Download Plant and Soil Science Plant pathogens and Pest Management

Plant and Soil Science
Plant pathogens and Pest
Management
Topic: Entomology/ insect
Biology (2042)
Brian Sobecki
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
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.
Biology of Insects
– Segmentation also provides efficiency. Each
body segment is specialized into functions such
as:
• Securing food
• Locomotion
• Reproduction
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.
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.
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.
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
Life Cycles
– Some insects go through Gradual
metamorphosis.
• They change shape gradually.
• Example: Grasshopper and Cricket
www.nysaes.cornell.edu/ent/biocontrol/info/primer.html#anatomy
Life Cycles
– Other Insects have an incomplete
metamorphosis.
www.stephenville.tamu.edu/~fmitchel/dragonf
ly/photo/aumb_2w.htm
• 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/photo/aumb_2
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
www.nysaes.cornell.edu/ent/biocontrol/info/primer.html#anatomy
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.
Pictures
• (All butterflies pictures) The Butterfly
Guide, www.butterflies.com/guide.html
• Aeshnidea; Digital Dragonflies,
www.stephenville.tamu.edu/~fmitchel/drag
onfly/photo/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.html#anatomy