1Lecture 13:Why are arthropods successful?Goals:Assignment:Read: Chapter 23Websites:http://insects.tamu.edu/fieldguide/glossary.htm http://www.hollowtop.com/finl_html/finl.html http://www.ag.ohio-state.edu/~ohioline/hyg-fact/2000/2160.html http://www.antcolony.org/Army_ants.htm http://www-micro.msb.le.ac.uk/224/Parasitol.html http://www.uky.edu/Agriculture/Entomology/ythfacts/bugfood/bugfood.htm http://www.aloha.net/~smgon/triloclass.htm http://www.ucmp.berkeley.edu/diapsids/dinosaur.html http://www.ucmp.berkeley.edu/arthropoda/arthropoda.htmlhttp://www3.sk.sympatico.ca/robss/overview_htm.html http://www.earthlife.net/insects/anatomy.html http://www.earthlife.net/insects/six01.html http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/mi/toc.htm http://www.biophotos.com/whitten/specimens.html1. Define success2. Compare insects to other living organisms, understand what insect adaptations have contributed to their success3. Relate methods of attaining success to the human raceBiological ClassificationKingdom, Phylum, Class, Order, Family, Genus, SpeciesBinomial Nomenclature Leptinotarsa decemlineataPhylum Arthropoda6. Bilateral symmetry5. Open circulatory system2. Segmented body3. Jointed appendages7. Sexual Reproduction1. Exoskeleton4. Double ventral nerve cordCrustacea Sow Bug, Lobster (26,000) Aquatic, Land .2mm-200cm Class Common Name Environment SizeMerostomata Horseshoe Crab (5) Aquatic 3-60mmPycnogonida Sea Spider (500) Aquatic Marine 05 -70cm Pauropoda None (380) Soil and Leaf Mold 5-20mmSymphyla None (120) Soil and Leaf Mold 2-10mmInsecta Insects (1,000,000) Aquatic, Land, Air .1mm-25cmDiplopoda Millipede (8000) Terrestrial .1-100cmChilopoda Centipede (3,000) Terrestrial .1-100cmClasses of Arthropoda Class Insecta6. Unique biology1. Three Body Regions2. Three pairs of legs3. Most groups have functional wings4. One pair of antennae5. Tracheae respiratory system2Criteria for measuring success2. Current diversity1. Historically successful3. Environmental impactHistorically Successful1. Trilobites – 600x106 ago, fossils = hard exoskeletonHistorically Successful2. Dinosaurs – 230x106ago, first terrestrial eggDied out 65 x 106years agoHistorically Successful3. Brachiopods - hard shells, diverse forms, Been around 545 x 106 yearsHistorically Successful3. Insects -· Oldest fossils 400 x 106years old· These fossils are already well developed· Hard to find good insect fossils0100000200000300000400000500000600000700000800000insectsplantsnon-insect arthropodsmulluscsfungiProtozoaalgaemammalsNumber of described speciesOnly4,000!Tale of the TapeCurrent Diversity3Environmental ImpactInsects have important human impacts as well:• Transmit disease to us, our crops and our domesticated animals• Feed on the same things we like to eat• $$: Pollination, silk, dyes, FOOD!Insects can be found in almost every ecosystem on earthInsects are vital components of food webs1. Insects are arguably the most successful group of animals alive3. What about mammals?!Weight? size?2. One-celled organisms may rival insects in number, butit’s hard to tellSuccess? Life history strategies: The Tortoise vs. the hare1. The Tortoise•High survival rate, parental care, extended individual life, offspring training2. The Hare•Short lives, small size, high reproduction offsets high mortalityInsect adaptations that contribute to success 1. Exoskeleton2. Jointed Appendages3. Wings4. Size5. Metamorphosis6. Ability to escape adverse conditions7. Methods of Reproduction8. Short generation time9. Specialization10. Methods of solving the water problem· Overlapping chitin plates --like a suit of armor· Attachment formusclesExoskeleton-Look ma, no bones!· Protects from damage andwater lossJointed appendagesUsually specialized for the insect’s lifestyleRunning, jumping, grasping, swimming, digging4Wings•Insects have been flying for over 250 million years!•Give an advantage over non-flying organisms.17 mmSize matters:Even the largest insects are small•Easier to hide•Need less food•Easier to disperseWhy aren’t insects gigantic?Insects Limited By:1. Respiratory system- Spiracles- Trachea- Air sacs2. Musculo-skeletal systemhttp://ask.yahoo.com/ask/20011220.htmlLargest Insect ever:Meganeurahttp://www.uky.edu/Agriculture/Entomology/ythfacts/bugfun/trivia.htmMetamorphosis•Allows one organism to utilize multiple habitats• Or to become more specializedDefense!!•Flying away•Scaring away•Brute forceMonarchPoisonousViceroyNon-poisonous•Hiding in plain sightDiapause- A period of slow development and metabolism- Usually due to adverse weather: cold, lack of water, etc.Aestival diapause -summerHibernal diapause - winter5Methods of solving the water problem•Metabolic water•Condense water from the air•Conserve water by excreting pellets of uric acid, rather than urea•Wax layers in cuticleMethods of reproductionApis melliferaThe honey beeAphidsDragonfliesTiger BeetlesShort generation timeThe insect with the shortest known generation time is the apple grain aphid (Rhopalosiphum prunifoliae/fitchii), which can bear live young only 4.7 days after being born. Other kinds of aphids are almost as prolific, bearing live young anywhere from five to seven days after being born. Such rapid-breeding aphids are parthenogenetic. They are so prolific that when they are born they already carry the embryos of their first children.Allows rapid adaptationSpecializationEntomophagyMan eating BugsProverbs VI: 6Go to the ant, thou sluggard; consider her ways, and be
View Full Document