All "bugs" aren't bad. Entomologists call insects that belong to the suborder Heteroptera (order Hemiptera) the "true bugs" and 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 meat-eaters. The common name for the family clearly describes how these predatory stealthy hunters make a living.
Family members sport two features important to their predatory behavior: raptorial front legs and piercing-sucking mouthparts. The front legs of the assassin bug are designed for grabbing and holding prey. Their mouthparts called a “beak,” then swing into action (literally) to inject paralyzing and pre-digestive enzymes into their prey. They then suck the essence-of-insect from their hapless victims.
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.
Assassin bugs develop from eggs to adults through "incomplete" metamorphosis. I've never liked this term because it sounds like something goes horribly wrong during development like only having legs on one side of their bodies so they run around in circles (just kidding). It actually means that they only pass through three developmental stages: eggs, nymphs, and adults. In contrast with "complete" metamorphosis, there is no pupal stage.
The nymphs of many insects with incomplete metamorphosis like grasshoppers (order Orthoptera) look like a miniature version of the adults. However, assassin bug nymphs look nothing like the adults.
In fact, many types of assassin bug nymphs are commonly mistaken for spiders. A good example is the nymphs of our native wheel bug (Arilus cristatus). Of course, spiders have eight legs while wheel bug nymphs have six legs.
Wheel bug nymphs are one of the most common types of assassin bug nymphs currently patrolling trees and shrubs in Ohio. The nymphs hold their curved abdomens upright as they parade around on their long, spindly, spider-like legs … unless three on one side fail to develop and they run around in circles which is why they're called wheel bugs (just kidding!).
The adults are called wheel bugs because of a peculiar feature that rises from the top of the 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. They will appear on the tree scene later this season in Ohio.
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 uniformed 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" sounds non-threatening until you learn that several species of bugs belonging to the genus Triatoma tend to bite near a person's mouth like they're kissing a person (eww!). 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 (double eww!). 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.
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.