Wings Lock Together

close up photograph of a black beetle on a white and peach rock

Biological Strategy

Darkling beetles

AskNature Team

Image: Carla Kishinami / Flickr / CC BY NC ND - Creative Commons Attribution + Noncommercial + NoDerivatives

Manage Shear

The effect of shear stress on a living system is parallel internal surfaces sliding past each other. Slippage occurs in parallel with the force. Think about holding two wooden boards on top of each other and sliding one to the right and the other to the left. This may be easy until you add glue, which increases their shear strength and makes them harder or impossible to slide. Shear can occur in solids, liquids, and gases. Living systems must increase their shear strength to overcome these types of forces. For example, darkling beetles lock their wings together in flight to prevent lateral movement by using many small hairs on each wing. These hairs interlock to provide shear strength, just as two hair brushes put together would be difficult to slide past each other.

Search this Function

Insects

Class Insecta (“an insect”): Flies, ants, beetles, cockroaches, fleas, dragonflies

Insects are the most abundant arthropods—they make up 90% of the animals in the phylum. They’re found everywhere on earth except the deep ocean, and scientists estimate there are millions of insects not yet described. Most live on land, but many live in freshwater or saltwater marshes for part of their life cycles. Insects have three distinct body sections: a head, which has specialized mouthparts, a thorax, which has jointed legs, and an abdomen. They have well-developed nervous and sensory systems, and are the only invertebrate that can fly, thanks to their lightweight exoskeletons and small size.

Search this Living System

Wings of darkling beetles lock to prevent lateral movement due to interlocking hairs on the forewing surface and the body.

A team of researchers led by Stanislav Gorb studied the frictional surfaces of the forewing-to-body locking mechanism in tenebrionid beetles. They observed that, in beetles, the system responsible for fixing forewings (elytra) to the body consists of 1) several macrostructures located between thorax and body and between the right and left elytra, and 2) interlocking fields of cuticle protuberances known as microtrichia. The team focused on the latter, defining the microtrichia of 13 fields in terms of length, width, density, and directionality. The team found that microtrichia of different fields varied in length, width, and shape. Microtrichia of a single field were usually oriented in one direction; this appeared to prevent shifting while the locking mechanism was employed. Epidermal secretions were thought to aid microtrichia in sliding during locking and unlocking of the two surfaces. (Courtesy of the Biomimicry Guild)

Image: Stanislav Gorb / Gorb, S. N. (1999) 'Ultrastructure of the thoracic dorso-medial field (TDM) in the elytra-to-body arresting mechanism in Tenebrionid Beetles (Coleoptera:Tenebrionidae)', Journal of Morphology, Volume 240, issue 2, pp.101-113. /

Shows the structure of the microtrichia (MT) of a tenebrionid beetle.

Image: Hans Hillewaert /

Last Updated September 14, 2016

References

Journal article

Analysis of Preload-Dependent Reversible Mechanical Interlocking Using Beetle-Inspired Wing Locking Device

Langmuir | 13/12/2011 | Changhyun Pang, Daeshik Kang, Tae-il Kim, Kahp-Yang Suh

embedly preview

Reference

Journal article

Ultrastructure of the thoracic dorso-medial field (TDM) in the elytra-to-body arresting mechanism in Tenebrionid Beetles (Coleoptera: Tenebrionidae)

Journal of Morphology | 14/11/2004 | Stanislav N. Gorb

embedly preview

AskNature