Phloeodes diabolicus

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Phloeodes diabolicus
Phloeodes diabolicus.jpg
Phloeodes diabolicus, adult
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Zopheridae
Subfamily: Zopherinae
Tribe: Zopherini
Genus: Phloeodes
Species:
P. diabolicus
Binomial name
Phloeodes diabolicus
(LeConte, 1851)
Synonyms

Nosoderma diabolicum, Noserus diabolicus

The diabolical ironclad beetle (Phloeodes diabolicus) is a beetle in the Phloeodes genus. It is native to the California Floristic Province in the states of California and Baja California, where it is believed to eat fungi growing under rotting tree bark. [1] It is flightless and has a remarkably long adult lifespan of eight years, [2] compared to the weeks or months of most adult beetle lifespans. [3]

Contents

This beetle is noted for its durability. Its thick, densely layered and interlocking elytra, connected to the ventral cuticle by complex lateral support structures, are able to support a maximum force of 149 newtons, approximately equal to the force exerted by 15 kilograms or 33.069 lbs. [2]

Taxonomy

This species was named for and initially categorized taxonomically by John LeConte. When this species was first identified in the 1800s it was classified as a member of the Nosoderma genus, as were all of what were later re-classified as Phloeodes. The genus Noserus was also described by LeCont during the 1800s but is later made synonymous with Phloeodes in 1999, as it was determined that Phloeodes diabolicus and Phloedes (Noserus) plicatus, both key species in their genera, belong in the same genus. The entire genus was moved from Tenebrionidae to Zopheridae . [4] Multiple other species, such as P. latipennis, that were initially identified by a few specimens were later made synonymous with Phloeodes diabolicus starting in 1936 and continuing until 2006. Individual differences in taxonomic classification continue, including the entire genus Phloeodes being absorbed into Nosoderma (Verodes) but as of 2008 the genus Phloeodes has been restored and Phloedes diabolicus is classified within it. [1]

Ecology and behavior

Phloeodes diabolicus shares a range with Phloeodes plicatus , a reproductively isolated sister species. [5] Their range encompasses California, portions of southern Oregon, and Baja California. Like other Zopherini these insects are holometabolous and well adapted to wood boring, particularly in the larval stage showing a larger thorax and smaller legs than non-wood boring beetles. [6] These beetles are believed to be non-specific decomposers eating rotten wood from many trees and shrubs and the fungi that grow upon them, however, Phloeodes diabolicus is noted to be found most frequently underneath the bark of decomposing oak trees and believed to prefer white rot fungi as a food source. This species is flightless with a fused shell theorized to have evolved for protection from crushing and evaporative moisture loss over its long lifespan of approximately eight years. [3] This allows it to survive in drier climates and resist predation by birds and lizards without being able to fly away from them. [7]

Other commonalities with the rest of its associated family include a tendency to play dead when threatened and the ability to go long periods without food or water. Unlike other species in its family the waxy secreted coating that normally prevents moisture loss is believed to also serve a function in sexual attraction as in Phloeodes diabolicus this secretion is a masculine secondary sex characteristic. [1]

Shell structure

Pinned specimens Phloeodes diabolicus variation sjh.jpg
Pinned specimens

The flattened shape and low-to-the-ground profile of the diabolical ironclad beetle, in addition to its tough exoskeleton, makes it extremely hard to crush. The structure of the procuticle allows for focused compressive forces to be distributed evenly across the beetle's body. Because of the exoskeleton's toughness, collectors find it extremely difficult to pin specimens. The beetles cannot be mounted normally using stainless steel pins; rather, a hole must be drilled in the shell for the pin to be inserted. [8]

A jigsaw-like layering of multiple scales of different sizes, ranging from microscopic to visible sizes, provides exceptional mechanical strength to the beetle's appendages. In the beetle's procuticle, polysaccharide α-chitin combines with proteins to form fibers within each layer. These fibers are twisted and stacked upon each other, creating a "helicoid" arrangement and forming laminated structures. This formation allows for a strong, energy-absorbent and tolerant exoskeleton. The exoskeleton is able to deflect, twist, and arrest crack propagation between each layer. Compositional analysis has found that the microstructure of the beetle's exoskeleton is protein-rich and contains no inorganic structures (common in crustacean exoskeletons), while also containing a thicker endocuticle than other insects. [9]

