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Grylloblattidae

{{Short description|Family of insects}}

{{redirect|Rock crawler|the vehicle used in the off-road discipline of the same name|Rock crawling}}

{{Automatic taxobox

| image = Galloisiana nipponensis 2.jpg

| image_caption = Galloisiana nipponensis

| image2 = Grylloblattidae (cropped).jpg

| image2_caption = Specimen of Grylloblatta in lateral view

| fossil_range =

| oldest_fossil =

| taxon = Grylloblattidae

| authority = E. M. Walker, 1914

| display_parents = 2

| subdivision_ranks = Genera

| subdivision = Galloisiana

Grylloblatta

Grylloblattella

Grylloblattina

Namkungia

}}

Grylloblattidae, commonly known as the icebugs or ice crawlers, is a family of extremophile (psychrophile) and wingless insects that live in the cold on top of mountains and the edges of glaciers. It is the only member of Grylloblattodea, which is generally considered an order. Alternatively, Grylloblattodea, along with Mantophasmatodea (rock crawlers), have been ranked as suborders of the order Notoptera.{{cite journal|last1=Arillo|first1=A.|last2=Engel|first2=M.S.|year=2006|title=Rock crawlers in Baltic amber (Notoptera: Mantophasmatodea)|journal=American Museum Novitates|volume=3539|pages=1–10|url=https://www.biodiversitylibrary.org/page/59821931}} Grylloblattids are wingless insects mostly less than 3 cm long, with a head resembling that of a cockroach, with long antennae and having elongated cerci arising from the tip of their abdomen. They cannot tolerate warmth (most species will die at 10 °C) and many species have small distribution ranges.

Overview

Grylloblattids, ice crawlers or icebugs puzzled the scientists who discovered them in 1914, E.M. Walker and T.B. Kurata; the first species named was Grylloblatta campodeiformis, which means "cricket-cockroach shaped like a Campodea" (a kind of two-pronged bristletail). Most are nocturnal and appear to feed on detritus. They have long antennae (23–45 segments) and long cerci (5–8 segments), but no wings. Their eyes are either missing or reduced and they have no ocelli (simple eyes).{{cite book |last1=Richards |first1=O. W. |last2=Davies |first2=R. G. |title=Imms' General Textbook of Entomology |chapter=Grylloblattodea |publisher=Springer Netherlands |date=1977 |page=533 |doi=10.1007/978-94-011-6516-7_9 |isbn=978-0-412-15230-6 }} Their closest living relatives are the recently discovered Mantophasmatodea.{{cite journal |author=Stephen L. Cameron, Stephen C. Barker & Michael F. Whiting |date=2006 |title=Mitochondrial genomics and the new insect order Mantophasmatodea |journal=Molecular Phylogenetics and Evolution |volume=38 |pages=274–279 |doi=10.1016/j.ympev.2005.09.020 |pmid=16321547 |issue=1}} Most species are less than 3 cm long, the largest being Namkungia magnus.{{cite journal|doi=10.5281/zenodo.174644|year=2006|last1=Kim|first1=Byung-Woo|last2=Lee|first2=Woncheol|title=Redescription of the Largest Ice Bug, Namkungia Magnus Com. Nov. (Grylloblattodea, Grylloblattidae) from Korea|journal=Zootaxa|volume=1359|pages=57–66}}

The family has its own order, Grylloblattodea (sometimes considered a suborder of Notoptera). It contains 5 genera and about 34 extant species.{{cite book|author=Terry L. Erwin |date=1997 |chapter=Biodiversity at its utmost: tropical forest beetles |pages=[https://archive.org/details/biodiversityiiun00reak/page/27 27–40] |editor=Marjorie L. Reaka-Kudla, Don E. Wilson & Edward O. Wilson |title=Biodiversity II |url=https://archive.org/details/biodiversityiiun00reak |url-access=registration |publisher=Joseph Henry Press |location=Washington, D.C. |isbn=978-0-309-05584-0}}{{cite journal| author=Zhang, Z.-Q.| title=Phylum Arthropoda von Siebold, 1848 In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness | journal=Zootaxa| volume=3148| date=2011| pages=99–103| url=http://mapress.com/zootaxa/2011/f/zt03148p103.pdf| doi=10.11646/zootaxa.3148.1.14 }}

Most species have restricted distributions and small populations and with increased warming their habitats are threatened, making them endangered. In North America some species like Grylloblatta barberi and G. oregonensis are known from single sites.{{cite journal|doi=10.1111/syen.12052|title=Current status of the systematics and evolutionary biology of Grylloblattidae (Grylloblattodea)|journal=Systematic Entomology|volume=39|issue=2|pages=197–204|year=2014|last1=Schoville|first1=Sean D|doi-access=free}}

