From external appearances alone the Wheel Bug looks downright silly, but if ever there were a critter that deserved the name of “Devil’s Riding Horse” it is this insect. It is not an especially vicious beast, nor is it dangerous in the true sense of the word, but it does pack some nastiness behind those goofy looks. Don’t let those “put together by a committee looks” fool you. This fellow deserves respect.
The Wheel Bug comes from a family of true bugs called Assassin Bugs, so that alone should key you into its reputation. It is, in fact, the largest local member of this clan and so, by default, can be considered as the head assassin of the family (the Don, you could say). Assassin bugs kill their prey – usually other soft-bodied insects – by plunging their stiletto shaped beaks into their victims and sucking out the innards. The formidable assassin’s beak of the Wheel Bug is nothing short of a fang. There is even a groove on the underside of the thorax which is used for safely storing the tip of this weapon (see below). When this predatory tool is driven home, the bug then uses it to inject a toxic and paralytic substance that both immobilizes the subject and renders its internal organs into mush. In short, the victim is turned into a box drink as the juicy juice is sucked up by the killer. True to the assassin’s code, there is no emotion in the kill– it’s just a job in order to stay alive.
They can inflict a painful bite on a human if that human carelessly allows it to do so. It is said that such an event is worse than a hornet sting and that the burn, or the resulting numbness, can last for several days. Fortunately, regret not death, is the only long lasting effect. I probably don’t even have to mention that this fellow also gives off a foul odor when irritated and is attracted to turpentine oil! Nice, eh?
I came upon one of these creatures in Dayton, Ohio last week. The thing was acting rather stupid when I picked it up and it appeared to be paralyzed – which allowed me to be brave. It was alive and fresh, but unable to do much about anything around it. I could theorize that it had just experienced a run-in with another Devil Horse and had experienced a bit of its own medicine, but I have no idea on that account. At any rate, this compliant bug allowed me to pose and handle it with impunity. I will not publish the picture in which I placed a tiny fiddle in its arms nor will I display the shot where it was wearing little lederhosen, but the remaining pictures are here on this blog for you to see (see below and here).
The common name of this bug comes from the armored ridge on the thorax behind the head. A series of nine cogs are aligned on a semi-circular structure that looks like a gear wheel. There is no known function for this device other than preventing anyone but the devil to ride it (although it does make it look “wheel” nasty).
Yes, in case you are wondering, the Wheel Bug can fly and it can also chirp like some sort of diabolical cricket. The sound is made by rubbing the tip of the rostrum over series of small ridges on the bottom of the thorax. There is only one generation of Wheel Bugs per year because they take around 100 days and five instars to reach maturity in the fall. Jack Frost achieves the ultimate victory over the seasoned adults and the population overwinters in the egg stage.
Now, for all its wonderful nastiness, remember that this critter is beneficial. By feasting on damaging crop pests it serves us well. It may be devilish but its not satanic.