Insect Biology

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Insect Biology

• Topic 2042
• Aaron Gearhart

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Biology of Insects

• This lecture will go over the following topics
• Insect Body
• Head
• Thorax
• abdomen
• Insect Life Cycles
• No metamorphosis
• Gradual metamorphosis
• Incomplete metamorphosis
• Complete metamorphosis

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Body of an Insect

• Divided into three parts
• Head
• Thorax
• Abdomen
• Segmentation allows for efficiency since each
  segment is specialized for a different function

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The Head

• Contains the following parts
• Eyes Simple or Compound
• Anennae used for smelling or feeling
• Mouthparts for sucking or chewing

www.earthlife.net/insects/six.html
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Mouthparts

• Almost infinite variations
• Mouthparts are often used to determine type of
  control that will be most effective for a
  specific insect
• Examples
• Fly has a sponge type mouth
• Assasin bug Has a spear or needle type mouth
• Grasshopper Has a chewing mouth
• Some butterflys Have a long hose for sucking
  nectar

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Thorax

• The locomotive segment of an insect
• Contains wings and legs
• Of course insects have three pairs of legs for a
  total of.6
• Insects may have
• 0 wings ants, lice, mites
• 1 pair of wings flys, true bugs
• 2 pairs of wings wasps, bees

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Abdomen

• Contains the following
• Digestive organs
• Reproductive organs
• Respiratory organs
• Excretory organs
• Abdomen can change shape depending on how much it
  ate or if it has eggs.

http//www.denniskunkel.com/PublicHtml/WANTED/BODI
ES/IndexBodies.html
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Lifecycles of the Insect

• No metamorphosis
• Gradual metamorphosis
• Incomplete metamorphosis
• Complete metamorphosis

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No Metamorphosis

• These insects emerge from the eggs looking
  exactly like the adult but smaller
• Primitive insects like the silverfish are
  examples of this
• Also known as ametabolous

http//www.life.uiuc.edu/Entomology/insectgifs/thy
sanura.gif
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Gradual Metamorphosis

• Similar to no metamorphosis but the youngster
  coming out of the egg is slightly different from
  the adult
• Examples are grasshoppers and crickets

http//www.ent.iastate.edu/
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Incomplete metamorphosis

• These insects change from egg -gt nymph -gt adult
• After their last molt these insects rapidly
  change to adult
• Some examples would be dragonflies
• Also termed hemimetabolous

http//stephenville.tamu.edu/fmitchel/dragonfly/p
hoto/cw_aes1.htm
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Complete metamorphosis

• Goes through four distinct stages
• Egg
• Larvae
• Pupa
• Adult

http//www.geocities.com/pchew_brisbane/wanderer.h
tm
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Questions or Comments?
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