Ento 2010 Final Exam Study Guide
Ento 2010 Final Exam Study Guide ENTO 2010
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Ento 2010 Final Exam Study Guide Entomology: study of insects Entomologist: one who studies insects Insect cells are very similar to human cells Kingdom-Animalia o Phylum-Arthropoda Class-Insecta Phylum Arthropoda o Arthro=jointed o Poda=foot Exoskeleton made of chitin Body composed of segments Jointed appendages Open circulatory system Bilateral symmetry Sexual reproduction Class Chilopoda o Chilo=lip o Poda=foot o Centipedes o 3,000 species one pair of legs per segment predators: eat small arthropods live in soil and humus Class Diplopoda o Diplo=two o Poda=feet o Millipedes o 8,000 species two pairs of legs per body segment feed on decaying organic matter Class Crustacea o Crust=hard; shell-like o Lobsters, crabs, shrimp o 26,000 species branched appendages aquatic marine equivalent of insects Class Arachnida o Arachne=spider o 57,000 species no antennae two body segments terrestrial carnivorous Class Insecta o In=into o Sect=cut o 1,000,000 (named) species 3 body segments head, thorax, abdomen 6 legs most adults have wings 2 antennae breathe through openings in body terrestrial or aquatic only invertebrates that can fly … “we must have agricultural chemicals. Without them the world population will starve.” –Norman Borlaug (1970) Nobel Peace Prize Insect Enemies- “The majority of insects cause destruction.” DDT use in the 1940s & 1950s: o A new way to collect insects o Add DDT to gin----happiness o A miracle chemical o Led to an “Era of Optimism” o Farmers- “when the chemical came along…you had your crop.” Pesticide: a chemical used to kill pests Pesticide: a substance used to kill pests Insecticide: substance that kills insects DDT= chlorinated hydrocarbon o Othmar Zeidler o Synthesized DDT in Germany o PhD 1874 Paul Muller “discovered” DDT in 1938 1942: DDT was sent by Swiss to U.S. o secret army lab was set up in Orlando, Fl o tested DDT against lice (which spread typhus) o U.S. army 1 used DDT in North Africa & Italy Frank Mayo o Atlanta chemist during World War Two o DDT production was a military secret o Process was published in Germany o Where could he find the publication? Athens Video: o New technology right after WWII: pesticides, plastics, fertilizers o DDT saved millions of lives in WWII First war where enemy killed more than disease (spread by lice) Massive growth of chemical industry Silent Spring was dedicated to Albert Schweitzer : “Man has lost the capacity to foresee and forestall. He will end by destroying the Earth.” Entomologists: o Before 1950, were “figures of fun” o After 1950, worked for chemical companies o started to see “side effects” o evaluated “degrees of badness” o UGA & Velsicol made Goodbye Mrs. Ant o “without DDT, insects would inherit the Earth” Ethical issues for entomologists: o Should UGA entomologists work for chemical companies? May not get money if s/he gets “wrong” result o Can entomologists assess pesticide damage to the environment? Silent Spring by Rachel Carson o Bill of Rights should protect us o Powerful pesticide industry fought her o Government withheld information o Frequent cover-up of wildlife damage o Most insects controlled by other insects o “you can’t eradicate an insect with a chemical” o Dieldrin (pesticide more toxic than DDT) of fire ants in Georgia Everything had died: “no effect” o Toxic chemicals available in grocery stores Rachel Carson- lived during the Great Depression o 1932- Masters in Marine Biology at John’s Hopkins-age 25 o 1936- U.S. Bureau of Fisheries -age 29 asked to be a writer o 1962- Silent Spring published died of cancer Silent Spring o One of the most important books ever published o Impact due to Carson’s eloquence “Those who contemplate the beauty of the Earth find reserves of strength that will endure as long as life lasts,” –Rachel Carson 1964: Ruth Harrison wrote Animal Machines o foreword by Rachel Carson Silent Spring o Carson wrote with “emotionality” o Velsicol tried to stop publication o JFK & Udall became “aware” o Becomes best seller o Industry: “Silent Spring is full of errors” o Jukes: “No pesticide residues in food” Silent Spring sales soared o Within 1 year: pesticide bills introduced in 40 states o CBS TV interview o Opposition: Dr. Robert White-Stevens o What is “The Balance of Nature”? o U.S. Senate hearing “The modern scientist believes that man is steadily controlling nature.” – Robert White-Stevens “The balance of nature is built of a series of interrelationships between living things & between living things and their environment.” –Rachel Carson Victor Yannacone of the Environmental Defense Fund led fight against DDT use. o Hearings held in Wisconsin 1968-1969: If DDT is so bad, why doesn’t it make people sick? o Turning point: DDT is present in Human Breast Milk! DDT use was banned 1962: Silent Spring was published 1970: Environmental Protection Agency established 1972: DDT banned by EPA Silent Spring o Carson did not want to ban pesticides o Carson was a revolutionary o She made us aware of the environment DDT o Very cheap and very stable o Interferes with nervous system o Fat-soluble o Causes reduced calcium in bird eggs o Was banned in U.S. in 1972 o Production in U.S. continued for many years o Is still used in many parts of the world DDT Biomagnification o DDT is trapped in animal fat o As DDT travels up the Food Chain, the concentration