Editing Lepidoptera (section)

== Behavior ==

=== Flight ===

Flight is an important aspect of the lives of butterflies and moths, and is used for evading predators, searching for food, and finding mates in a timely manner, as most lepidopteran species do not live long after eclosion. It is the main form of locomotion in most species. In Lepidoptera, the forewings and hindwings are mechanically coupled and flap in synchrony. Flight is anteromotoric, or being driven primarily by action of the forewings. Although lepidopteran species reportedly can still fly when their hindwings are cut off, it reduces their linear flight and turning capabilities.<ref>{{cite journal |author1=Benjamin Jantzen |author2=Thomas Eisner |date=28 July 2008 |title=Hindwings are unnecessary for flight but essential for execution of normal evasive flight in Lepidoptera|journal=[[Proceedings of the National Academy of Sciences]] |volume=105 |issue = 43 |pages=16636–16640 |pmid=18936482 |doi=10.1073/pnas.0807223105 |pmc=2575472 |bibcode = 2008PNAS..10516636J |doi-access=free }}</ref>

Lepidopteran species have to be warm, about {{convert|77|to|79|F|C}}, to fly. They depend on their body temperature being sufficiently high and since they cannot regulate it themselves, this is dependent on their environment. Butterflies living in cooler climates may use their wings to warm their bodies. They will bask in the sun, spreading out their wings so that they get maximum exposure to the sunlight. In hotter climates butterflies can easily overheat, so they are usually active only during the cooler parts of the day, early morning, late afternoon or early evening. During the heat of the day, they rest in the shade. Some larger thick-bodied moths (e.g. Sphingidae) can generate their own heat to a limited degree by vibrating their wings. The heat generated by the flight muscles warms the thorax while the temperature of the abdomen is unimportant for flight. To avoid overheating, some moths rely on hairy scales, internal air sacs, and other structures to separate the thorax and abdomen and keep the abdomen cooler.{{citation needed|date=August 2022}}

Some species of butterflies can reach fast speeds, such as the [[southern dart]], which can go as fast as {{Convert|48.4|km/h|mi/h}}. Sphingids are some of the fastest flying insects, some are capable of flying at over {{Convert|50|km/h|mi/h}}, having a wingspan of {{Convert|35-150|mm|in}}.<ref name="Capinera"/><ref>{{cite web |url=http://www.speedofanimals.com/insect |title=Speed of animals |author=Reisner, Alex |publisher=speedofanimals.com |access-date=20 February 2011 |archive-url=https://web.archive.org/web/20110225124115/http://www.speedofanimals.com/insect |archive-date=25 February 2011 |url-status=dead }}</ref> In some species, sometimes a gliding component to their flight exists. Flight occurs either as hovering, or as forward or backward motion.<ref name=autogenerated2>{{Cite book |last=Scoble |first=Malcolm |title=The Lepidoptera: Form, Function and Diversity |publisher=Oxford University Press, 1995 |pages=66–67 |isbn=978-0-19-854952-9 |url=https://books.google.com/books?id=gnpd_5iNTiwC&pg=PA66 |date=1995 |access-date=11 September 2020 |archive-date=1 June 2021 |archive-url=https://web.archive.org/web/20210601163848/https://books.google.com/books?id=gnpd_5iNTiwC&pg=PA66 |url-status=live }}</ref> In butterfly and moth species, such as [[hawk moth]]s, hovering is important as they need to maintain a certain stability over flowers when feeding on the nectar.<ref name="Capinera"/>

==== Navigation ====
{{main|Animal navigation}}
[[File:Moths attracted by floodlight.jpg|thumb|right|Long exposure image of flying moths, attracted to the floodlights]]

