Editing Hypermetamorphosis (section)

==Description==
[[File:Hypermetamorphosis2.JPG|thumb|These planidia are fairly typical of certain species of parasitoid wasps, in this case the genus ''[[Perilampus]]''.]]

[[File:Hypermetamorphosis in Meloidae.JPG|thumb|Hypermetamorphosis in Meloidae. This form of planidium is a typical triungulin and feeds in its first instar. In its second instar it turns into a less triungulin-like form, and feeds again. It then turns into the Scarabaeoid form for two or more instars, depending on species. After that it adopts pre-pupal forms, pupates, and finally emerges as an adult beetle.]]

[[File:Triungulin on a butterfly (5739202307).jpg|thumb|Triungulin on a butterfly. This probably is an example of [[phoresy]] rather than parasitism.]]
Hypermetamorphosis, as the term normally is used in entomology, refers to a class of variants of [[holometabolism]]. In hypermetamorphosis some larval instars are functionally and [[Morphology (biology)|morphologically]] distinct from each other.
 
The general case in holometabolous insects such as [[Fly|flies]], [[moth]]s, or [[wasp]]s, is that all larval stages look similar, growing larger as the insect matures. In hypermetamorphic insects however, at least one instar, usually the first, differs markedly from the rest. In many hypermetamorphic species, the first instars are numerous, tiny, very mobile larvae that must find their way to a food source. The general term for a mobile first instar is a [[planidium]], from the [[Ancient Greek|Greek language]] ''πλάνος'' (planos) meaning "roaming".

In typical examples the first-instar larval morphology is [[Wiktionary:campodeiform|campodeiform]] (meaning: elongated, flattened, and active, more or less resembling the morphology of hexapods in the genus ''[[Campodea]]''). There is however, considerable variety in the forms of planidia that occur in various families and orders; in the beetle family [[Meloidae]], the three-clawed planidium originally was called a triungulin, and similar planidia for example, those of the [[Strepsiptera]], may also be called triungula.

In their planidial form, many species do not feed; they first [[Ecdysis|molt]] into a form suited to eating rather than seeking out food. The second instar is completely different in appearance and behavior, often becoming grub- or maggot-like in the instars before pupation. As a rule, the instars after the first ecdysis are of more or less constant form and not highly mobile, being specialised for feeding and growth until the final larval instar metamorphoses into the pupal form.<ref name="introduction to the study of insects">{{cite book | title=Borror and Delong's Introduction to the Study of Insects| last=Triplehorn| first=Charles| date=2005| publisher=Peter Marshall}}{{page needed|date=November 2012}}</ref>

The moth family [[Gracillariidae]] is an unusual case of hypermetamorphosis in that its first few larval instars do feed, but differently to later instars. Specifically, early instars feed on plant sap (and for this reason have modified mandibles) while later instars feed on plant tissue. Furthermore, instead of becoming less mobile during the larval stage, larvae become more mobile, with early instars lacking legs while later instars possess legs.<ref>{{Cite journal |last1=Kawahara |first1=Akito Y. |last2=Plotkin |first2=David |last3=Ohshima |first3=Issei |last4=Lopez-Vaamonde |first4=Carlos |last5=Houlihan |first5=Peter R. |last6=Breinholt |first6=Jesse W. |last7=Kawakita |first7=Atsushi |last8=Xiao |first8=Lei |last9=Regier |first9=Jerome C. |last10=Davis |first10=Donald R. |last11=Kumata |first11=Tosio |last12=Sohn |first12=Jae-Cheon |last13=De Prins |first13=Jurate |last14=Mitter |first14=Charles |date=2017 |title=A molecular phylogeny and revised higher-level classification for the leaf-mining moth family Gracillariidae and its implications for larval host-use evolution |url=https://resjournals.onlinelibrary.wiley.com/doi/10.1111/syen.12210 |journal=Systematic Entomology |language=en |volume=42 |issue=1 |pages=60–81 |doi=10.1111/syen.12210 |bibcode=2017SysEn..42...60K |issn=0307-6970}}</ref>

There are examples of holometabolic species in which there are certain striking differences between the earliest instars and the later instars, though ''without'' their generally being regarded as hypermetamorphic. For example, early instars of many [[Swallowtail butterfly|Papilionidae]] are of a colour, shape and texture that suggest bird droppings; later instars that are larger and would simply stand out in such camouflage, typically become green.<ref>{{Cite journal |last1=Prudic |first1=Kathleen L. |last2=Oliver |first2=Jeffrey C. |last3=Sperling |first3=Felix A. H. |date=2007-12-04 |title=The signal environment is more important than diet or chemical specialization in the evolution of warning coloration |journal=Proceedings of the National Academy of Sciences |language=en |volume=104 |issue=49 |pages=19381–19386 |doi=10.1073/pnas.0705478104 |doi-access=free |issn=0027-8424 |pmc=2148298 |pmid=18029450}}</ref> The [[prepupa]] or last larval instar of insects ceases to feed and (in some cases) searches for a place to pupate,<ref>{{Cite web |last=Knapp |first=Sarah |date=2019-04-25 |title=Complete Metamorphosis: Definition and Examples |url=https://biologydictionary.net/complete-metamorphosis/ |access-date=2024-02-15 |website=Biology Dictionary |language=en-US}}</ref><ref>{{Cite web |title=FORENSIC ENTOMOLOGY : THE USE OF INSECTS |url=https://www.sfu.ca/~ganderso/forensicentomology.htm |access-date=2024-02-15 |website=www.sfu.ca}}</ref> but this also is not considered hypermetamorphosis.

{{multiple image
 | total_width = 230
 | image1 = Vv cm early instar.jpg
 | alt1 = An early instar of ''Papilio polytes'', resembles a bird dropping.
 | image2 = Papilio Polyetes 08062012 (1).jpg
 | alt2 = A late instar of ''Papilio polytes'' is lightly camouflaged. 
 | footer = Early instars of ''[[Papilio polytes]]'' (left) resemble a bird dropping, while the late ones (right) are too big to do so, and are simply camouflaged as a leaf. This striking coloration difference between the instars is generally not regarded as hypermetamorphosis.
}}