Editing Caterpillar (section)

== Behavior ==
[[File:Pasture day moth caterpillar closeup.jpg|thumb|A [[pasture day moth]] caterpillar feeding on capeweed]]

Caterpillars have been called "eating machines", and eat leaves voraciously. Most species shed their [[skin]] four or five times as their bodies grow, and they eventually enter a [[pupa]]l stage before becoming adults.<ref>{{usurped|1=[https://web.archive.org/web/20130825072814/http://www.scienceprojectlab.com/monarch-butterfly.html Monarch Butterfly]}}. Scienceprojectlab.com. Retrieved on 2012-08-14.</ref> Caterpillars grow very quickly; for instance, a [[tobacco hornworm]] will increase its weight ten-thousandfold in less than twenty days. An adaptation that enables them to eat so much is a mechanism in a specialized midgut that quickly transports ions to the lumen (midgut cavity), to keep the potassium level higher in the midgut cavity than in the [[hemolymph]].<ref>{{cite journal|author1=Chamberlin, M.E. |author2=M.E. King |journal= J. Exp. Zool. |volume=280|pages=135–141|doi=10.1002/(SICI)1097-010X(19980201)280:2<135::AID-JEZ4>3.0.CO;2-P|title=Changes in midgut active ion transport and metabolism during the fifth instar of the tobacco hornworm (''Manduca sexta'')|year=1998|issue=2}}</ref>

[[File:Gypsy moth caterpillar.JPG|thumb|left| A [[spongy moth]] caterpillar]]

Most caterpillars are solely [[herbivore|herbivorous]]. Many are restricted to feeding on one species of plant, while others are polyphagous. Some, including the [[clothes moth]], feed on [[detritus]]. Some are predatory, and may prey on other species of caterpillars (e.g. Hawaiian ''[[Eupithecia]]''). Others feed on eggs of other insects, aphids, scale insects, or ant larvae. A few are parasitic on cicadas or leaf hoppers ([[Epipyropidae]]).<ref name="pierce">{{cite journal|author=Pierce, N.E.|year=1995|title=Predatory and parasitic Lepidoptera: Carnivores living on plants|url=http://images.peabody.yale.edu/lepsoc/jls/1990s/1995/1995-49(4)412-Pierce.pdf|journal=Journal of the Lepidopterists' Society|volume=49|issue=4|pages=412–453|access-date=2016-11-04|archive-date=2016-11-04|archive-url=https://web.archive.org/web/20161104141351/http://images.peabody.yale.edu/lepsoc/jls/1990s/1995/1995-49(4)412-Pierce.pdf|url-status=live}}</ref> Some Hawaiian caterpillars (''[[Hyposmocoma molluscivora]]'') use silk traps to capture snails.<ref>{{cite journal|doi=10.1126/science.1110397|pmid=16040699|year=2005|last1=Rubinoff|first1=Daniel|last2=Haines|first2=William P.|title=Web-spinning caterpillar stalks snails|volume=309|issue=5734|page=575|journal=Science|s2cid=42604851}}</ref>

Many caterpillars are nocturnal. For example, the "cutworms" (of the family [[Noctuidae]]) hide at the base of plants during the day and only feed at night.<ref>{{cite web|publisher=USGS|url=http://www.npwrc.usgs.gov/resource/insects/catnw/ecol.htm|title=Caterpillars of Pacific Northwest Forests and Woodlands|access-date=2009-03-11|archive-date=2009-05-08|archive-url=https://web.archive.org/web/20090508161254/http://www.npwrc.usgs.gov/resource/insects/catnw/ecol.htm|url-status=live}}</ref> Others, such as spongy moth (''[[Lymantria dispar]]'') larvae, change their activity patterns depending on density and larval stage, with more diurnal feeding in early instars and high densities.<ref>{{cite journal|doi=10.1111/j.1365-2311.1987.tb01005.x|title=Behaviour of late-instar gypsy moth larvae in high and low density populations|year=1987|last1=Lance|first1=D. R.|journal=Ecological Entomology|volume=12|page=267|last2=Elkinton|first2=J. S.|last3=Schwalbe|first3=C. P.|issue=3|bibcode=1987EcoEn..12..267L |s2cid=86040007|url=https://zenodo.org/record/1230605|access-date=2019-09-10|archive-date=2020-10-19|archive-url=https://web.archive.org/web/20201019124059/https://zenodo.org/record/1230605|url-status=live}}</ref>