An instar (/ˈɪnstɑːr/ⓘ, from the Latin īnstar 'form, likeness') is a developmental stage of arthropods, such as insects, between each moult (ecdysis), until sexual maturity is reached.[1] Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width. After shedding their exoskeleton (moulting), the juvenile arthropods continue in their life cycle until they either pupate or moult again. The instar period of growth is fixed; however, in some insects, like the salvinia stem-borer moth, the number of instars depends on early larval nutrition.[2] Some arthropods can continue to moult after sexual maturity, but the stages between these subsequent moults are generally not called instars.
Imperial moth (Eacles imperialis) development from egg to pupa, showing all the different instars
For most insect species, an instar is the developmental stage of the larval forms of holometabolous (complete metamorphism) or nymphal forms of hemimetabolous (incomplete metamorphism) insects, but an instar can be any developmental stage including pupa or imago (the adult, which does not moult in insects).
The number of instars an insect undergoes often depends on the species and the environmental conditions, as described for a number of species of Lepidoptera. However, it is believed[by whom?] that the number of instars can be physiologically constant per species in some insect orders, as for example Diptera and Hymenoptera. The number of larval instars is not directly related to speed of development. For instance, environmental conditions may dramatically affect the developmental rates of species and still have no impact on the number of larval instars. As examples, lower temperatures and lower humidity often slow the rate of development and that may have an effect on how many molts an insect will undergo – an example of this is seen in the lepidopteran tobacco budworm.[3] On the other hand, temperature affects the development rates of a number of hymenopterans without affecting numbers of instars or larval morphology, as observed in the ensign wasp[4][5] and in the red imported fire ant.[6][7] The number of larval instars in ants has been the subject of a number of recent investigations,[8] and no instance of temperature-related variation in numbers of instars has yet been recorded.[9]
Referencesedit
The dictionary definition of instar at Wiktionary
^Allaby, Michael: A Dictionary of Ecology, page 234. Oxford University Press, US, 2006.
^Knopf, K. W.; Habeck, D. H. (1 June 1976). "Life History and Biology of Samea multiplicalis". Environmental Entomology. 5 (3): 539–542. doi:10.1093/ee/5.3.539.
^Fox, Eduardo Gonçalves Paterson; Solis, Daniel Russ; Rossi, Mônica Lanzoni; Eizemberg, Roberto; Taveira, Luiz Pilize; Bressan-Nascimento, Suzete (June 2012). "The preimaginal stages of the ensign wasp Evania appendigaster (Hymenoptera, Evaniidae), a cockroach egg predator". Invertebrate Biology. 131 (2): 133–143. doi:10.1111/j.1744-7410.2012.00261.x.
^Bressan-Nascimento, S.; Fox, E.G.P.; Pilizi, L.G.T. (February 2010). "Effects of different temperatures on the life history of Evania appendigaster L. (Hymenoptera: Evaniidae), a solitary oothecal parasitoid of Periplaneta americana L. (Dictyoptera: Blattidae)". Biological Control. 52 (2): 104–109. doi:10.1016/j.biocontrol.2009.10.005.
^Porter, Sanford D. (1988). "Impact of temperature on colony growth and developmental rates of the ant, Solenopsis invicta". Journal of Insect Physiology. 34 (12): 1127–1133. doi:10.1016/0022-1910(88)90215-6.
^Fox, Eduardo Gonçalves Paterson; Solis, Daniel Russ; Rossi, Mônica Lanzoni; Delabie, Jacques Hubert Charles; de Souza, Rodrigo Fernando; Bueno, Odair Correa (2012). "Comparative Immature Morphology of Brazilian Fire Ants (Hymenoptera: Formicidae: Solenopsis)". Psyche: A Journal of Entomology. 2012: 1–10. doi:10.1155/2012/183284. hdl:11449/73193.
^Fox, Eduardo G. P.; Smith, Adrian A.; Gibson, Joshua C.; Solis, Daniel R. [UNESP (1 October 2017). "Larvae of trap jaw ants, Odontomachus LATREILLE, 1804 (Hymenoptera: Formicidae): morphology and biological notes". Myrmecological News: 17–28. hdl:11449/163472.
^Russ Solis, Daniel; Gonçalves Paterson Fox, Eduardo; Mayumi Kato, Luciane; Massuretti de jesus, Carlos; Teruyoshi Yabuki, Antonio; Eugênia de Carvalho Campos, Ana; Correa Bueno, Odair (March 2010). "Morphological Description of the Immatures of the Ant". Journal of Insect Science. 10 (15): 15. doi:10.1673/031.010.1501. PMC3388976. PMID 20575746.