There are two main areas that allow the skeleton to endure such forces as much as 39,000 times its own body weight. The first is the connection between the hardened elytra: they are locked in place with a zipper-like connection, which increases the exoskeleton's strength and ability to resist pressure but prevents the beetle from opening its wings to fly. The back of the beetle is not interlocked in the same way, allowing the bottom halves to slide past each other, providing flexibility to absorb squishing compression. The second area is the puzzle-like design that runs the length of the back connecting the left and right side. Protrusions called blades fit together like jigsaw pieces, glued together by proteins aiding in damage resistance. The connection allows the blades to absorb impacts without snapping. The protection allows the beetle to be almost predator proof, denying most species the ability to break the shell. [10]

The structure of its shell has inspired efforts to design similar materials and joints for use in submillimeter engineering. [11]

Related Research Articles

<span class="mw-page-title-main">Tenebrionoidea</span> Superfamily of beetles

The Tenebrionoidea are a very large and diverse superfamily of beetles. It generally corresponds to the Heteromera of earlier authors.

<span class="mw-page-title-main">Zopheridae</span> Family of beetles

Zopheridae is a family of beetles belonging to Tenebrionoidea. It has grown considerably in recent years as the members of two other families have been included within its circumscription; these former families are the Monommatidae and the Colydiidae, which are now both included in the Zopheridae as subfamilies or even as tribe of subfamily Zopherinae. Some authors accept up to six subfamilies here, while others merge all except the Colydiinae into the Zopherinae.

<span class="mw-page-title-main">Zopherinae</span> Subfamily of beetles

Zopherinae is a subfamily of beetles, commonly known as ironclad beetles. Together with the subfamily Usechinae, they have been treated historically as a family, but have recently been joined by several additional taxa, making the Zopheridae a much larger composite family, and the Zopherinae are now only a small component within it, consisting of seven genera in the tribe Zopherini and one, Phellopsis in its own tribe (Phellopsini).

<i>Zopherus concolor</i> Species of beetle

Zopherus concolor is a species of ironclad beetle in the family Zopheridae. It is found in North America.

The genus Nosoderma includes 28 species of ironclad beetles from the Americas, including some common and widely distributed species placed in the former genus Phloeodes.

<i>Eleodes</i> Genus of beetles

Eleodes is a genus of darkling beetles, in the family Tenebrionidae. They are endemic to western North America ranging from southern Canada to central Mexico with many species found along the Mexico-United States border. Some species have been introduced to Colombia. The name pinacate is Mexican Spanish, derived from the Nahuatl (Aztec) name for the insect, pinacatl, which translates as "black beetle".

<span class="mw-page-title-main">Ciidae</span> Family of beetles

The minute tree-fungus beetles, family Ciidae, are a sizeable group of beetles which inhabit Polyporales bracket fungi or coarse woody debris. Most numerous in warmer regions, they are nonetheless widespread and a considerable number of species occur as far polewards as Scandinavia for example.

<span class="mw-page-title-main">Opatrini</span> Tribe of beetles

Opatrini is a tribe of darkling beetles (Tenebrionidae) in the subfamily Tenebrioninae.

Trachelostenus is a genus of darkling beetles in the family Tenebrionidae. It is native to the Valdivian forests of Chile, and has at least two species, T. inaequalis (Solier) and T. fascicularis (Philipp). It was historically considered the only member of the family Trachelostenidae, but a 2015 study sunk the genus into the tenebrionid subfamily Tenebrioninae.

<i>Zopherus</i> Genus of beetles

Zopherus is a genus of beetles comprising 19 species. They live in the Americas and are adapted to wood-boring.

<i>Strongylium</i> Genus of beetles

Strongylium is a genus of darkling beetles in the family Tenebrionidae. It is one of the largest genera in the family and its subfamily Stenochiinae, with more than 1,400 known species which occur widely in the tropics and subtropics of the Old and New World. More than 300 species are native to the neotropics.

<i>Capnochroa</i> Genus of beetles

Capnochroa is a genus of comb-clawed beetles in the family Tenebrionidae. There are at least two described species in Capnochroa.

Zopherus elegans is a species of ironclad beetle in the family Zopheridae. It is found in North America.

Zopherus granicollis is a species of ironclad beetle in the family Zopheridae. It is found in Central America and North America.

Xerolinus is a genus of darkling beetle. It consists of approximately thirty species found in the West Indies. Michael A. Ivie and Charles J. Hart named and circumscribed the genus in 2016.

