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Insect Biology. Topic 2042 Aaron Gearhart. 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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Insect Biology Topic 2042 Aaron Gearhart
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 http://www.ent.iastate.edu/list/images.html
Body of an Insect • Divided into three parts • Head • Thorax • Abdomen Segmentation allows for efficiency since each segment is specialized for a different function
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
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
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 http://www.ent.iastate.edu/list/images.html
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/BODIES/IndexBodies.html
Lifecycles of the Insect No metamorphosis Gradual metamorphosis Incomplete metamorphosis Complete metamorphosis
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/thysanura.gif
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/
Incomplete metamorphosis • These insects change from egg -> nymph -> 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/photo/cw_aes1.htm
Complete metamorphosis • Goes through four distinct stages • Egg • Larvae • Pupa • Adult http://www.geocities.com/pchew_brisbane/wanderer.htm
Questions or Comments? http://www.ent.iastate.edu/list/images.html