Structural Design Variations in Beetle Elytra

Abstract

Beetles typically use their protective wing coverings or elytra to shield their membranous hindwings from the environment. Elytra in some terrestrial species have evolved a greater protective role capable of shielding the organism from powerful antagonistic predators. The structure-function relationships of these biological composites identify how architectural and chemical variations of the cuticle are tuned to create light-weight, impact resistant composites. Specifically, the elytral structures of a tree dwelling beetle capable of flight, Trypoxylus dichotomus, and a terrestrial beetle incapable of flight, Phloeodes diabolicus, are compared to understand how their varied environmental needs forged the elytra to facilitate fight or resist fatal predator strikes. Mechanical and microstructural analysis reveals P. diabolicus has a harder, stiffer elytra that incorporate through-thickness fibers to resist greater mechanical stresses imposed by bending and puncture. Conversely, the elytra of T. dichotomus have a compliant structure with large voids that facilitates localized deformation. Variations in flexural strength and puncture resistance remain attributed to P. diabolicus possessing a thicker cuticle with a greater degree of cross-linking and an increased amount of endocuticular layers. These findings may provide useful insight into the design and manufacturing of composite materials for use in light-weight or energy-absorbing applications.

Microstructure and Hydrophobicity of the External Surface of a Sonoran Desert Beetle

“…It prevents water from evaporating and shields the insect body from mechanical stresses. It is known that it contains proteins, chitin, and aliphatic compounds [ 20 , 21 , 22 ]. In order to have an idea of the chemical composition of the elytra surface of the studied Sonoran beetles, we performed Fourier Transform Infrared spectroscopy (FT-IR) experiments.…”

Impact of carbofurans on sweet corn pest predators: A study of good agroecosystem practices

“…Elitra is orange in color, coupled with a black spot-like pattern that varies from individual to individual. Elitra on E. admirabilis looks dull and not shiny (Rivera et al, 2021).…”

Nanoarchitected Tough Biological Composites from Assembled Chitinous Scaffolds

“…(h) Interply penetrating chitin microfibers (false colored yellow) within the helicoidal structure. Images were reproduced with permission from ref , copyright 2012 AAAS; ref , copyright 2020 Springer Nature; ref , copyright 2020 Springer Nature; ref , copyright 2016 Wiley; ref , copyright 2018 Elsevier; and ref , copyright 2021 Wiley.…”

“…We recently investigated two species of beetles from different habitats and described how variations in their exoskeletal architecture and composition allow them to thrive in their respective environments . We focused on the elytra from two species of beetles that branched approximately 250 million years ago: , Trypoxylus dichotomus (known as the rhinoceros beetle), a tree-dwelling and thus flight capable beetle inhabiting East Asia, and Phloeodes diabolicus (named the diabolical ironclad beetle), a terrestrial fungivore incapable of flight residing on the western coast of North America. , For P. diabolicus , this inability to actuate its elytra has resulted in a structurally robust cuticle capable of withstanding predator strikes (Figure e).…”