February 15, 2024
instar, instar, ɑːr, from, latin, īnstar, form, likeness, developmental, stage, arthropods, such, insects, between, each, moult, ecdysis, until, sexual, maturity, reached, arthropods, must, shed, exoskeleton, order, grow, assume, form, differences, between, in. An instar ˈ ɪ n s t ɑːr from the Latin instar form likeness is a developmental stage of arthropods such as insects between each moult ecdysis until sexual maturity is reached 1 Arthropods must shed the exoskeleton in order to grow or assume a new form Differences between instars can often be seen in altered body proportions colors patterns changes in the number of body segments or head width After shedding their exoskeleton moulting the juvenile arthropods continue in their life cycle until they either pupate or moult again The instar period of growth is fixed however in some insects like the salvinia stem borer moth the number of instars depends on early larval nutrition 2 Some arthropods can continue to moult after sexual maturity but the stages between these subsequent moults are generally not called instars Imperial moth Eacles imperialis development from egg to pupa showing all the different instarsFor most insect species an instar is the developmental stage of the larval forms of holometabolous complete metamorphism or nymphal forms of hemimetabolous incomplete metamorphism insects but an instar can be any developmental stage including pupa or imago the adult which does not moult in insects Two instars of a caterpillar of Papilio polytesThe number of instars an insect undergoes often depends on the species and the environmental conditions as described for a number of species of Lepidoptera However it is believed by whom that the number of instars can be physiologically constant per species in some insect orders as for example Diptera and Hymenoptera The number of larval instars is not directly related to speed of development For instance environmental conditions may dramatically affect the developmental rates of species and still have no impact on the number of larval instars As examples lower temperatures and lower humidity often slow the rate of development and that may have an effect on how many molts an insect will undergo an example of this is seen in the lepidopteran tobacco budworm 3 On the other hand temperature affects the development rates of a number of hymenopterans without affecting numbers of instars or larval morphology as observed in the ensign wasp 4 5 and in the red imported fire ant 6 7 The number of larval instars in ants has been the subject of a number of recent investigations 8 and no instance of temperature related variation in numbers of instars has yet been recorded 9 References edit nbsp The dictionary definition of instar at Wiktionary Allaby Michael A Dictionary of Ecology page 234 Oxford University Press US 2006 Knopf K W Habeck D H 1 June 1976 Life History and Biology of Samea multiplicalis Environmental Entomology 5 3 539 542 doi 10 1093 ee 5 3 539 tobacco budworm Heliothis virescens Fabricius entnemdept ufl edu Retrieved 2017 11 09 Fox Eduardo Goncalves Paterson Solis Daniel Russ Rossi Monica Lanzoni Eizemberg Roberto Taveira Luiz Pilize Bressan Nascimento Suzete June 2012 The preimaginal stages of the ensign wasp Evania appendigaster Hymenoptera Evaniidae a cockroach egg predator Invertebrate Biology 131 2 133 143 doi 10 1111 j 1744 7410 2012 00261 x Bressan Nascimento S Fox E G P Pilizi L G T February 2010 Effects of different temperatures on the life history of Evania appendigaster L Hymenoptera Evaniidae a solitary oothecal parasitoid of Periplaneta americana L Dictyoptera Blattidae Biological Control 52 2 104 109 doi 10 1016 j biocontrol 2009 10 005 Porter Sanford D 1988 Impact of temperature on colony growth and developmental rates of the ant Solenopsis invicta Journal of Insect Physiology 34 12 1127 1133 doi 10 1016 0022 1910 88 90215 6 Fox Eduardo Goncalves Paterson Solis Daniel Russ Rossi Monica Lanzoni Delabie Jacques Hubert Charles de Souza Rodrigo Fernando Bueno Odair Correa 2012 Comparative Immature Morphology of Brazilian Fire Ants Hymenoptera Formicidae Solenopsis Psyche A Journal of Entomology 2012 1 10 doi 10 1155 2012 183284 hdl 11449 73193 Fox Eduardo G P Smith Adrian A Gibson Joshua C Solis Daniel R UNESP 1 October 2017 Larvae of trap jaw ants Odontomachus LATREILLE 1804 Hymenoptera Formicidae morphology and biological notes Myrmecological News 17 28 hdl 11449 163472 Russ Solis Daniel Goncalves Paterson Fox Eduardo Mayumi Kato Luciane Massuretti de jesus Carlos Teruyoshi Yabuki Antonio Eugenia de Carvalho Campos Ana Correa Bueno Odair March 2010 Morphological Description of the Immatures of the Ant Journal of Insect Science 10 15 15 doi 10 1673 031 010 1501 PMC 3388976 PMID 20575746 Retrieved from https en wikipedia org w index php title Instar amp oldid 1193782268, wikipedia, wiki, book, books, library,