increases Pesticides in U.S. o Farmers use 75% o Government and industry use 10% o Homeowners use 10% o Forestry uses 1% Pesticides: o Contaminate groundwater o Persist in deep soil because low oxygen and few bacteria o Most pesticides are untested for cancer o Cancer tests are for one pesticide, but most crops get several pesticides Pesticides and cancer o Farmers are at higher risk-especially migrant workers o Does long-term exposure cause cancer? o Most pesticides have not been tested for cancer o Synergistic (2 or more pesticides may act together to be worse than one pesticide) David Pimentel, Department of Entomology, Cornell University o How much does it cost to apply pesticides? o Each year $4 billion is spent in U.S. to apply pesticides o Increased yield from this expense= $16 billion Pimentel o Less than 0.1% of pesticides applied to crops reach target pest 1994: UGA student suffers from pesticide spraying in her dorm 1996: She works in Georgia legislature, and this leads to new state law: “state buildings must post notice when pesticides are sprayed” EPA & Pesticides o We must “trust” the Pesticide Industry o “Old chemicals” protected o Many old pesticides may cause cancer Migrant workers are often exposed to very high levels of pesticides Pesticide Treadmill o Insect becomes resistant to pesticide o Must apply greater amount of chemicals to kill pest insects o Then, apply more toxic pesticides Pesticides and Children o Pesticide levels are 5X too high o Developing bodies are more susceptible o Residue levels calculated for adults o Balance health vs. profit Income spent on food: o U.S spends less Victor Yannacone: “1 part per million is significant” Human sex hormones & pesticides “Every man in this room is half the man his grandfather was” o sperm count Some pesticides mimic human sex hormones! Human sex hormones and pesticides o 2010 Sperm count ½ 1950 o exposure to DDT in girls causes 5 fold increase in breast cancer Our Stolen Future Theo Colborn 1996 o Danger of environmental estrogens o Man-made chemicals (including pesticides) in the environment mimic estrogen hormones o In the body, estrogen hormones interact with a receptor in a lock and key fashion o Man-made chemicals fit into receptor site and act like estrogen hormones Block estrogen hormone action and affect metabolism Florida: Lake Apopka o Major DDT spill in 1980 o Decline in number of alligators o 75% alligator eggs are dead o 25% of male alligators have small penises o many male turtles are “intersex” Estrogens are added to shampoo and skin creams o Girls around the world are reaching puberty at an earlier age Is there a correlation? Breasts o A Natural-and-Unnatural History o Florence Williams 2012 DES=a synthetic estrogen o From 1940-1970, DES was given to 5 million pregnant women to reduce miscarriages o DES was given to girls who were “too tall”, had acne, and to stop flow of mother’s breast milk o DES given to chickens and cows to promote growth o 1971-women whose mother’s took DES are much more likely to develop vaginal cancer o DES effect takes place 20 years later! Thalidomide was given to pregnant women to combat morning sickness o In 1962, Thalidomide was shown to cause birth defects o Placenta does not protect fetus from chemicals o Thalidomide is now used to treat leprosy Captan is probably carcinogenic o Applied to Florida strawberries o Canada has set lower tolerance levels o Are U.S. tolerance levels safe? o Captan still provides economic benefits to growers Silent Spring o Chapter 17: The Other Road (Robert Frost) “road less traveled by”=use biological control, instead of chemical pesticides IPM=Integrated Pest Management o Know the pest o Judicious use of pesticides o Host plant resistance o Biological control Know the Pest o Life cycle of insect o How does the pest reproduce? o When is the pest a problem? o Which stage of the insect is the most susceptible? o Attack the pest when it is most vulnerable! Judicious use of pesticides o Apply pesticides when pest is present and vulnerable o Use of “scouts” or pheromone traps to monitor pest o Monitor environmental conditions o Use of Ultra Low Volume Sprayers Host plant resistance o Breeding programs o Introduction of resistance by crossing with “new” varieties Chemical Physical o Introduction of resistance by recombinant DNA technology “Designer genes” ex. Monsanto: B.t. Cotton Will resistance be a problem? Leaves of “Wild” Insect-Resistant Potato Plants from South America have 2 kinds of hairs o Sticky hairs trap aphids o Hairs make “alarm pheromone” that deters aphids o Goal: breed these traits into domestic potato plants Split-screen video o B.t. gene was put into soybean o The caterpillar on the leaf with B.t. keeps moving and does not feed For the last 50 years, seed companies did not bother to have insect resistance in their crop varieties o Because they would recommend a chemical pesticide Now they want Host Plant Resistance Most of our crop plants are not native to U.S. o Search for resistance in native country o Breed resistance traits into high-yield varieties Ethical issue: o Seed companies take genes from plants in third world countries o Produce insect-resistant plants o Should company share profits? Biological control o Sterilization o Beneficial insects o Bacteria that attacks insects Bacillus thuringiensis B.t. ) o Viruses that attack insects Sterilization o Pest insects: Rear in lab Sterilize Release Insects mate in field