[[Animal navigation|Navigation]] is important to Lepidoptera species, especially for those that migrate. Butterflies, which have more species that migrate, have been shown to navigate using time-compensated sun compasses. They can see [[polarized light]], so can orient even in cloudy conditions. The polarized light in the region close to the ultraviolet spectrum is suggested to be particularly important.<ref name="Saumam">{{Cite journal |last=Sauman |first=Ivo |author2=Adriana D. Briscoe |author3=Haisun Zhu |author4=Dingding Shi |author5=Oren Froy |author6=Julia Stalleicken |author7=Quan Yuan |author8=Amy Casselman |author9=Steven M. Reppert   |date=5 May 2005 |title=Connecting the Navigational Clock to Sun Compass Input in Monarch Butterfly Brain |journal=Neuron |volume=46 |issue=3 |pages=457–467 |doi=10.1016/j.neuron.2005.03.014 |pmid=15882645|s2cid=17755509 |doi-access=free }}</ref> Most migratory butterflies are those that live in semiarid areas where breeding seasons are short.<ref name="Southwood">{{Cite journal |last=Southwood |first=T. R. E. |year=1962 |title=Migration of terrestrial arthropods in relation to habitat |journal=[[Biological Reviews]] |volume=37 |issue=2 |pages=171–211 |doi=10.1111/j.1469-185X.1962.tb01609.x|s2cid=84711127 }}</ref> The life histories of their host plants also influence the strategies of the butterflies.<ref name="Dennis">{{Cite journal |last=Dennis |first=Roger L. H.|author2=Tim G. Shreeve |author3=Henry R. Arnold |author4=David B. Roy  |date = September 2005|title=Does diet breadth control herbivorous insect distribution size? Life history and resource outlets for specialist butterflies |journal=Journal of Insect Conservation |volume=9 |issue= 3 |pages=187–200 |doi=10.1007/s10841-005-5660-x|bibcode=2005JICon...9..187D |s2cid=20605146}}</ref> Other theories include the use of landscapes. Lepidoptera may use coastal lines, mountains, and even roads to orient themselves. Above sea, the flight direction is much more accurate if the coast is still visible.<ref name="Made">{{Cite book |last=Made |first=J. G. van der|author2=Josef Blab |author3=Rudi Holzberger |author4=H. van den Bijtel  |title=Actie voor Vlinders, zo kunnen we ze redden. |publisher=Weert: M & P cop. |year=1989 |page=192|isbn=978-90-6590-303-7|language=nl}}</ref>

Many studies have also shown that moths navigate. One study showed that many moths may use the [[Earth's magnetic field]] to navigate, as a study of the [[heart and dart]] moth suggests.<ref name="heart-and-dart">{{Cite journal |last=Baker |first=R. Robin |date = February 1987|title=Integrated use of moon and magnetic compasses by the heart-and-dart moth, ''Agrotis exclamationis'' |journal=Animal Behaviour |volume=35 |issue=1 |pages=94–101 |doi=10.1016/S0003-3472(87)80214-2|s2cid=54314728 }}</ref> Another study, of the migratory behavior of the [[silver Y]], showed, even at high altitudes, the species can correct its course with changing winds, and prefers flying with favourable winds, suggesting a great sense of direction.<ref>{{Cite news |url=http://www.gre.ac.uk/pr/articles/2008news/a1537---moths |title=Scientists make compass discovery in migrating moths |last=Breen |first=Amanda |date=7 May 2008 |publisher=University of Greenwich at Medway |page=1 |access-date=9 December 2009 |url-status=dead |archive-url=https://archive.today/20120530141617/http://www.gre.ac.uk/pr/articles/2008news/a1537---moths |archive-date=30 May 2012 }}</ref><ref name="Chapman">{{Cite journal |last1=Chapman |first1=Jason W. |first2=Don R. |last2=Reynolds |first3=Henrik |last3=Mouritsen |first4=Jane K. |last4=Hill |first5=Joe R. |last5=Riley |first6=Duncan |last6=Sivell |first7=Alan D. |last7=Smith |first8=Ian P. |last8=Woiwod |date=8 April 2008 |title=Wind selection and drift compensation optimize migratory pathways in a high-flying moth |journal=Current Biology |volume=18 |issue=7 |pages=514–518 |doi=10.1016/j.cub.2008.02.080 |pmid=18394893 |bibcode=2008CBio...18..514C |s2cid=3236142 |url=https://repository.rothamsted.ac.uk/download/1b0eb17b2e2cb34d1483a5a45159f6f47d94e99744eb7b325170de28434fbdbd/117278/PIIS096098220800362X.pdf |access-date=11 September 2020 |archive-date=31 May 2021 |archive-url=https://web.archive.org/web/20210531114608/https://repository.rothamsted.ac.uk/download/1b0eb17b2e2cb34d1483a5a45159f6f47d94e99744eb7b325170de28434fbdbd/117278/PIIS096098220800362X.pdf |url-status=live }}</ref> ''[[Aphrissa statira]]'' in [[Panama]] loses its navigational capacity when exposed to a magnetic field, suggesting it uses the Earth's magnetic field.<ref>{{Cite journal |last1=Srygley |first1=Robert B.|first2=Evandro G. |last2=Oliveira |first3=Andre J. |last3=Riveros  |year=2005 |title=Experimental evidence for a magnetic sense in Neotropical migrating butterflies (Lepidoptera: Pieridae) |journal=The British Journal of Animal Behaviour |volume=71 |issue=1 |pages=183–191 |url=http://users.ox.ac.uk/~zool0206/AnimBeh06.pdf |archive-url=https://web.archive.org/web/20091104100719/http://users.ox.ac.uk/~zool0206/AnimBeh06.pdf |archive-date=4 November 2009 |doi=10.1016/j.anbehav.2005.04.013|s2cid=25203050}}</ref>