Habitat and distribution

Grylloblattodea are nocturnal extremophiles typically found in leaf litter and under stones in extremely cold environments, usually at higher elevations. They are known to inhabit cold temperate forests to glaciers and the edges of ice sheets. Their optimal living temperature is between {{convert|1|-|4|C|F}}. They can be killed at colder temperatures due to ice formation in the body, so when the temperature drops below their optimal range they survive by living under snow pack near the soil.{{cite book|title=Evolution of the Insects|author=David Grimaldi, Michael S. Engel |date=2005|chapter=Polyneoptera: Grylloblattodea: The Ice Crawlers |pages= 222–224 |publisher=Cambridge University Press| location=New York City |isbn=9780521821490}} They have a very narrow range of temperatures that they prefer and cannot withstand high temperatures; many species are killed when the temperature rises about 5 °C above their optimal temperature. They move in response to the seasons so as to maintain an optimal temperature in their foraging habitat.{{Cite journal|last1=Schoville|first1=Sean D.|last2=Slatyer|first2=Rachel A.|last3=Bergdahl|first3=James C.|last4=Valdez|first4=Glenda A.|date=2015|title=Conserved and narrow temperature limits in alpine insects: Thermal tolerance and supercooling points of the ice-crawlers, Grylloblatta (Insecta: Grylloblattodea: Grylloblattidae)|journal=Journal of Insect Physiology|volume=78|pages=55–61|doi=10.1016/j.jinsphys.2015.04.014|pmid=25956197|issn=0022-1910}}

Grylloblattidae are patchily distributed in glaciers, caves, montane environments, and occasionally lower-elevation forests in western North America, East Asia (Korea and Japan), and Central Asia (Siberia, China, and Kazakhstan). They are predicted to occur in several other mountain chains in Asia, including parts of the Himalayas.{{cite journal |last1=Bai |first1=Ming |last2=Jarvis |first2=Karl |last3=Wang |first3=Shu-Yong |last4=Song |first4=Ke-Qing |last5=Wang |first5=Yan-Ping |last6=Wang |first6=Zhi-Liang |last7=Li |first7=Wen-Zhu |last8=Wang |first8=Wei |last9=Yang |first9=Xing-Ke |year=2010 |title=A Second New Species of Ice Crawlers from China (Insecta: Grylloblattodea), with Thorax Evolution and the Prediction of Potential Distribution |journal=PLOS ONE |volume=5 |issue=9 |pages=e12850 |bibcode=2010PLoSO...512850B |doi=10.1371/journal.pone.0012850 |pmc=2943926 |pmid=20877572 |doi-access=free}}

Diet

They are omnivorous, but feed primarily on dead arthropods and carrion. When arthropod carcasses are scarce, they subsist on plant material.

Evolution

Grylloblattidae is generally thought to have emerged from within the "Grylloblattida", a poorly defined group of extinct winged insects that first appeared in the Late Carboniferous,{{Cite journal |last1=Cawood |first1=Rebecca |last2=Nel |first2=Andre |last3=Garrouste |first3=Romain |last4=Moyo |first4=Sydney |last5=Villet |first5=Martin H. |last6=Prevec |first6=Rose |date=2022-06-29 |title=The first 'Grylloblattida' of the family Liomopteridae from the Middle Permian in the Onder Karoo, South Africa (Insecta: Polyneoptera) |url=http://sciencepress.mnhn.fr/fr/periodiques/comptes-rendus-palevol/21/22 |journal=Comptes Rendus Palevol |volume=21 |issue=22 |pages=451–461 |doi=10.5852/cr-palevol2022v21a22 |s2cid=250157791 |issn=1777-571X|doi-access=free }} over 300 million years ago. The winged Aristovia from the mid-Cretaceous Burmese amber of Myanmar, around 100 million years ago is thought to be closely related to modern Grylloblattidae due to its very similar mouthparts.{{Cite journal |last=Cui |first=Yingying |last2=Bardin |first2=Jérémie |last3=Wipfler |first3=Benjamin |last4=Demers‐Potvin |first4=Alexandre |last5=Bai |first5=Ming |last6=Tong |first6=Yi‐Jie |last7=Chen |first7=Grace Nuoxi |last8=Chen |first8=Huarong |last9=Zhao |first9=Zhen‐Ya |last10=Ren |first10=Dong |last11=Béthoux |first11=Olivier |date=2024-03-07 |title=A winged relative of ice‐crawlers in amber bridges the cryptic extant Xenonomia and a rich fossil record |url=https://onlinelibrary.wiley.com/doi/10.1111/1744-7917.13338 |journal=Insect Science |language=en |doi=10.1111/1744-7917.13338 |issn=1672-9609}}

Taxonomy

List of Grylloblattodea genera and species along with their type localities:{{cite journal |last1=Wipfler |first1=Benjamin |last2=Bai |first2=Ming |last3=Schoville |first3=Sean |last4=Dallai |first4=Romano |last5=Uchifune |first5=Toshiki |last6=Machida |first6=Ryuichiro |last7=Cui |first7=Yingying |last8=Beutel |first8=Rolf G. |title=Ice Crawlers (Grylloblattodea) – the history of the investigation of a highly unusual group of insects |journal=Journal of Insect Biodiversity |volume=2 |issue=2 |date=2014-01-20 |issn=2147-7612 |doi=10.12976/jib/2014.2.2 |pages=1–25 |s2cid=84729486 |url=https://www.mapress.com/jib/article/view/2014.2.2 |access-date=2021-12-12|doi-access=free }}

In total, there are 35 extant species and 6 extant genera described as of 2023.

References

{{Reflist|30em}}

External links

  • {{Commons category-inline}}
  • {{Wikispecies-inline}}
  • [https://www.youtube.com/watch?v=FbR-dT83zKM Video of a walking grylloblattid] in the Three Sisters Wilderness of Oregon

{{Orders of Insects}}

{{Notoptera}}

{{Taxonbar|from1=Q13582699|from2=Q796470}}

Category:Insect families

Category:Psychrophiles

Category:Extant Triassic first appearances

Category:Taxa named by Edmund Murton Walker