No progeny o Problem: Most insects are hard to rear in the lab Beneficial insects o Parasitoids o Parasitic wasps o Parasitic flies o Predators Preying mantids Dragonflies Paper wasps Spiders Parasitoid o Insect whose larvae consume their host Predator o An animal that kills and eats animals External parasitoid o Female wasp paralyzes caterpillar with venom Lays eggs on outside of caterpillar Larvae hatch and feed on caterpillar o Female wasp determines sex of her young Fertilized egg=female Unfertilized egg=male Internal parasitoid o Female adult wasp lays eggs inside of caterpillar Larvae hatch and eat caterpillar from the inside But don’t damage internal organs Larvae ooze out of host and spin cocoon Bacillus Thuringiensis B.t. o There are several varieties o Each variety is specific for one group of insect o Bacteria produce toxic protein, which kills insect o B.t. protein is not toxic to higher animals o Current use: gypsy moth in North Georgia B.t. o Must be eaten o Toxin destroys the insect’s stomach o B.t. is NOT slow acting o New strains are being sought Bacillus o B.t. attacks insects o Anthrax is also a Bacillus bacterium Viruses that attack insects: o Are very specific, only a few insect species are attacked by each type of virus o Have no effect on higher animals o Multiply in great quantities in host insect o Act too slowly o Pest insect lives for several days after eating virus UGA & American Cyanamid: o Mite toxin is insect specific o Insert gene for mite toxin into virus DNA o Pest insect dies very quickly o Virus still has narrow host range o No effect on humans or other animals o Also use toxins from scorpions and spiders Biological classification o Arrangement of living organisms into categories Taxonomy o Classifying organisms into categories Carolus Linnaeus o Swedish naturalist o 1753 o Linnaean binomial system o Genus Species Phylum: Arthropoda Class: Insecta Order: Diptera Family: Muscidae Genus: Musca Species: domestica Species o Organisms that closely resemble one another and can produce fertile offspring Scientific name=Genus species o Ex. Musca domestica o Common name: house fly 10 reasons why insects are so successful: o 1. Hard exoskeleton Positives: Provides protection Muscles attach to exoskeleton Limits water loss Negative: When insect grows, it must molt o 2. Jointed appendages On head=used for feeding On thorax=used for locomotion On abdomen=used for reproduction Allow for specialization o 3. Wings Escape from predators Find food Find a mate o 4. Small size Positives: Can hide/escape from predators Light enough to be blown by wind Negatives: Large surface to volume ratio Water evaporates quickly o 5. Metamorphosis Incomplete metamorphosis 13% of insect species Egg-Nymph-Adult Complete metamorphosis 87% of insect species Egg-Larva-Pupa-Adult Positive: Nymph/larva may occupy a different habitat than adult o 6. Escape from adverse conditions Migration Diapause: A period of arrested development In Fall, is triggered by short days Caterpillar increases weight 3000X Butterfly wings=great color diversity o Bright wings warn predators o May provide camouflage Random flight of butterfly protects it from predators o 7. Methods of reproduction Sexual Positive: o Provides genetic variation Parthenogenesis Reproduction without mating o Positive: No need to find a male o 8. Short generation time 2 advantages: increased genetic variation better utilization of limited food source o 9. Specialization in lifestyle Positive: Develop special skills Negative: If host decreases o 10. Solve the water problem Extract water from host sugar Limit water evaporation Cuticular lipids o Prevent dehydration o Sex recognition o Nestmate recognition o Host recognition Limit water excretion Nitrogen excretion Aquatic animals=ammonia Mammals=urea Most insects=uric acid Uric acid is: o Water insoluble o Non-toxic Insect walking o 6 legs are used as 2 alternate tripods Insect wings o Most adult insects have wings o Primitive insects: wings do not fold o Advanced insects: wings fold Easier to escape from predators Insect cuticle o Main component is Chitin o Chitin=aminosugar polymer Insect circulatory system o Is an “open system” o Hemolymph=insect blood Distributes nutrients and hormones Hormone o Chemical signal that is: Formed in specialized cells Travels in body fluids Interacts with target cells Pheromone o Chemical produced by an animal that affects another animal of the same species Insect pheromone o Sex: find mate o Alarm: warn others of danger (bees, wasps) o Aggregation: attract others to food (bark beetles) o Trail: follow leader to find food (ants) Gypsy moth: o Female releases sex pheromone o Male detects pheromone with large antennae Follows plume of pheromone upwind If wind changes, turns around to find pheromone Can find a female 5 miles away Use pheromone as biological control o Pine shoot moth: Identify sex pheromone Produce artificial pheromone Saturate forest o Males can’t find females Insect chemical ecology o The relationship between a chemical, an insect, and the insect’s environment Thomas Eisner o Department of Entomology o Cornell University A black beetle is attacked by ants o Bombardier beetle is not attacked Sprays toxic chemical from abdomen Mouse kills beetle by forcing end of its abdomen into the soil Bombardier beetle o Chemical reaction takes place in the abdomen o Reaction produces: Quinones + Heat + Oxygen + Noise o Toxic spray can be aimed Bolas