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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.
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Plant and Soil SciencePlant pathogens and Pest ManagementTopic: 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#anatomywww.nysaes.cornell.edu/ent/biocontrol/info/primer.html#anatomy
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/photo/aumb_2w.htm www.stephenville.tamu.edu/~fmitchel/dragonfly/photo/aumb_2w.htm
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#anatomywww.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/dragonfly/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