Don’t get mad the next time a wasp jabs you in the arm at a picnic. Distract yourself from the searing pain by contemplating how the wasp’s stinger is precisely designed to inflict maximum hurt, scientists from The Ohio State University say.
“When you really study these stingers, you see how elegant and mechanically durable they are,” said mechanical engineering professor Bharat Bhushan in a news release. “Other words might come to mind first. But when you’re looking at it from an engineer’s perspective, the stingers really are elegantly designed.”
In an October 8 study published Monday in the journal Scientific Reports, Bhusan and other researchers used computer imagery to study what happens when a bee or wasp plunges its stinger into a helpless victim.
It’s not just morbid curiosity. The scientists said in the study the research could be useful for researchers developing special microneedles for medicine.
The scientists looked at the stingers of two insects: the common wasp and the honeybee. The insects had been collected from India, frozen and then had the stingers removed, according to the study.
The scientists then created a computer model of the stingers to examine their structures at high detail.
One thing the researchers noticed was that the stingers were much softer at the tip than toward the base. This devious design might be to trick the victim into not noticing the sting until it’s too late, Bhusan wrote.
“Wasps and bees don’t want to create too much pain to start with, and we believe the softer tip makes it less likely that you’ll notice the initial insertion,” he said. “If you felt the pain right away, you would react and swat the insect away before it finished injecting its venom.”
They found that the average wasp stinger was about 2.5 millimeters long (or about twice the width of a grain of sand), with about 1.5 millimeters of that puncturing the skin. The honeybee stinger was shorter, at about 1.6 millimeters long. The wasp stinger was also curved, while the bee stinger was not.
The stingers are made up of two smaller needles that penetrate the skin, and a hollow channel that injects venom into the bloodstream, the scientists said.
“It is a clever design to optimize the mechanical properties of the stingers without being too heavy,” Bhushan said in the news release. “The differences in hardness and rigidity along the length of the stinger helps ensure it can penetrate as deep as possible while maintaining its structure.”
So how can these painful appendages help humans?
“We’re trying to put what we learned about insect stingers to productive use by imagining the design of a better microneedle,” Bhushan wrote.
That would mean making a needle that is thinner at the tip so it requires less force to penetrate the skin, keeping pain to a low, the scientists say. Studying the angle bees choose to plunge their stingers in could also help medical professionals figure out a better way to actually give the injection, the scientists said.