spider o Spider spins a silk strand with sticky ball on end o Throws ball at prey and then reels it in o Catches moth of only 1 species o All moths are male o Spider emits smell like the female moth sex pheromone o Male moth is attracted to spider and caught Use GC/MS to identify insect chemicals o Gas chromatography/mass spectrometry Many insects produce (or sequester) toxic chemicals for defense Aposematic : bright coloration warns potential predators of the chemical defense Monarch Butterfly o Larvae feed on milkweed o Sequester toxic alkaloids o Larvae and adults are aposematic o Protected from predators Video Caterpillar eats toxic plant o Caterpillar and adult moth are aposematic o Spider rejects toxic moth Accepts “lab moth” with no toxin o Birds learn to avoid aposematic moth o Spiders do not learn to avoid aposematic moth o Male moth gives toxin to female moth o Female moth selects most toxic male moth Eisner: “We should form a global alliance to protect the environment.” Ecology: the relationship between organisms and their environment Insect ecology : the relationship between insects and their environment Grizzly Bear Habitat o Montana o Bears and people compete for space have become a danger need to find “old” food sources now feed on a tiny moth Mutualism: relationship between 2 species that benefits both parties Symbiosis: intimate relationship between 2 species, usually involving coevolution Coevolution: occurrence of genetically determined traits in 2 species selected by the mutual interactions controlled by these traits Dan Janzen in Costa Rica: o Ants live in Acacia tree Mutualistic relationship Ants protect trees from leaf-eating insects Tree provides: Ants live in the thorns Eat sugar from glands at leaf base Eat Beltian bodies (rich in fat) from leaf tip o Other interactions on the ant-Acacia: Beetle protected with thick cuticle 2 wasp species protect each other (mutualism) bird nest; ants attack for awhile in trees with no wasps : o monkey attacks bird nests spreads plant seeds Environmental concerns: o Threat to Monarch Butterflies Larvae fed milkweed with pollen from B.t.-corn die (lab study) Pollen may blow from B.t.-corn to nearby plants and cause death of monarch butterflies Field studies show pollen does not go far o Mistletoe Butterfly: Lay eggs on mistletoe Larvae eat leaves Mistletoe is a parasite of eucalyptus Mistletoe birds feed on mistletoe berries Birds defecate seeds onto eucalyptus branch Mistletoe seeds germinate on eucalyptus Biodiversity: o Variation in living organisms o Humans have disproportionate impact on all others species o Species loss is greater than ever before o Deforestation=27 million acres/year o Research should use biodiversity to increase food production and yield new medicines E.O Wilson o Harvard University o 1992 o The Diversity of Life Named species of plants and animals: 1.82 million Bird species in New Guinea o Museum collection says 125 o Natives say 124 o Bird species are distinct Ant species in New Guinea o Museum collection says 95 o Natives say 1 o An ant is an ant There is greater biodiversity in the tropics o From 1 tree in Peru: 43 species of ants o Equal to the number of all ant species in the United Kingdom Forest Canopy o Many of the unknown species of insects are in the forest canopy o Get into forest canopy with ropes, cranes, and walkways How many insect species are there? o T erry Erwin Smithsonian Institute Washington D.C. Estimate arthropod tropical biodiversity Look at 1 tree species in Panama Fog tree with pesticide Find 1,200beetle species 163 are host-specific there are 50,000 tropical trees there are 8,000,000 beetles beetles=40% of arthropods o total=20,000,000 Ground-dwelling=10,000,000 Total tropical arthropods=30,000,000 There are between 10,000,000 and 30,000,000 insect species on Earth E.O. Wilson o Theory of Island Biogeography Deforestation creates “islands” How many species can exist in such “islands”? How big should a protected National Park be? Loss of biodiversity due to habitat destruction Species loss: o Dinosaur age=1 species every 1000 years o Today=1 species every day Food plants have lost biodiversity! o 1970 corn blight in U.S. o $5 billion damage Order: Isoptera o Iso=equal o Ptera=wings o Common name=termites o Species=2,230 Termites: o incomplete metamorphosis o Highly social o Caste system (social class) o Symbiosis with protozoa or fungi to degrade the cellulose in wood o Reproductives have wings o beneficial: recycle nutrients o Pest: destroy wood structures o Social insects have guests o Are related to cockroaches o Architecture is free form Adjusted to the environment o Use saliva as cement Termite castes: o Soldiers o Workers o King o Queen Termite mound: o Royal cell contains queen, king, and workers o Termites feed each other and exchange chemical messages o Eggs are taken to nursery where nymphs are reared o Termites use fungus garden to break down cellulose o Keep mound cool by water evaporation T ermites have the largest colonies of all social insects Traits of social insects: o Reproductive division of labor o Cooperative care of young o Overlap in generations Termites: o Build and tend fungus gardens o Adults: only reproductives have wings Fly off, meet a mate, and break off wings Female and male start a new colony o Have many kinds of predators Termites follow trail pheromones: o Is present in ink of some pens Termites in Kenya: o Men own the termite mounds