Investigation of hindwing folding in ladybird beetles by artificial elytron transplantation and microcomputed tomography

Abstract

Ladybird beetles are high-mobility insects and explore broad areas by switching between walking and flying. Their excellent wing transformation systems enabling this lifestyle are expected to provide large potential for engineering applications. However, the mechanism behind the folding of their hindwings remains unclear. The reason is that ladybird beetles close the elytra ahead of wing folding, preventing the observation of detailed processes occurring under the elytra. In the present study, artificial transparent elytra were transplanted on living ladybird beetles, thereby enabling us to observe the detailed wing-folding processes. The result revealed that in addition to the abdominal movements mentioned in previous studies, the edge and ventral surface of the elytra, as well as characteristic shaped veins, play important roles in wing folding. The structures of the wing frames enabling this folding process and detailed 3D shape of the hindwing were investigated using microcomputed tomography. The results showed that the tape spring-like elastic frame plays an important role in the wing transformation mechanism. Compared with other beetles, hindwings in ladybird beetles are characterized by two seemingly incompatible properties: (i) the wing rigidity with relatively thick veins and (ii) the compactness in stored shapes with complex crease patterns. The detailed wing-folding process revealed in this study is expected to facilitate understanding of the naturally optimized system in this excellent deployable structure.

Shape-shifting structured lattices via multimaterial 4D printing

“…Our inverse geometric design and multimaterial 4D printing method can be readily extended to other stimuli-responsive materials and different 2-dimensional (2D) and 3D cell designs to create scalable, reversible, shape-shifting structures with unprecedented complexity. 4D printing | shape shifting | multimaterial S hape-morphing structured systems are increasingly seen in a range of applications from deployable systems (1,2) and dynamic optics (3,4) to soft robotics (5,6) and frequency-shifting antennae (7), and they have led to numerous advances in their design and fabrication using various 3-dimensional (3D) and 4-dimensional (4D) printing techniques (8,9). However, to truly unleash the potential of these methods, we need to be able to program arbitrary shapes in 3 dimensions (i.e., control the metric tensor at every point in space and time), thus defining how lengths and angles change everywhere.…”

Computational analyses decipher the primordial folding coding the 3D structure of the beetle horn

“…The second is the industrial application of the discovered folding method. Good stu ng methods are in demand in industry, as the folding of insect wings [24][25][26] has already been applied to the design of folding drones 27 . The Miura-fold, developed from the Yoshimura-pattern, has also been seen in biological materials and applied to many industrial objects [28][29][30] .…”

Origami Biosystems: 3D Assembly Methods for Biomedical Applications

“…In these processes, forces derived from differential swelling of either apical or basal portions of groups of epithelial cell sheets cause spontaneous curving and folding of tissues . At a larger length scale, and as an example of a naturally occurring dynamic process, the complex folding and unfolding mechanisms of the wings of ladybird beetles are associated with complex origami crease patterns . Throughout the review, we provide examples of strain‐engineered systems associated with bending, curving, and folding in biology and nature.…”