<span class="mw-page-title-main">Lagriinae</span> Subfamily of beetles

Lagriinae is a subfamily of long-jointed beetles in the family Tenebrionidae. There are more than 270 genera in Lagriinae, grouped into 11 tribes.

<i>Coelocnemis</i> Genus of beetles

Coelocnemis is a genus of darkling beetles in the family Tenebrionidae. There are about seven described species in Coelocnemis, found mainly in western Canada, western United States, and Mexico.

<span class="mw-page-title-main">Blaptinae</span> Subfamily of darkling beetles

Blaptinae is a subfamily of darkling beetles in the family Tenebrionidae. There are around 300 genera in Blaptinae, divided into 7 tribes.

<i>Tarphius floresensis</i> Species of beetle

Tarphius floresensis is a beetle species in the family Zopheridae endemic to Flores Island (Azores). It is commonly named as an iron-clad beetle in English or Escaravelho-cascudo-da-mata in Portuguese. The genus Tarphius is evolutionarily old species to Azores.

<i>Nyctoporis carinata</i> Species of beetle

Nyctoporis carinata, also known as the flightless darkling beetle because both sexes lack wings, is a species of beetle native to central and Southern California. They are found in leaf litter and rocky debris. Preliminary genetic analysis suggests that Nyctoporis carinata and Nyctoporis vandykei may in fact be synonymous species.

References

  1. 1 2 3 Foley, Ian A.; Ivie, Michael A. (2008-11-10). "A phylogenetic analysis of the tribe Zopherini with a review of the species and generic classification (Coleoptera: Zopheridae)". Zootaxa. 1928 (1). doi:10.11646/zootaxa.1928.1.1. ISSN   1175-5334.
  2. 1 2 "Even a car can't kill this beetle. Here's why". Science. Retrieved 21 October 2020.
  3. 1 2 magazine, Davide Castelvecchi,Nature. "This Beetle's Stab-Proof Exoskeleton Makes It Almost Indestructible". Scientific American. Retrieved 2020-11-30.{{cite web}}: CS1 maint: multiple names: authors list (link)
  4. Bousquet, Yves; Thomas, Donald B.; Bouchard, Patrice; Smith, Aaron D.; Aalbu, Rolf L.; Johnston, M. Andrew; Steiner Jr., Warren E. (2018-01-15). "Catalogue of Tenebrionidae (Coleoptera) of North America". ZooKeys (728): 1–455. Bibcode:2018ZooK..728....1B. doi: 10.3897/zookeys.728.20602 . ISSN   1313-2970. PMC   5799738 . PMID   29416389.
  5. Polihronakis, Maxi; Caterino, Michael S (2010). "Contrasting patterns of phylogeographic relationships in sympatric sister species of ironclad beetles (Zopheridae: Phloeodes spp.) in California's Transverse Ranges". BMC Evolutionary Biology. 10 (1): 195. Bibcode:2010BMCEE..10..195P. doi: 10.1186/1471-2148-10-195 . ISSN   1471-2148. PMC   2904329 . PMID   20573263.
  6. FOLEY, IAN A.; IVIE, MICHAEL A. (2008-01-25). "A revision of the genus Phellopsis LeConte (Coleoptera: Zopheridae)". Zootaxa. 1689 (1). doi:10.11646/zootaxa.1689.1.1. ISSN   1175-5334.
  7. "Why the diabolical ironclad beetle is nearly impossible to squish | Science News". 2020-10-21. Retrieved 2024-05-30.
  8. Machemer, Theresa. "The Secrets of the Diabolical Ironclad Beetle's Almost Unsquishable Strength". Smithsonian Magazine. Retrieved 2020-11-29.
  9. Chen, Po-Yu (October 2020). "Diabolical ironclad beetles inspire tougher joints for engineering applications". Nature. 586 (7830): 502–504. Bibcode:2020Natur.586..502C. doi: 10.1038/d41586-020-02840-1 . PMID   33087908.
  10. "The diabolical ironclad beetle can survive getting run over by a car. Here's how". Science News. 2020-10-21. Retrieved 2020-11-29.
  11. Chen, Po-Yu (2020-10-22). "Diabolical ironclad beetles inspire tougher joints for engineering applications". Nature. 586 (7830): 502–504. Bibcode:2020Natur.586..502C. doi:10.1038/d41586-020-02840-1. ISSN   0028-0836. PMID   33087908.