs for seizing and holding prey and powerful piercing-sucking mouthparts to suck the life out of their victims. Assassins are highly effective stealthy hunters able to sneak up on some of the most powerful and well-armed insects. I once watched an assassin bug grab and dispatch a bald-faced hornet which is no easy meal.
Some assassin bugs like those in the genus Zelus have additional assistance with their grabbing power in the form of a sticky goo covering their front legs. The gluey material is produced by glands on their front legs making them function like sticky fly paper. You may find the Pale Green Assassin Bug (Z. luridus) hanging out on flowers waiting to grab a quick meal with their sticky legs.
Once the assassins seize their prey, they use their piercing-sucking mouthparts, called a "beak," to inject paralyzing and pre-digestive enzymes. In their final insecticidal act, the assassins suck out the essence-of-insect from their hapless victim.
Assassin bugs pass through three developmental stages: eggs, nymphs, and adults. This is known as "incomplete metamorphosis." However, unlike other incomplete metamorphic insects such as grasshoppers with the nymphs resembling miniature adults, the nymphs of some assassin bugs may look nothing like the adults.
In fact, the nymphs of our native Wheel Bug (Arilus cristatus) are often mistaken for spiders. The nymphs have long, spindly spider-like legs and they parade around with their abdomens held upright. Of course, insects have six legs and spiders have eight legs.
Wheel bugs are one of the largest and most common assassin bugs found in Ohio. Their name refers to a peculiar morphological feature that rises from the top of the adult bug's thorax. The structure looks like half of a cogwheel, with the gear teeth clearly visible. Wheel bugs are big, measuring almost 1 1/2" long, and their color varies from light gray to bluish-gray to grayish-brown.
Caterpillars and sawfly larvae are favored table fare of these voracious predators; however, they will not turn their beaks up at other arthropod meat morsels. Indeed, they will even nail the probing fingers of uninformed gardeners!
While these are beneficial insects, they should not be handled. All members of the family are capable of delivering a painful bite to people. The pain of a bug bite has been described as being equal to or more powerful than a hornet sting, and the wound may take over a week to heal. It is best to appreciate these beneficial insects from afar.
A Bug-Induced Panic
Wheel bugs were at the center of a bug hysteria that swept through Ohio as well as several other states in 2015. The panic was induced through a series of unfortunate events starting with wheel bugs being misidentified as kissing bugs (Triatoma spp., family Reduviidae).
The name "kissing bug" may sound non-threatening until you learn why they were given that name. Several species of bugs belonging to the genus Triatoma are collectively known as "kissing bugs" because they tend to bite near a person's mouth. These "triatomine bugs" get away with their cheeky behavior by biting people while they sleep.
The bites are usually painless but may lead to a serious disease if the bugs are harboring the protozoan Trypanosoma cruzi in their gut. The bugs don't inject the protozoan when they bite; they release it from their other end when they defecate. Infection occurs if the protozoan is accidentally rubbed into the bug's feeding wounds or onto mucous membranes such as nasal passages. The resulting Chagas disease is nothing to sneeze at; it can be deadly.
Thankfully, the kissing bug / Chagas disease connection only occurs in Central and South America with some rare occurrences in Texas. Conditions don't support the same relationship here in Ohio.
Even though wheel bugs and kissing bugs belong to the same family, their lifestyles are completely different. Wheel bugs suck insect juice; kissing bugs suck animal blood.
However, with their long spindly legs, large bodies, narrow heads with beady eyes, wheel bugs do share family features with their kissing cousins. Consequently, pictures of wheel bugs started showing up on the Web identified as kissing bugs. That spawned an alarm that rippled through several media outlets.
The second round of bug-induced panic occurred back in April. This time, it was based on the reality that there is a kissing bug called the Bloodsucking Conenose (Triatoma sanguisuga) that may be found in the northern U.S. including Ohio. Although it has a scary sounding common name, the conenose is very rare in Ohio and it doesn't acquire and spread the protozoan responsible for Chagas disease. You can read about this second panic in a BYGL Alert that I posted on April 25 titled, "Kissing Bug Hysteria Rises Again," by clicking on this hotlink: https://bygl.osu.edu/index.php/node/1243