World Library  
Flag as Inappropriate
Email this Article

Holometabolism

Article Id: WHEBN0001638622
Reproduction Date:

Title: Holometabolism  
Author: World Heritage Encyclopedia
Language: English
Subject: Hypermetamorphosis, Lepidoptera, Insect, Imaginal disc, Lilioceris
Collection: Developmental Biology, Entomology
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Holometabolism

Hymenoptera holometabolism

Holometabolism, also called complete metamorphism, is a form of insect development which includes four life stages – as an embryo or egg, a larva, a pupa and an imago or adult. Holometabolism is a synapomorphic trait of all insects in the superorder Endopterygota. In some species the holometabolous life cycle prevents larvae from competing with adults because they inhabit different ecological niches. Accordingly, their morphology can be adapted to just one phase of activity, such as larvae feeding for growth and development, as opposed to adults flying for dispersal and seeking new supplies of food for their offspring. Conversely, in some insects, the adults can protect and feed the younger stages.

Contents

  • Stages 1
    • Egg 1.1
    • Larva 1.2
    • Pupa 1.3
    • Imago 1.4
  • Orders 2
  • See also 3
  • External links 4

Stages

There are four developmental stages, each with its own morphology.

Egg

The first stage is from the fertilization of the egg inside the mother until the embryo hatches. The insect starts as a single cell and then develops into the larval form before it hatches.

Larva

The second stage lasts from hatching or birth until the larva pupates. In most species this mobile stage is worm-like in form. Such larvae can be one of several general varieties:

Other species however may be campodeiform (a form reminiscent of members of the genus Campodea, elongated, more or less straight, flattened, and active, with functional legs). This stage is variously adapted to gaining and accumulating the materials and energy necessary for growth and metamorphosis.

Pupa

The third stage is from pupation until eclosion. The pupae of most species hardly move at all, although the pupae of some species, such as mosquitoes, are mobile. In preparation for pupation, the larvae of many species construct a protective cocoon of silk or other material, such as its own accumulated faeces. There are three types of pupae: obtect, exarate, and coarctate. Obtect pupae are compact, with the legs and other appendages enclosed. Exarate pupae have their legs and other appendages free and extended. Coarctate pupae develop inside the larval skin. In this stage, the insect's physiology and functional structure, both internal and external, change drastically.

Imago

Adult holometabolous insects usually have wings (excepting where secondarily lost) and functioning reproductive organs. In this stage, reproduction is the top priority for queens and males.

Orders

The Orders that contain holometabolous insects are :

See also

External links

  • Metamorphosis – A remarkable change
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.