o Kenyans collect, process, and eat winged adults o Termites are 40% fat and 40% protein Termes=the end Order: Ephemeroptera o Ephemera=short-lived o Ptera=wings o Common name=mayflies o Species=2,000 Mayflies o Incomplete metamorphosis o Eggs laid in water o Nymphs: breathe with gills feed on plants live 1-3 years o Adults: Emerge at same time do not feed have 2 pairs of wings have 2-3 tails mate and die in 1-2 days Taxonomists: o Lumpers : have few orders o Splitters: have more orders o There are approximately 26 insect orders Keying insects to order and family o Use adult insects o Use couplets or triplets Mayflies: o Have a good sense of timing o Nymphs live 1-3 years o Adults live 1-2 days Fisherpeople: o Use lures that mimic insects present in the stream Nymph has gills and tails Emerging mayfly adult is vulnerable Match the mayfly “hatch” o Observe behavior of fish Use adequate insects to monitor water quality o If water is clean, there are many kinds of insects Insects are sensitive to oxygen levels and water acidity Insects that walk on water o Springtails have tail under body o Water measurer has piercing/sucking mouthparts Order: Odonata o Odous=tooth o Common name: dragonflies, damselflies o Species: 5,000 Dragonflies & Damselflies o Incomplete metamorphosis o Biting mouthparts o 2 pairs of wings o VERY large eyes o VERY small antennae o Long abdomen o Nymphs are aquatic o Nymphs and adults are predators o Considered beneficial o Front and back wings beat independently Damselfly vs. dragonfly o Damselflies: are smaller than dragonflies hold wings straight back at rest dragonflies hold wings out to side lay eggs in plant stems under water dragonflies lay eggs on water surface Note: o Adults regulate their temperature o Nymphs are predators o “nymph” stage lasts for 1-3 years o nymph to adult stage is dangerous o must first pump hemolymph into its wings Damselflies & Dragonflies: o Use leg hairs to catch prey o Excellent fliers o Muscles are attached to wings (like birds and bats) Insect behavior: reaction of insects to specific conditions Note: o Males are territorial o Mate in “wheel position” o Male first removes rival sperm from female o Male and female are in “tandem” during egg laying This keeps other males from mating with female Order: Blattodea o Blatta=cockroach o Common name: cockroaches o Species: 3,500 Cockroaches o Incomplete metamorphosis o Chewing mouthparts o 2 pairs of wings o natural omnivores o flattened bodies o eggs laid in case=ootheca o domestic pests omnivore : eats both plants and animal material cockroaches can be a nuisance in the kitchen cockroaches are adapted to living with humans only 20 cockroach species are pests peripheral vision antennae detect food and water o keep antennae clean tail hairs are sensitive to movement cockroach Defense Against Pest Control “Bait” o smell bait at a distance o touch bait with antennae o touch bait with hairs on mouthparts o chew and taste bait o cockroaches spread diseases (bacteria) mechanically! o And they can cause allergies Termites evolved from cockroaches: o Cockroach fossils are around 300 million years old Some eat wood o Like termites, these cockroaches have protozoans to digest cellulose o Protozoans are passed on to baby cockroaches via feces o Female cockroach “cares for young” by carrying ootheca Cockroach reproduction o Male strokes female antennae to identify her o Male offers a food gift to her o They mate end to end o Females mate once and store sperm o She can have 7 broods o Ootheca has 40 eggs o Nymphs burst ootheca by gulping air Order: Orthroptera o Orthos=straight o Ptera=wings o Common name: grasshoppers, crickets, locusts o 20,000 species Grasshoppers/Crickets o Incomplete metamorphosis o Chewing mouthparts o Front wings are narrow o Back wings are fan-like o Strong hind legs o Males produce sound o Sound receptors on leg/abdomen o Oviposit eggs is soil or a plant o Plant eaters o Major agricultural pests Stridulation: production of sound to attract a mate Cricket songs: o Each species is different o More chirps/second=higher temperature o Establish territory o Call a female o Warn others of predators How is sound produced? o Crickets and some grasshoppers: Rub a wing against a wing o Grasshoppers and locusts: Rub a leg against a wing o Wings and legs have bumps and ridges= “file & scraper” o Wings can serve as an amplifier Crickets & Grasshoppers: o “call” to find a mate o mate at night to reduce danger from predators o some predators and parasites are attracted to “call” o it is safer to be a strong “silent” male Cricket uses: o Court case to lower rent o China: raise crickets for fights o Sell for fish bait o A cricket genus=Gryllus Locusts: o #1 agricultural insect pest in the world o 2 phases: solitary; gregarious o stimulation of hairs on back legs of solitary locusts causes swarming: solitary locusts-----> gregarious locusts o swarm may cover 500 square miles and have 50 billion insects! o “nymphs” stay in soil several years during a drought o “blew/flew” to the Americas from Africa Locust swarms in Africa: o Eat: 2,000 tons/day o Travel: 65 miles/day o Oviposit in soil o 1 female-500 nymphs Locusts have plagued us since biblical times o Exodus Chapter 10: “I will bring locusts into your country…and they shall fill your houses…” Order: Hemiptera o Hemi=half o Ptera=wings o Common names: bugs, aphids, scales, cicadas o Species: 68,000 Hemiptera o Incomplete metamorphosis o