Editing Bed bug (section)

==Description==
{{Main|Cimex lectularius|Cimex hemipterus}}
[[File:BedBugwithMeasure.jpg|thumb|An adult bed bug is about 4 to 5 mm long.]]
Bed bug infestations are primarily the result of two species of insects from genus ''Cimex'': ''Cimex lectularius'' (the common bed bug) and ''Cimex hemipterus'' (the tropical bed bug).<ref name=JAMA2009/> These insects feed exclusively on blood and, at any stage of development, may survive up to 70 days without feeding.<ref name="Parola" /> Adult ''Cimex'' are light brown to reddish-brown, flat, oval, and have no hind wings. The front wings are [[vestigial]] and reduced to pad-like structures. Adults grow to {{convert|4|-|5|mm|in|abbr=on}} long and {{convert|1.5|–|2|mm|in|abbr=on}} wide. Female common bed bugs can lay 1–10 eggs per day and 200–500 eggs in their lifetime, whereas female tropical bed bugs can lay about 50 eggs in their lifetime.<ref name="Parola" />

Bed bugs have five immature nymph life stages and a final sexually mature adult stage.<ref>{{cite web |author1=Xavier Bonnefoy |author2=Helge Kampen |author3=Kevin Sweeney |url=http://www.euro.who.int/__data/assets/pdf_file/0011/98426/E91435.pdf |title=Public Health Significance of Urban Pests |publisher=[[World Health Organization]] |page=136 |access-date=1 December 2016 |archive-date=22 February 2017 |archive-url=https://web.archive.org/web/20170222111554/http://www.euro.who.int/__data/assets/pdf_file/0011/98426/E91435.pdf |url-status=dead }}</ref> Bed bugs need at least one blood meal in order to advance to the next stage of development.<ref name="Parola"/> They shed their skins through [[ecdysis]] at each stage, discarding their outer exoskeleton.<ref name="Shukla 2009 73">{{cite book |title=Economic Zoology |last1=Shukla |last2=Upadhyaya |edition=4th |year=2009 |page=73 |publisher=Rastogi |isbn=978-81-7133-876-4 }}</ref> Newly hatched [[Nymph (biology)|nymphs]] are translucent, lighter in color, and become browner as they [[ecdysis|moult]] and reach [[sexual maturity|maturity]]. Bed bugs may be mistaken for other insects, such as [[booklice]], small [[cockroach]]es, or [[Dermestidae|carpet beetle]]s; however, when warm and active, their movements are more ant-like, and like most other [[true bugs]], they emit a characteristic disagreeable odor when crushed.

Bed bugs are obligatory [[hematophagy|bloodsuckers]]. They have mouth parts that saw through the skin and inject saliva with [[anticoagulant]]s and painkillers. Sensitivity of humans varies from extreme allergic reaction to no reaction at all (about 20%). The bite usually produces a swelling with no red spot, but when many bugs feed on a small area, reddish spots may appear after the swelling subsides.<ref name=birc.org/> Bedbugs prefer exposed skin, preferably the face, neck, and arms of a sleeping person.

Bed bugs are attracted to their hosts primarily by [[carbon dioxide]], secondarily by warmth, and also by certain chemicals.<ref name=Kolb2009/><ref name=anderson09>{{cite journal |last1=Anderson |first1=J. F. |last2=Ferrandino |first2=F. J. |last3=McKnight |first3=S. |last4=Nolen |first4=J. |last5=Miller |first5=J. |year=2009 |title=A carbon dioxide, heat and chemical lure trap for the bed bug, ''Cimex lectularius'' |url=https://www.insect-interceptor.com/anderson.pdf |url-status=live |journal=Medical and Veterinary Entomology |volume=23 |issue=2 |pages=99–105 |doi=10.1111/j.1365-2915.2008.00790.x |pmid=19499616 |s2cid=19294476 |archive-url=https://web.archive.org/web/20170816233931/https://www.insect-interceptor.com/anderson.pdf |archive-date=16 August 2017 |access-date=27 May 2010}}</ref><ref>{{cite journal |last1=Singh |first1=Narinderpal |last2=Wang |first2=Changlu |last3=Cooper |first3=Richard |last4=Liu |first4=Chaofeng |year=2012 |title=Interactions among Carbon Dioxide, Heat, and Chemical Lures in Attracting the Bed Bug, ''Cimex lectularius'' L. (Hemiptera: Cimicidae) |journal=[[Psyche (entomology journal)|Psyche: A Journal of Entomology]] |volume=2012 |pages=1–9|doi=10.1155/2012/273613|doi-access=free}}</ref><ref>{{cite journal |last1=Wang |first1=Changlu |last2=Gibb |first2=Timothy |last3=Bennett |first3=Gary W. |last4=McKnight |first4=Susan |date=August 2009 |title=Bed bug (Heteroptera: Cimicidae) attraction to pitfall traps baited with carbon dioxide, heat, and chemical lure |journal=[[Journal of Economic Entomology]] |volume=102 |issue=4 |pages=1580–1585 |pmid=19736771 |url=https://extension.entm.purdue.edu/bedbugs/pdf/BedBugTrap.pdf |doi=10.1603/029.102.0423 |s2cid=23502680 |access-date=26 October 2018 |archive-date=20 September 2020 |archive-url=https://web.archive.org/web/20200920052533/https://extension.entm.purdue.edu/bedbugs/pdf/BedBugTrap.pdf |url-status=live }}</ref> There is strong evidence that bed bugs can respond and orient towards human odors, independently of all other host cues.<ref>{{cite journal |last1=DeVries |first1=Zachary C |last2=Saveer |first2=Ahmed M |last3=Mick |first3=Russell |author4-link=Coby Schal |last4=Schal |first4=Coby |date=2019-02-25 |title=Bed Bug (Hemiptera: Cimicidae) Attraction to Human Odors: Validation of a Two-Choice Olfactometer |url=https://academic.oup.com/jme/article/56/2/362/5174721 |journal=Journal of Medical Entomology |language=en |volume=56 |issue=2 |pages=362–367 |doi=10.1093/jme/tjy202 |issn=0022-2585 |pmc=7182910 |pmid=30423171}}</ref> ''Cimex lectularius'' feeds only every five to seven days, which suggests that it does not spend the majority of its life searching for a host. When a bed bug is starved, it leaves its shelter and searches for a host. It returns to its shelter after successful feeding or if it encounters exposure to light.<ref>{{cite journal |last1=Reis |first1=Matthew D. |last2=Miller |first2=Dini M. |year=2011 |title=Host Searching and Aggregation Activity of Recently Fed and Unfed Bed Bugs (''Cimex lectularius'' L.) |journal=Insects |volume=2 |issue=4 |pages=186–194 |pmid=26467621 |pmc=4553457 |doi=10.3390/insects2020186 |doi-access=free}}</ref> ''Cimex lectularius'' aggregate under all life stages and mating conditions. Bed bugs may choose to aggregate because of predation, resistance to desiccation, and more opportunities to find a mate. Airborne pheromones are responsible for aggregations.<ref>{{cite journal |author1=Margie Pfiester |author2=Philip G. Koehler |author3=Roberto M. Pereira |year=2009 |title=Effect of Population Structure and Size on Aggregation Behavior Of(Hemiptera: Cimicidae) |journal=Journal of Medical Entomology |volume=46 |issue=5 |pages=1015–020 |doi=10.1603/033.046.0506 |pmid=19769030 |doi-access=free}}</ref>