Are all insects considered beetles?
Entomologists – experts in the field of zoology who study insects – have identified 800,000 different species of insects.
Entomologists reserve the bug name for a specific group of insects belonging to the suborder Heteroptera (order Hemiptera). To emphasize the point, entomologists refer to these heteropteran insects as the true bugs, which may mean that we consider all other insects to be false bugs, but this is not true.
Entomologists refer to real bugs based on their mouthparts. Real bugs suckle: They have special mouthparts that are used to suck up juices. Mostly they suck fluids from plants, but there are some real bugs, like bed bugs, that feed on animals.
The sucking mouth part, called the proboscis (pro-boss kiss), differs from that of other insects. With a high-powered microscope, it is easy to see that real beetles have mouths that look and function differently from other insects. It looks like a long beak and works much like a straw you could use to drink from a juice box.
If you look at the mouthparts of other insects with a beak-like proboscis, such as a honey bee or a butterfly, you can see by rolling up that the proboscis can be retracted. A real beetle’s trunk is not retractable. Insects with moveable mouthparts, such as beetles and grasshoppers, allow them to move food from source to mouth. A real beetle’s trunk is stiffer and cannot be rolled up.
The real beetle that is now appearing in the landscape belongs to the family of heteropteran Reduviidae. Known collectively 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, clandestine hunters make a living.
Family members have palpable forelegs designed for grasping and holding prey. Its stinging and sucking trunk looks like a beak. It literally swings into action to inject crippling and predigestible enzymes into prey, which is mostly another insect. Then they suck the essence of the insect from their unfortunate victims.
Killer bugs develop from eggs to adults through incomplete metamorphosis. This means that they go through three stages of development: eggs, nymphs, and adults. This is in contrast to insects like butterflies, which develop from eggs to adults through complete metamorphosis, where complete change occurs during the pupal stage.
The nymphs of many insects with incomplete metamorphosis, such as grasshoppers (Ordhoptera), look like a miniature version of the adults. However, killer bug nymphs do not generally look like adults. In fact, many species of killer bug nymph are often mistaken for spiders. A good example are the nymphs of our domestic 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 species of killer bug nymphs currently patrolling trees and shrubs in Ohio. The nymphs keep their curved abdomen erect as they walk around on their long, spindly, spider-like legs.
The adults are called wheel bugs because they have a special characteristic that rises from the top of the beetle’s rib cage. The structure looks like half a gear, with the teeth clearly visible. Wheel bugs are large, measuring over 1 1/4 inches long, and their color varies from light gray to bluish-gray to gray-brown. They’ll make an appearance on the tree scene in Ohio later this season.
Caterpillars in the order Lepidoptera and sawfly larvae in the order Hymenoptera are preferred by these voracious predators; However, with other arthropod tidbits, they won’t turn up their beaks.
Although these are beneficial insects, they should not be handled; they can cause a painful bite to people. The pain from an insect bite has been described as equal to or more severe than a hornet sting, and wound healing can take over a week.
Wheel bugs were the focus of an insect hysteria that swept through Ohio and other states in 2015. The panic was triggered by a number of unfortunate events, beginning with wheel bugs being mistakenly identified as kiss bugs. The name “kissing bug” doesn’t sound ominous until you learn that several species of beetles in the genus Triatoma tend to bite near a person’s mouth as if they were kissing a person. These “triatomic bugs” get away with their cheeky behavior by biting people while they sleep.
The bites are usually painless, but if the beetles harbor the single-cell Trypanosoma cruzi in their intestines, they can lead to serious illness. The beetles do not inject the protozoa when they bite; they release it on their other end when they defecate. Infection occurs when the protozoon is accidentally rubbed into the beetle’s food wounds or onto mucous membranes such as nasal passages. The resulting Chagas disease can be fatal.
Fortunately, the kissing bug Chagas disease association occurs only in Central and South America with some rare occurrences in Texas.
Although wheel bugs and kiss bugs belong to the same family, their lifestyles are completely different. Wheel bugs suck insect sap; Kissing bugs suckle animal blood.
However, with their long, spindly legs, large bodies, narrow, pearl-eyed heads, wheel bugs share family traits with their kissing cousins. As a result, images of wheel bugs identified as kissing bugs appeared on the Internet.
There is a kiss beetle called Bloodsucking Conenose (Triatoma sanguisuga) that can be found in the northern United States, including Ohio. Although it has a scary-sounding common name, conenosis is very rare in Ohio, and it does not acquire or spread the protozoa that are responsible for Chagas disease. So we can sleep peacefully.
