Wheel bugs (Arilus cristatus) have reached the adult stage in Ohio and the big bugs are lumbering about on trees and shrubs in search of prey. The "wheel" in 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 over 1 1/4" long, and their color varies from light gray to bluish-gray to grayish-brown.
Wheel bugs and kissing bugs (Triatoma spp.) belong to the same taxonomic family, Reduviidae; the so-called "assassin bug" family. They both share several family features including large bodies, long spindly legs, a narrow head, beady eyes, and a long "beak" at the front of their head. Even though the bugs belong to the same family, their lifestyles are completely different. Wheel bugs suck insect juice; kissing bugs suck animal blood.
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.
Their similar appearances made it difficult to put the bugs back in the bottle once the panic became amplified by misinformed social media postings (surprise?). Indeed, wheel bugs and a few other true bugs continue to be misidentified on social media as kissing bugs.
Two of the most common faux-kissers appearing on social media are boxelder bugs (Boisea trivittata) and western conifer seed bugs (Leptoglossus occidentalis). Both of these bugs feed primarily on plant seeds but cause little real damage.
However, these bugs have a habit of invading homes in the fall; sometimes in large numbers, to find a warm, cozy place to spend the winter. They can be serious nuisance pests and scare the bejeebers out of homeowners if misidentified as hungry hordes of kissing bugs riding the apocalyptic pale horse of pestilence.
What's in a Name?
The "bug" in wheel bug, kissing bug, boxelder bug, and conifer seed bug means these insects belong to the taxonomic suborder Heteroptera within the order Hemiptera. Heteropterans are collectively known as the "true bugs." It's why "bug" is written separately in the names.
"Hetero-" is Greek for "different." The suffix, "-ptera" means "wing." It's why pterodactyl starts with a "p;" the name translates to "winged finger" (-dactyl = finger, or toe). Combine hetero- with -ptera and you get Heteroptera which means "different wing." If you look closely at a wheel bug or most other heteropteran species, you'll see that the front wings have both membranous and hardened areas. I could go on and on about the name game, but you get the picture.
Wheel of Misfortune
Wheel bugs are highly effective hunters able to sneak up and grab some of the most powerful and well-armed insects in Ohio. The bugs 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.
Once wheel bugs 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 bugs suck the essence-of-insect from their hapless victim.
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. I once watched a wheel bug grab and dispatch a bald-faced hornet which is no easy meal.
Indeed, they will even nail the probing fingers of careless entomologists and uniformed gardeners! While these are beneficial insects, they should not be handled. The pain of a wheel 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.
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.
People living in Ohio shouldn't lose sleep over contracting Chagas disease unless they travel to more southern climes. Conditions don't support the same kissing bug / Chagas disease relationship here in Ohio. The highest concentration of the disease occurs in Mexico as well as Central and South America.
However, kissing bug madness reemerged in 2018 when a bug was reported to have bitten a young girl in Delaware (the state, not the city in Ohio). The bug was identified by the Delaware Department of Agriculture and confirmed by the Centers for Disease Control and Prevention as being Triatoma sanguisuga which is, in fact, a type of kissing bug. That’s when the bug pooh hit the media fan.
The names attached to this kissing bug sound threatening. The specific epithet, "sanguisuga," means "bloodsucker." It's approved common name is "bloodsucking conenose." It sucks blood using piercing-sucking mouthparts attached to a cone-shaped nose-like structure at the front of its head.
Adding to the panic, a number of the news stories implied the bug recently arrived from South or Central America. This is not true: it's already here. All of my pictures shown here of the bloodsucking conenose were taken of specimens collected in Hamilton or Butler counties. However, the bugs did not recently arrive recently from points south; the bloodsucking conenose considered a native insect.
According to a paper published in the Ohio Journal of Science in 1960 titled, "Arthropods of Medical Importance in Ohio," the bloodsucking conenose is found in southern Ohio. The bug is very rare. It feeds like a giant mosquito on the blood of small mammals living in forested areas. These animals are not known to serve as a reservoir of the Chagas protozoan. The disease cycle is further hampered by the extreme rarity of infectious people living in Ohio. Certainly, a Chagas disease sufferer may travel back to Ohio from a place where the disease is endemic, but what are the chances of an untreated person meeting with a bloodsucking conenose?
Equally important, studies have shown that even if the bloodsucking conenose feeds on a human victim carrying the Chagas protozoan, the bug is a very poor vector. The primary reason is its feeding behavior; it seldom defecates on its victims. Remember that the bugs don't inject the protozoan when they bite. Infection only occurs if the protozoan in the bugs pooh is accidentally rubbed into the feeding wounds or onto mucous membranes such as nasal passages.
There are several kissing bugs found in Mexico and South and Central America that are much better pooh spreaders, thus they are better vectors of the Chagas protozoan. One of the primary vectors in that part of the world is T. infestans which goes by the common name, vinchuca. However, you can sleep tight at night; this bug is not found in our part of the world.