Piercing & sucking mouthparts o Pest of crops o Transmit disease “True” bugs o mouthparts (“break”) swing forward o many species are predators o base of forewing is hardened o back of forewing is membranous o many have stink glands Assassin Bug o Piercing/sucking mouthparts Hemiptera o Bed bugs feed at night Inject an anesthetic Suck human blood Vector: a means of biological transfer Human diseases o Know: Common name of disease Scientific name of disease agent Disease agent=what type of organism (protozoan, bacterium, or virus) Arthropod vector Chaga’s disease o Vector: assassin bug (kissing bug) o Disease: Trypanasoma cruzi (protozoan) o One million people die per year o Primarily in South America o Attacks the heart o Hard to diagnose; no cure o Reservoir hosts=opossums and armadillos Spread of Chaga’s disease: o Kissing bug feeds on victim at night Defecates on victim’s face o Victim rubs feces and Trypanasoma into wound Xenodiagnosis of Chaga’s Disease: o Laboratory kissing bug feeds on victim o Kissing bug tested for Trypanasoma in feces (10 days later) o Do you make the kissing bug a carrier of the disease? Xenodiagnosis : use of a live vector to diagnose a disease Aphids o Mouthparts (“break”) swing down o Plant feeders o Membranous wings o Major agricultural pests Aphids: o Have many predators o Give birth to nymphs o Plant defense=sticky hairs o Are usually wingless o Overpopulation results in winged aphids Ants tend to aphids as if farming Honeydew: a sweet, sticky substance excreted by aphids Honeydew production by aphids: o Allows water excretion! o Attracts ants o Can cause fungal growth o Honeydew=manna Aphids: o Piercing/sucking mouthparts o Tended by ants for honeydew Hemiptera diversity: o Bugs o Aphids o Scales o Cicadas o spittlebugs Order: Coleoptera o Coleo=sheath o Ptera=wings o Common name: beetles, weevils o Species=300,000 Coleoptera o Complete metamorphosis o Chewing mouthparts o Forewings hardened o Hind wings membranous o Thickened exoskeleton o Pests of crops and trees o Largest insect order! Metamorphosis : change in the structure and habits of an animal Complete metamorphosis o Egg o Larva o Pupa o Adult Complete metamorphosis: o 4 stages often very different in: appearance habitat host predators & parasitoids ladybugs: o hop plants in UK were burned to kill aphids o lift up front wings and fly with hind wings o are beneficial; eat aphids o adult ladybugs overwinter in massive clusters o are collected and sold for biological control Fireflies: o Each species has a unique flash pattern o Male flashes to attract female o Female flashes in response o Male and female have different flash patterns o Some females mimic flash patterns of females of other species and prey on males Firefly larvae are aposematic o They glow to deter predators Fireflies flash in unison only in India & Tennessee Fireflies o Produce light with Luciferin, a pigment which yields light when combined with oxygen o 98% of energy is released as light DUNG is a valuable food source Elephant dung beetles: o Many insects are attracted to dung o Have specialized mouthparts o Roll dung into balls o Civet cats feed on dung beetle Produce civetone in anal gland Is used in perfumes Australia o Cows were imported o Insect couldn’t cope with dung o Grassland was lost o Solution: import dung beetles Ancient Egypt: o The scarab=a stone beetle Was the symbol of the soul Was also called the sun god Ra o Beetle metamorphosis may have inspired pyramid construction Spanish fly=blister beetle o Produces a toxin: cantharidin Hippocrates used as medicine Marquis De Sade used as aphrodisiac Causes burning sensation in groin Destroys mucous linings in the body! Acorn Weevil o Female has a long snout (mouthparts) o Drills hole in acorn with snout o Then, oviposits in this hole o Lays one egg per acorn Whirligig beetle o Is a scavenger o Has divided eyes so it can see above and below water o Spins in circles to create waves that bounce back when they hit food item o Carries air bubble to breathe underwater Order: Lepidoptera o Lepido=scale o Ptera=wings o Common name: butterflies & moths o Species=200,000 Lepidoptera o Complete metamorphosis o Siphoning mouthparts o Wings have scales o Scales=modified hairs o Larvae feed on plants o Larvae spin silk o Greatest color variation o Major agricultural pest Butterfly o Greek=psyche o French=papillon Entomology: study of insects Etymology: study of words Morpho butterfly o Morpho=beautiful or well-made o Upper wings are iridescent blue o Lower wings are plain brown Lepidoptera larvae o Are leaf eating machines o Must molt 4-5 times o Have soft cuticle o Need defense: Camouflage Warning coloration Toxic spines Lepidoptera adults o Feed to get flight fuel o Mate abdomen to abdomen o Female lays eggs in host plant Butterflies=20,000 species Moths=180,000 species Dan Janzen: o Identify all the moths of Costa Rica Rear larvae to adults then identify Use light screen at night to collect adults o Moth scales can cause allergies How big should a biodiversity park be? Florida Queen butterfly o Looks similar to viceroy o Finds mate with sex pheromone o Male and female do courtship dance o Male uses “hair pencils” to dust female with pheromone Monarchs: o Larvae feed on milkweed o Sequester toxic alkaloids (cardenolides) o Predators leave larvae and adults alone o Fall: 4 generation adults Migrate 2,500 miles to Mexico o Winter: dormant in Mexican forests o Spring: mate and