Butterfly Life Cycle

3 Key excerpts on "Butterfly Life Cycle"

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  eBook - ePub

  The Natural History of Moths

  • Mark Young, Lyn Wells(Authors)
  • 2010(Publication Date)
  • T & AD Poyser

    (Publisher)

  HAPTER 4 Life Cycles and Hibernation

  WHAT IS A LIFE CYCLE ?

  T HE success of any animal's life is judged by the number of offspring that it produces. Successful individuals place more copies of their genetic material in the next generation than do the unsuccessful; they are favoured by natural selection in the process of evolution. Consequently, the preoccupation of all species, including moths, is to reproduce as freely as possible and the early stages of their lives are merely devices to ensure that the reproductive stage is reached quickly. All of the specialised and intricate structures of the eggs, larvae, pupae and adults are really servants to the eggs and sperm that will combine to form the next generation.

  The life cycle of a moth represents the time-scale for development of the various stages between hatching and final reproduction. The life cycle strategy is the characteristic pattern of development of the species in relation to the external environment, which serves to complete the development effectively. The best solution is not necessarily to mature as soon as possible, for the adult moth may then be very small and will produce relatively few eggs. A larger moth, which will take longer to mature, may also contain more eggs, or the same number of larger eggs, and each species reaches a different compromise between adult size and generation time. Some have short generation times, others lay many eggs. Another compromise is the size of each egg. Large eggs have large food stores and the resultant larvae are better able to establish themselves in the environment; however, a moth can produce only a relatively small number of large eggs. Small eggs result in small and vulnerable larvae but can be carried in large numbers. The Sword-grass (Xylena exsoleta) is a large moth but lays many small eggs; some Hepialidae produce up to 18000 (Thompson and Pellmyr, 1991), whereas the Small Elephant Hawk moth (Deilephila porcellus), which is more or less the same size, lays many fewer (c.

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  Progression in Primary Science

  A Guide to the Nature and Practice of Science in Key Stages 1 and 2

  • Martin Hollins, Maggie Williams, Virginia Whitby(Authors)
  • 2013(Publication Date)
  • David Fulton Publishers

    (Publisher)

  A useful starting point for looking at life cycles is from the viewpoint of 'ourselves'. Getting children to record, in a simple form, the stages of the human life cycle not only helps to develop the idea of sequencing; but also reinforces the idea of different needs at different stages.

  Comparing our own life cycle with that of other living organisms can help to highlight a number of similarities and differences. The idea of the need for protection in the early stages of an animal's life cycle and how particular species show adaptations to this is an interesting area to explore.

  The life cycle of the butterfly or frog are often studied in schools as examples of metamorphosis, i.e. a complete change of body form during the completion of one life cycle. Both provide excellent examples of adaptation, together with areas for exploration.

  Exploring adaptive features within the life cycle of the cabbage white butterfly can raise the following questions for the different stages:

  • Egg: Where is it found? Why do you think this is a suitable place?
  • Caterpillar: Where is it found? How does it move and feed? How is it suited to its environment? Is it in danger of being eaten? Who by? Is there anything about it which helps it to survive?
  • Pupa: Where is it found? How is it protected?
  • Butterfly: Where is it found? How does it move and feed? How is it suited to its way of life?

  The same sort of pattern of discovery can be applied to the life cycle of the frog. Here, answers to questions will provide the idea of many eggs being produced to ensure survival of the species. The fact that up to a thousand eggs may be laid by a single frog gives some indication of the risks to survival. When children compare the structure, form and life style of the tadpole with that of the adult frog, they will become aware of two completely different responses to adaptation.

  A study of fruits and seeds can also help to promote children's understanding of adaptation. Children can explore the link between the variety of form and function with the overriding need for survival, The adaptations are numerous but a study of a limited number of fruits and seeds can lead to a wide range of investigations, for example exploring winged fruits such as sycamore.

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  Bugs Rule!

  An Introduction to the World of Insects

  • Whitney Cranshaw, Richard Redak(Authors)
  • 2013(Publication Date)
  • Princeton University Press

    (Publisher)

  Stoneflies (Plecoptera) are insects that have evolved the ability to fold their wings (a). In other insect orders, the forewings have been further modified so that they help cover and protect the hindwings, such as in grasshoppers (Orthoptera) (b). Photograph of the stonefly courtesy of Tom Murray. Photograph of the grasshopper by Whitney Cranshaw/Colorado State University.

  Complete metamorphosis . Among the present-day insects, at least 85% of all species have a form of development involving what is known as complete metamorphosis (chapter 4). These insects have a soft-bodied immature form (a larva), usually with very different appearance and habits from the adult (compare a caterpillar to a butterfly). Wings develop entirely internally and only during the transition stage of the pupa do adult features begin to emerge.

  Complete metamorphosis provides several ­advantages. Most obviously, it allows insects in

  immature and adult stages to specialize for different functions. The larvae of insects with complete metamorphosis often feed on different foods from the adults and spend much of their life in different environments. This prevents competition for food between adults and juveniles. Insect larvae also have better control of their development and may go into a controlled state of dormancy (diapause) or accelerate to maturation when conditions are unfavorable. Adult insects can specialize

  in egg production and dispersal. Complete metamor

  phosis was first found in the order Neuroptera, which evolved in the late Permian period. Since then, insects as diverse as beetles, wasps, fleas, and flies have evolved with this developmental pathway.

  FIGURE 4-9

  The majority of the insects now present on the planet have evolved to use complete metamorphosis in their development, beetles, flies, wasps, bees, moths, and butterflies being common examples. Insects that have complete metamorphosis, such as the cabbage white butterfly, Pieris rapae , can have an adult form (a) that is specialized for dispersal, host finding, and mating and a larval form (b) that is specialized for feeding. Photograph of the adult courtesy of David Cappaert/Michigan State University/Bugwood.org

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