How wasp and bee stinger designs help deliver the pain

October 08, 2018

COLUMBUS, Ohio - Next time you're stung by a wasp or a honeybee, consider the elegantly designed stinger that caused you so much pain.

In a new study, researchers found that the stingers of the two species are about five times softer at the tip than at the base to make it easier to pierce your skin. The stingers are harder closer to the insect's body so they don't bend too much, or break, as you yelp in agony.

"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," said Bharat Bhushan, Ohio Eminent Scholar and Howard D. Winbigler Professor of mechanical engineering at The Ohio State University.

"If you felt the pain right away, you would react and swat the insect away before it finished injecting its venom."

Bhushan conducted the study with colleagues from the Indian Institute of Technology (IIT), led by Navin Kumar, associate professor of mechanical engineering. It was published October 8, 2018 in Nature Scientific Reports.

The scientists collected wasps (Vespula vulgaris) and honeybees (Apis cerana) near IIT. They examined the stinger in unprecedented detail using sophisticated 3D imaging, a tool to measure hardness and elasticity, and numerical modelling to calculate the most efficient penetration angle.

"When you really study these stingers, you see how elegant and mechanically durable they are," said Bhushan, who realizes "elegant" is probably not the first word a person thinks of after being stung.

"Other words might come to mind first," he said with a laugh. "But when you're looking at it from an engineer's perspective, the stingers really are elegantly designed."

The stingers of bees and wasps are different in some ways. The wasps' are curved, for instance, while those of the bees are straight. But they have much in common.

In both species, the stingers have two serrated lancets (think needles) that project from the end of the stinger. The lancets move back and forth to pierce the skin. A channel between the two delivers venom.

Imaging showed the stingers had hollow spaces to reduce weight while maintaining strength.

"It is a clever design to optimize the mechanical properties of the stingers without being too heavy," Bhushan said.

In addition to being softer at the tip, the study showed that the stingers were about seven times more elastic at the tip than at the base.

"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," he said.

Findings suggested that bees and wasps probably wouldn't sting straight down into a person's skin. The researchers calculated that the most efficient angle for penetration would be 6 degrees for the honeybee stinger and 10 degrees for the wasp stinger. These are the angles that would best maintain the structural stability of the stingers.

In a similar previous study, Bhushan and his colleagues investigated the proboscis of mosquitos, the part that pierces skin to draw blood. Why the fascination with insects that pierce our skin?

As an engineer who has made a career of designing products inspired by nature, Bhushan has a practical reason. He believes scientists can design a better, painless microneedle for medical purposes by mimicking some of the design elements of bees, wasps and mosquitos.

For example, he thinks needles should be designed to be softer at the tip to lessen the pain at insertion - just like the insects' pointy parts. Health care practitioners could even use this study's findings on the best angle for stinger insertion to guide their use of a new microneedle.

"We're trying to put what we learned about insect stingers to productive use by imagining the design of a better microneedle," Bhushan said.
Other co-authors of the study, all at IIT, are Rakesh Das, Ram Naresh Yadav, Praveer Sihota and Piyush Uniyal.

Contact: Bharat Bhushan, 614-292-0651;

Ohio State University

Related Pain Articles from Brightsurf:

Pain researchers get a common language to describe pain
Pain researchers around the world have agreed to classify pain in the mouth, jaw and face according to the same system.

It's not just a pain in the head -- facial pain can be a symptom of headaches too
A new study finds that up to 10% of people with headaches also have facial pain.

New opioid speeds up recovery without increasing pain sensitivity or risk of chronic pain
A new type of non-addictive opioid developed by researchers at Tulane University and the Southeast Louisiana Veterans Health Care System accelerates recovery time from pain compared to morphine without increasing pain sensitivity, according to a new study published in the Journal of Neuroinflammation.

The insular cortex processes pain and drives learning from pain
Neuroscientists at EPFL have discovered an area of the brain, the insular cortex, that processes painful experiences and thereby drives learning from aversive events.

Pain, pain go away: new tools improve students' experience of school-based vaccines
Researchers at the University of Toronto and The Hospital for Sick Children (SickKids) have teamed up with educators, public health practitioners and grade seven students in Ontario to develop and implement a new approach to delivering school-based vaccines that improves student experience.

Pain sensitization increases risk of persistent knee pain
Becoming more sensitive to pain, or pain sensitization, is an important risk factor for developing persistent knee pain in osteoarthritis (OA), according to a new study by researchers from the Université de Montréal (UdeM) School of Rehabilitation and Hôpital Maisonneuve Rosemont Research Centre (CRHMR) in collaboration with researchers at Boston University School of Medicine (BUSM).

Becoming more sensitive to pain increases the risk of knee pain not going away
A new study by researchers in Montreal and Boston looks at the role that pain plays in osteoarthritis, a disease that affects over 300 million adults worldwide.

Pain disruption therapy treats source of chronic back pain
People with treatment-resistant back pain may get significant and lasting relief with dorsal root ganglion (DRG) stimulation therapy, an innovative treatment that short-circuits pain, suggests a study presented at the ANESTHESIOLOGY® 2018 annual meeting.

Sugar pills relieve pain for chronic pain patients
Someday doctors may prescribe sugar pills for certain chronic pain patients based on their brain anatomy and psychology.

Peripheral nerve block provides some with long-lasting pain relief for severe facial pain
A new study has shown that use of peripheral nerve blocks in the treatment of Trigeminal Neuralgia (TGN) may produce long-term pain relief.

Read More: Pain News and Pain Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to