return to U.S. Mexican holiday o Return of the monarch butterflies o Represents the return of the souls of people who died during the year Insect plant interactions o Coevolutionary arms race Plant produces toxin Insect adapts to toxin Plant makes more powerful toxin Plant defense against herbivores o Silicon oxide in leaves Like eating glass o Proteinase inhibitors Animal can’t digest food o Secondary plant products Toxic compounds Plant surface has hairs=trichomes o May produce toxins o May be sticky o May be spines or hooks When plant is wounded it wants to: o Limit water loss o Prevent fungal/bacterial infection o Deter herbivory When a plant is wounded it may: o Wound-heal to give a “scab” o Produce toxic chemicals o Exude sap or gum o Form a gall (with insect inside) Jurassic Park o Fossilized plant resin=amber-gem o DNA found in fossil insects o Sequence fossil DNA o Determine relatedness of insect species o Recover dinosaur blood (DNA) from fossil mosquito Carnivorous plants: o Habitat low in nutrients o Digest protein of prey o Have modified structure to catch insects Carnivorous plants o Sundews o Venus fly trap o Bladderworts o Pitcher Plants Sundews o Bright colors attract insects o Leaf tentacles have sticky glue o Electrical signal causes leaf to curl o Leaf uses enzymes to digest prey Venus fly trap o Has trigger hairs inside leaf Touching hairs causes electrical signals o 2 signals cause rapid growth of outer leaf o leaf closes on insect; Venus fly trap digests it o only found in wetlands of North Carolina and South Carolina Bladderworts o Are aquatic o Have a bladder with a trap door o When prth item hits trigger hair, it is sucked into bladder in 1/1000 of a second! Pitcher plants o Flower-like: nectar and color attract insects o Inside: downward pointing hairs and loose wax o Insects fall into “pool” and are digested Order: Diptera o Di=two o Ptera=wings o Common name: Flies & mosquitoes o Species: 90,000 Diptera o Complete metamorphosis o Mouthparts: piercing/sucking or sponging o 1 pair of membranous wings o no hind wings o halteres=stabilizers (replace hind wings) o primitive larvae=maggots o many larvae are aquatic o most harmful order: many members cause disease Flies o Flies are best insect fliers o Hoverflies: 175 wing beats/second o Halteres give stability House Fly: o Regurgitates on food Enzymes soften food Then, uses sponging mouthparts o Transmits disease mechanically: Picks up disease somewhere and carries disease to another location o Can “see” movement very well o Uses leg hairs to taste o Has SPONGING MOUTHPARTS o Oily hairs on feet: walk on ceiling Fly farms o Maggots are used to eliminate animal farm waste Medical treatment o People with poor circulation o Leg (or arm) wounds heal slowly Add fly maggots to wound Maggots eat dead flesh Prevents amputation African Sleeping Sickness o Vector: tsetse fly o Disease: protozoans Genus: trypanosoma o Drug treatment is effective o 165,000 deaths per year Sleeping sickness kills people and cows o Wild animals=reservoir host o Africans can’t raise cattle o People of Africa need more protein o Tsetse fly=”Guardian of Africa” Because native habitat has been saved Tsetse Fly Female: o Does not lay eggs o Has 1 egg that hatches inside female fly o Larva develops inside female fly o Mature larva is born Burrows into soil and pupates Adult emerges from soil o Produces only 8 larvae! Mosquito life cycle o Eggs laid in or near water o Aquatic larvae o Aquatic pupae o Adults live 1-3 weeks o Female mates in male swarm o Male feeds on flowers o Female needs “blood meal” Mosquito larvae have a siphon tube for breathing Mosquitos have piercing/sucking mouthparts! Mosquitos: o Female attracted to host carbon dioxide o Sound of female wings attracts male Mosquitos-piercing/sucking mouthparts have: o Protective sheath o Tube to suck blood o Knife-like mouthparts o Saliva injector (stops blood clotting) 1/6 of humans have an insect-vectored disease o malaria has killed more people than any other disease o 1897: Ronald Ross showed that mosquitos vector malaria o 1900:Walter Reed showed that mosquitos vector yellow fever Yellow Fever o Vector: mosquito Genus: Aedes o Disease: virus o Reservoir host: monkeys o Worst in South America & Africa o No effective treatment Dengue Fever o Vector: mosquito Genus: Aedes o Disease: virus o No effective treatment o South America, Africa, & Caribbean Zika Fever o Vector: mosquito Genus: Aedes o Disease: virus o No effective treatment o South America, Africa, & Caribbean o Special concern: pregnant women o Zika may cause microcephaly Malaria o Vector: mosquito Genus: Anopheles o Disease: protozoan Genus: plasmodium o Drug treatment is effective o South America, Africa, & Asia Malaria life cycle o Mosquito feeds on infected host o Plasmodium mates in mosquito’s stomach Moves to salivary glands o Mosquito feeds on new host o Plasmodium moves to host liver Attacks red blood cells Red blood cells rupture o Cycle repeats in host: 24, 48, 96 hours Mated female mosquito: o Eggs do not develop without a blood meal o Head produces hormones needed for egg production Natural Selection in Africa: o A mutation changed structure of hemoglobin o This change provided resistance to malaria o People with 1 copy of the gene survive malaria o People with 2 copies of the gene have Sickle Cell Anemia Order: Siphonaptera o Siphon=tube o Aptera=wingless o Common name: fleas o Species=1,800 Siphonaptera o