Editing Beetle (section)

===Tolerance of extreme environments===
[[File:Stenocara gracilipes.jpg|thumb|The fogstand beetle of the [[Namib Desert]], ''[[Stenocara gracilipes]]'', is able to survive by [[fog collection|collecting water from fog]] on its back.]]
{{Further|Insect thermoregulation|Insect winter ecology}}

About 90% of beetle species enter a period of adult [[diapause]], a quiet phase with reduced metabolism to tide unfavourable environmental conditions. Adult diapause is the most common form of diapause in Coleoptera. To endure the period without food (often lasting many months) adults prepare by accumulating reserves of lipids, glycogen, proteins and other substances needed for resistance to future hazardous changes of environmental conditions. This diapause is induced by signals heralding the arrival of the unfavourable season; usually the cue is [[photoperiodic]]. Short (decreasing) day length serves as a signal of approaching winter and induces winter diapause (hibernation).<ref>{{cite journal |last1=Hodek |first1=Ivo |title=Review Article: Adult diapause in Coleoptera |journal=Psyche: A Journal of Entomology |volume=2012 |pages=1–10 |date=2012 |doi=10.1155/2012/249081 |doi-access=free }}</ref> A study of hibernation in the Arctic beetle ''[[Pterostichus brevicornis]]'' showed that the body fat levels of adults were highest in autumn with the [[alimentary canal]] filled with food, but empty by the end of January. This loss of body fat was a gradual process, occurring in combination with dehydration.<ref>{{cite journal |title=Hibernation in the Arctic beetle, ''Pterostichus brevicornis'', in Alaska |author1=Kaufmann, T. |date=1971 |journal=Journal of the Kansas Entomological Society |volume=44 |issue=1 |pages=81–92}}</ref>

All insects are [[poikilotherm]]ic,<ref name='Outline'>{{cite book |author1=Gullan, P. J. |author2=Cranston, P. S. |date=1994 |title=The Insects: An Outline of Entomology |publisher=Chapman and Hall |isbn=978-0-412-49360-7 |pages=103–104}}</ref> so the ability of a few beetles to live in extreme environments depends on their resilience to unusually high or low temperatures. The [[bark beetle]] ''[[Pityogenes chalcographus]]'' can survive {{gaps|−39|°C}} whilst overwintering beneath tree bark;<ref>{{cite journal |author1=Lombadero, Maria J. |author2=Ayres, Matthew P. |author3=Ayres, Bruce D. |author4=Reeve, John D. |title=Cold tolerance of four species of bark beetle (Coleoptera: Scolytidae) in North America |journal=Environmental Ecology |volume=29 |issue=3 |date=2000 |pages=421–432 |url=http://www.dartmouth.edu/~mpayres/pubs/Fina.Cold.pdf |archive-url=https://web.archive.org/web/20070417144045/http://www.dartmouth.edu/~mpayres/pubs/Fina.Cold.pdf |archive-date=2007-04-17 |url-status=live}}</ref> the Alaskan beetle ''[[Cucujus]] clavipes puniceus'' is able to withstand {{gaps|−58|°C}}; its larvae may survive {{gaps|−100|°C}}.<ref>{{cite journal |author1=Sformo, T. |author2=Walters, K. |author3=Jeannet, K. |author4=Wowk, B. |author5=Fahy, G. M. |author6=Barnes, B. M. |author7=Duman, J. G. |title=Deep supercooling, vitrification and limited survival to −100°C in the Alaskan beetle ''Cucujus clavipes puniceus'' (Coleoptera: Cucujidae) larvae |journal=[[Journal of Experimental Biology]] |date=2010 |volume=213 |issue=3 |pages=502–509 |doi=10.1242/jeb.035758 |pmid=20086136|doi-access=free }}</ref> At these low temperatures, the formation of ice crystals in internal fluids is the biggest threat to survival to beetles, but this is prevented through the production of antifreeze proteins that stop water molecules from grouping together. The low temperatures experienced by ''Cucujus clavipes'' can be survived through their deliberate dehydration in conjunction with the antifreeze proteins. This concentrates the antifreezes several fold.<ref>{{cite news |url=https://www.bbc.co.uk/nature/21923937 |title=The life of extremophiles: Surviving in hostile habitats |last1=Brooks |first1=Christopher |date=2013-03-26 |publisher=BBC Nature |access-date=2017-03-16}}</ref> The [[hemolymph]] of the mealworm beetle ''[[Tenebrio molitor]]'' contains several [[antifreeze protein]]s.<ref>{{cite journal |author1=Graham, L. A |author2=Liou, Y. C. |author3=Walker, V. K. |author4=Davies, P. L. |title=Hyperactive antifreeze protein from beetles |journal=[[Nature (journal)|Nature]] |volume=388 |issue=6644 |pages=727–728 |date=August 1997 |doi=10.1038/41908 |quote=The yellow mealworm beetle, ''Tenebrio molitor'', contains a family of small Cys-rich and Thr-rich thermal hysteresis proteins that depress the hemolymph freezing point below the melting point by as much as 5.58°C(ΔT=thermal hysteresis). Thermal hysteresis protein expression was evaluated throughout development and after exposure to altered environmental conditions. |pmid=9285581 |bibcode=1997Natur.388..727G|s2cid=205029622 |doi-access=free }}</ref> The Alaskan beetle ''[[Upis ceramboides]]'' can survive −60&nbsp;°C: its [[cryoprotectant]]s are [[xylomannan]], a molecule consisting of a [[sugar]] bound to a [[fatty acid]],<ref>{{cite journal |author1=Walters, K. R. Jr |author2=Serianni, A. S. |author3=Sformo, T. |author4=Barnes, B. M. |author5=Duman, J. G. |title=A nonprotein thermal hysteresis-producing xylomannan antifreeze in the freeze-tolerant Alaskan beetle Upis ceramboides |journal=[[PNAS]] |volume=106 |issue=48| year=2009 |pages= 20210–20215 |doi=10.1073/pnas.0909872106 |pmid=19934038 |pmc=2787118|bibcode=2009PNAS..10620210W |doi-access=free }}</ref> and the sugar-alcohol, [[threitol]].<ref>{{cite journal| title=Cryoprotectant biosynthesis and the selective accumulation of threitol in the freeze-tolerant Alaskan beetle, ''Upis ceramboides'' |author1=Walters, K. R. Jr.|author2=Pan, Q. |author3=Serianni, A. S. |author4=Duman, J. G. | journal=[[Journal of Biological Chemistry]] |year=2009 |volume= 284 |issue=25 | pages=16822–16831 | doi=10.1074/jbc.M109.013870 | pmid=19403530 | pmc=2719318|doi-access=free }}</ref>