Moths exhibit a tendency to circle artificial lights repeatedly. This suggests they use a technique of [[celestial navigation]] called [[transverse orientation]]. By maintaining a constant angular relationship to a bright celestial light, such as the [[Moon]], they can fly in a straight line. Celestial objects are so far away, even after traveling great distances, the change in angle between the moth and the light source is negligible; further, the moon will always be in the upper part of the visual field or on the [[horizon]]. When a moth encounters a much closer artificial light and uses it for navigation, the angle changes noticeably after only a short distance, in addition to being often below the horizon. The moth instinctively attempts to correct by turning toward the light, causing airborne moths to come plummeting downwards, and at close range, which results in a spiral flight path that gets closer and closer to the light source.<ref>{{Cite news |url=https://www.npr.org/templates/story/story.php?storyId=12903572 |title=Why are Moths Attracted to Flame? (audio) |last1=Elliot |first1=Debbie |first2=May |last2=Berenbaum |date=18 August 2007 |publisher=National Public Radio |page=1 |access-date=12 December 2009 |archive-url=https://web.archive.org/web/20090108215236/http://www.npr.org/templates/story/story.php?storyId=12903572 |archive-date=8 January 2009 |url-status=live }}</ref> Other explanations have been suggested, such as the idea that moths may be impaired with a visual distortion called a [[Mach band]] by Henry Hsiao in 1972. He stated that they fly towards the darkest part of the sky in pursuit of safety, thus are inclined to circle ambient objects in the Mach band region.<ref>{{Cite book |last=Hsiao |first=Henry S. |title=Attraction of moths to light and to infrared radiation |publisher=San Francisco Press |year=1972|isbn=978-0-911302-21-9}}</ref>

==== Migration ====
{{Main|Lepidoptera migration}}
[[File:Monarch butterflies in Santa Cruz-11.jpg|left|thumb|[[Monarch (butterfly)|Monarch butterflies]], seen in a cluster in [[Santa Cruz, California|Santa Cruz]], [[California]], where the western population migrates for the winter]]

Lepidopteran migration is typically [[season]]al, as the insects moving to escape dry seasons or other disadvantageous conditions. Most lepidopterans that migrate are butterflies, and the distance travelled varies. Some butterflies that migrate include the [[mourning cloak]], [[painted lady]], [[American lady]], [[Vanessa atalanta|red admiral]], and the [[common buckeye]].<ref name="Dole"/>{{rp|29–30}} A notable species of moth that migrates long distances is the [[bogong moth]].<ref>{{cite journal |last1=Warrant |first1=Eric |last2=Frost |first2=Barrie |author2-link=Barrie Frost |last3=Green |first3=Ken |last4=Mouritsen |first4=Henrik |last5=Dreyer |first5=David |last6=Adden |first6=Andrea |last7=Brauburger |first7=Kristina |last8=Heinze |first8=Stanley |year=2016 |title=The Australian Bogong Moth ''Agrotis infusa'': A Long-Distance Nocturnal Navigator |journal=Frontiers in Behavioral Neuroscience |volume=10 |page=77 |doi=10.3389/fnbeh.2016.00077|pmid=27147998 |pmc=4838632 |doi-access=free }}</ref> The most well-known migrations are those of the eastern population of the [[monarch butterfly]] from Mexico to northern United States and southern Canada, a distance of about {{convert|4000|-|4800|km|abbr=on}}. Other well-known migratory species include the painted lady and several of the [[Danainae|danaine]] butterflies. Spectacular and large-scale migrations associated with the [[monsoons]] are seen in peninsular India.<ref>{{cite journal |author=Williams, C. B. |year=1927 |title=A study of butterfly migration in south India and Ceylon, based largely on records by Messrs. G. Evershed, E. E. Green, J. C. F. Fryer and W. Ormiston |journal=[[Transactions of the Royal Entomological Society of London]] |volume=75 |issue=1 |pages=1–33 |doi=10.1111/j.1365-2311.1927.tb00054.x}}</ref> Migrations have been studied in more recent times using wing tags and stable hydrogen isotopes.<ref>{{cite journal |author1=Urquhart, F. A.  |author2=N. R. Urquhart |year=1977 |title=Overwintering areas and migratory routes of the Monarch butterfly (''Danaus p. plexippus'', Lepidoptera: Danaidae) in North America, with special reference to the western population |journal=[[Canadian Entomologist]] |volume=109 |issue=12 |pages=1583–1589 |doi=10.4039/ent1091583-12|s2cid=86198255 }}</ref><ref>{{cite journal |doi=10.1073/pnas.95.26.15436 |author1=Wassenaar L. I. |author2=K. A. Hobson |year=1998 |title=Natal origins of migratory monarch butterflies at wintering colonies in Mexico: new isotopic evidence |journal=[[Proceedings of the National Academy of Sciences]] |volume=95 |issue=26 |pages=15436–15439 |pmid=9860986 |pmc=28060|bibcode = 1998PNAS...9515436W |doi-access=free }}</ref>

