Plant and Soil Science Plant pathogens and Pest Management Topic: Entomology insect Biology 2042

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Plant and Soil SciencePlant pathogens and Pest
ManagementTopic Entomology/ insect Biology
(2042)

• Brian Sobecki

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Insect Facts

• Study of insects is called Entomology
• Insects have lived on earth for 250 million
  years.
• There are an estimated 1,000,000 species of
  insect on our planet.
• Insects can be helpful, neutral, or harmful to
  humans

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Biology of Insects

• The body of an insect is divided into three parts
  the Head, Thorax, and Abdomen.
• The word insect come from the Latin word
  insectum which means cut into.
• The segmented body gives them the advantage of
  movement and activity.

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Biology of Insects

• Segmentation also provides efficiency. Each body
  segment is specialized into functions such as
• Securing food
• Locomotion
• Reproduction

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The Insect Body

• The Head (contains antennae and Mouth parts)
• Eyes are either simple or Compound.
• Antennae are used for smelling and feeling.
• Mouth parts are for either sucking or chewing.
• Mouth parts are the most variable of all insect
  characteristics.
• They are often used to determine the type of
  control measures that will be most effective for
  a particular insects.

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The Insect Body

• The Thorax (Locomotion Segment)
• Contains the wings and legs.
• An insect may have zero, one or two pairs of
  wings.
• The thorax also has three pairs of legs.

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The Insect Body

• The Abdomen ( contains digestive, reproductive,
  respiratory and excretory organs)
• Shrinks or swells according to the state of those
  organs.
• Variations occurs when the insects eat, produces
  eggs or fills with excrement.

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Life Cycles

• The several changes that insects go through to
  reach maturity is called Metamorphosis.
• There are four variations or Metamorphosis
• A few insects have no metamorphosis.
• Insects emerge from eggs looking exactly like
  adults, except smaller
• Example Silverfish

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Life Cycles

• Some insects go through Gradual metamorphosis.
• They change shape gradually.
• Example Grasshopper and Cricket

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www.nysaes.cornell.edu/ent/biocontrol/info/primer.
htmlanatomy
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Life Cycles

• Other Insects have an incomplete metamorphosis.
• Change gradually until they reach the last stage.
• They change quickly into their last stage after
  their last molt. ( shedding of the outer layer of
  skin)
• Example Dragonfly

www.stephenville.tamu.edu/fmitchel/dragonfly/phot
o/aumb_2w.htm
www.stephenville.tamu.edu/fmitchel/dragonfly/phot
o/aumb_2w.htm
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Life Cycles

• Some have a complete metamorphosis.
• Insects go through Four stages Egg, Larvae,
  Pupa, and Adult
• None of the young stages look anything like the
  adult stage.
• Example Moths and Butterflies

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www.nysaes.cornell.edu/ent/biocontrol/info/primer.
htmlanatomy
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Life Cycles

• Understanding metamorphosis will help you better
  understand techniques of insect control.
• Egg and pupa stages are most resistant to
  chemical spray.
• The larval stage are the most destructive, but
  most vulnerable to spray.
• The adult stage is also destructive, but
  controllable.

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Pictures

• (All butterflies pictures) The Butterfly Guide,
  www.butterflies.com/guide.html
• Aeshnidea Digital Dragonflies,
  www.stephenville.tamu.edu/fmitchel/dragonfly/phot
  o/aumb_2w.htm
• Insect Biology and Ecology a primer Biological
  control A guide to natural enemies in North
  America Weeden, Shelton, and Hoffmann
  www.nysaes.cornell.edu/ent/biocontrol/info/primer.
  htmlanatomy