Conversely, desert dwelling beetles are adapted to tolerate high temperatures. For example, the [[Tenebrionid]] beetle ''[[Onymacris rugatipennis]]'' can withstand {{gaps|50|°C}}.<ref>{{cite journal |author=Edney, E. B. |date=1971 |title=The body temperature of tenebrionid beetles in the Namib desert of southern Africa |journal=[[Journal of Experimental Biology]] |volume=55 |pages=253–272 |doi=10.1242/jeb.55.1.253 |url=http://jeb.biologists.org/content/jexbio/55/1/253.full.pdf |archive-url=https://web.archive.org/web/20170211080953/http://jeb.biologists.org/content/jexbio/55/1/253.full.pdf |archive-date=2017-02-11 |url-status=live}}</ref> Tiger beetles in hot, sandy areas are often whitish (for example, ''[[Habroscelimorpha dorsalis]]''), to reflect more heat than a darker color would. These beetles also exhibits behavioural adaptions to tolerate the heat: they are able to stand erect on their tarsi to hold their bodies away from the hot ground, seek shade, and turn to face the sun so that only the front parts of their heads are directly exposed.<ref>{{cite journal|doi=10.1093/aesa/83.5.911 |title=Seasonal activity and thermoregulatory behavior of ''Cicindela patruela'' (Coleoptera: Cicindelidae) |journal=Annals of the Entomological Society of America |volume=83 |issue=5 |pages=911–915 |year=1990 |last1=Knisley |first1=C. B. |last2=Schultz |first2=T. D. |last3=Hasewinkel |first3=T. H. }}</ref>

The fogstand beetle of the [[Namib Desert]], ''[[Stenocara gracilipes]]'', is able to [[fog collection|collect water from fog]], as its elytra have a textured surface combining [[hydrophilic]] (water-loving) bumps and waxy, [[hydrophobic]] troughs. The beetle faces the early morning breeze, holding up its abdomen; droplets condense on the elytra and run along ridges towards their mouthparts. Similar adaptations are found in several other Namib desert beetles such as ''[[Onymacris unguicularis]]''.<ref>{{Cite journal| doi = 10.1038/35102108| volume = 414| issue = 6859| pages = 33–34| last1 = Parker| first1 = Andrew R.| last2 = Lawrence| first2 = Chris R.| title = Water capture by a desert beetle| journal = Nature| date = 2001-11-01| pmid=11689930| bibcode = 2001Natur.414...33P| s2cid = 34785113}}</ref>

Some terrestrial beetles that exploit shoreline and floodplain habitats have physiological adaptations for surviving floods. In the event of flooding, adult beetles may be mobile enough to move away from flooding, but larvae and pupa often cannot. Adults of ''[[Cicindela togata]]'' are unable to survive immersion in water, but larvae are able to survive a prolonged period, up to 6 days, of [[Hypoxia (environmental)|anoxia]] during floods. Anoxia tolerance in the larvae may have been sustained by switching to anaerobic metabolic pathways or by reducing metabolic rate.<ref>{{cite journal |author1=Hoback, W. Wyatt |author2=Stanley, David W. |author3=Higley, Leon G. |author4=Barnhart, M. Christopher |title=Survival of immersion and anoxia by larval tiger beetles, ''Cicindela togata'' |journal=The American Midland Naturalist |volume=140 |issue=1 |pages=27–33 |doi=10.1674/0003-0031(1998)140[0027:SOIAAB]2.0.CO;2|year=1998 |s2cid=86163282 }}</ref> Anoxia tolerance in the adult carabid beetle ''[[Pelophilia borealis]]'' was tested in laboratory conditions and it was found that they could survive a continuous period of up to 127 days in an atmosphere of 99.9% nitrogen at 0&nbsp;°C.<ref>{{cite journal |title=Anaerobiosis in the overwintering beetle ''Pelophila borealis'' |author1=Conradi-Larsen, Else-Margrete |author2=Sømme, Lauritz |date=1973 |journal=Nature |volume=245 |issue=5425 |pages=388–390 |doi=10.1038/245388a0|bibcode=1973Natur.245..388C |s2cid=4288059 }}</ref>