Moths also undertake migrations, an example being the [[Uraniidae|uraniids]]. ''[[Urania fulgens]]'' undergoes population explosions and massive migrations that may be not surpassed by any other insect in the [[Neotropic]]s. In [[Costa Rica]] and [[Panama]], the first population movements may begin in July and early August and depending on the year, may be very massive, continuing unabated for as long as five months.<ref name="Smith N. G. ">{{Cite book |last1=Smith |first1=N. G. |editor-last=Janzen |editor-first= D. H. |title=''Urania fulgens'' (Calipato Verde, Green Urania) |publisher=[[University of Chicago Press]] |location=Chicago |year=1983 |series=Costa Rican Natural History |page=816}}</ref>

=== Communication ===
[[File:Group of Melitaea athalia near Warka, Poland.PNG|thumb|Group of ''Melitaea athalia'' near [[Warka]], [[Poland]]]]
Pheromones are commonly involved in mating rituals among species, especially moths, but they are also an important aspect of other forms of communication. Usually, the pheromones are produced by either the male or the female and detected by members of the opposite sex with their antennae.<ref name=autogenerated1>{{Cite book |last=Chapman |first=R. F. |title=The Insects: Structure and Function |url=https://archive.org/details/insectsstructure0000chap |url-access=registration |quote=Insects. |edition=4 |year=1998 |publisher=Cambridge University Press |location=New York |isbn=978-0-521-57890-5 |page=[https://archive.org/details/insectsstructure0000chap/page/715 715]}}</ref> In many species, a gland between the eighth and ninth segments under the abdomen in the female produces the pheromones.<ref name="cgillott"/> Communication can also occur through stridulation, or producing sounds by rubbing various parts of the body together.<ref name="Chapman"/>

Moths are known to engage in acoustic forms of communication, most often as courtship, attracting mates using sound or vibration. Like most other insects, moths pick up these sounds using tympanic membranes in their abdomens.<ref name="communications web">{{cite web |url=http://www.cals.ncsu.edu/course/ent425/tutorial/Communication/sound.html |title=Acoustic Communication |author=Meyer, John R. |year=2006 |publisher=Department of Entomology, C State University |access-date=25 February 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110720011820/http://www.cals.ncsu.edu/course/ent425/tutorial/Communication/sound.html |archive-date=20 July 2011 }}</ref> An example is that of the [[polka-dot wasp moth]] (''Syntomeida epilais''), which produces sounds with a frequency above that normally detectable by humans (about 20&nbsp;kHz). These sounds also function as tactile communication, or communication through touch, as they stridulate, or vibrate a substrate like leaves and stems.<ref name="Sanderford"/>

Most moths lack bright colors, as many species use coloration as [[camouflage]], but butterflies engage in visual communication. Female [[cabbage butterfly|cabbage butterflies]], for example, use ultraviolet light to communicate, with scales colored in this range on the dorsal wing surface. When they fly, each down stroke of the wing creates a brief flash of ultraviolet light which the males apparently recognize as the flight signature of a potential mate. These flashes from the wings may attract several males that engage in aerial courtship displays.<ref name="communications web"/>