Insect Biology
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Transcript of Insect Biology
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 metamorphosisGradual metamorphosisIncomplete metamorphosisComplete 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?
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