Complete metamorphosis o Piercing/sucking mouthparts o No wings o Adults of both sexes are blood-sucking parasites o Good jumpers and runners o Narrow body o Many are disease vectors Fleas: o Female needs blood for eggs o Female eats 15 times her weight/day o Female lays 2000 eggs o Eggs hatch in 1-10 days o Larvae feed on adult feces o Larva spins a sticky cocoon o Cocoon is well camouflaged o Life cycle is 12-174 days o Environment (temperature and humidity) is very important Fleas are attracted to: o Heat o Carbon dioxide o Light o Movement Fleas: o Can jump 200 times their length o Resilin: a protein in the back legs of fleas that works like a rubber band Miriam Rothschild is a world flea expert o She showed that female flea reacts to sex hormones of a pregnant female host Female flea adjusts her reproductive cycle to match that of her host o Lays her eggs on babies of host Bubonic Plague o Vector: fleas o Disease: bacteria Yersinia pestis o Antibiotic treatment is effective o Found in Russia, Middle East, and Western U.S. o Major outbreak in India Bubonic plague: o Reservoir=rodents o Bacteria enter flea with blood meal o Bacteria multiply in flea gut o Bacteria break entry to gut o Flea seeks new host o Flea feeds on new host o Regurgitates blood with bacteria o Host is infected Elephantiasis o Vector: mosquitoes o Disease organism: roundworms o Causes swollen appendages o 300 million people in Southeast Asia have Elephantiasis River Blindness o Vector: black flies o Disease: roundworms o West Africa o 20 million people infected Possible use of insects in war o Modify plague bacteria o Destroy crops o War on drugs Mimicry : Resemblance of an organism to some other organism/object Natural Selection: change in the frequency of genetic traits in a population through differential survival of individuals bearing those traits Natural selection: o Blue jay (a predator) eats moths o 50 years ago most moths were pale o pale moths were hard to see on trees o pollution darkened trees o today most moths are dark o dark moths are now harder to catch Batesian mimicry: resemblance of an edible species (mimic) to an unpalatable species (model) to deceive predators Batesian mimicry: o Viceroy looks like monarch butterfly o Monarch larva eats toxic milkweed o Viceroy larva eats non-toxic willow o Monarch adult is toxic=model o Viceroy adult is non-toxic=mimic o Blue jay “learns” to avoid mimic Mullerian mimicry: mutual resemblance of 2 or more unpalatable species to enhance predator avoidance Crypsis: resemblance of an organism to its background Dead Leaf Butterfly o Outer wings look like leaf o Inner wings have bright color Wing edge of moth/butterfly may mimic caterpillar or snake Nemoria arizonaria o Spring Caterpillar eats oak flowers: mimics flowers o Summer Caterpillar eats oak leaves: mimics twigs o Passion vine & butterfly interaction: o Passion vine leaves have toxins to deter insects Some butterfly species can eat only 1 passion vine species Passion vine leaves mimic each other to confuse butterfly o Female butterfly lays one egg per leaf, because larvae are cannibals! Passion vine makes “mimic eggs” on leaf Butterfly avoids passion vine leaves with “mimic eggs” Mantids can “hear” the sonar of bats o Mantids dive to avoid the bats Importance of “behavior” in mimicry: o Caterpillars avoid birds Birds see leaf damage and find caterpillars Cryptic caterpillars look like leaf or twig Caterpillar eats leaf symmetrically= “no damage” Hides behind leaf while eating Eats part of leaf; then clips leaf= “no damage” Order: Mantodea o Mantis=prophet o Common name: Mantis or mantid o Species: 1,800 Mantids o Incomplete metamorphosis o Chewing mouthparts o 0.5-6 in. long o raptorial forelegs o carnivorous o long thorax o eggs laid in ootheca o cryptic coloration Mantis: o Sways back and forth prior to attack o Has spines on front legs to hold prey o Has elaborate chewing mouthparts o WHEN THEY CATCH IT THEY DON’T LET GO! Why do female mantids eat their mates? o Theories: It releases male “inhibitions” and his sperm He provides mated female with nutrients But male is smaller-hard to eat him while mating Preying mantis o Eggs are laid in an egg case=ootheca Order: Phasmida o Phasma=apparition o Common name: walking sticks o Species: 2,500 Walking sticks o Incomplete metamorphosis o Chewing mouthparts o Long and slender body o Cryptic coloration o Feed on plants o Feign death when threatened o Autotomy: loss of a leg to escape Mantis: o Is a generalist predator o Uses antennae to recognize prey o Exerts selective pressure: prey with best mimicry survive Ethnoentomology : cultural importance of insects African Desert o Dig toxic beetle pupae from soil o Squish insects onto arrows Darrel Posey o P.h.D.-UGA 1979 o Ethnoentomology of the Kayapo of Central Brazil Kayapo o Agricultural-but few insect pests o Main pest=mosquito (body paint) o Eat: ants, bee larvae, wasp larvae Kayapo use of insects o Place ant colony near crop o Cultivate ant plants o Wasp colony in banana tree Kayapo o Ceremony to acquire power of wasps o Young men hit large wasp nest o Wasp nest=the Universe Vincent Holt o Why Not Eat Insects? 1885 Insects are nutritious o Protein o Fat o Vitamins (A and D) Australian Aborigines eat: o Beetle larvae: Witchetty Grubs (taste like chicken) New Guinea o Sago Palm provides: Starch=80% calories Larvae of Capricorn beetle=protein snack Insects are rich in protein! o Botswana-charcoal grilled caterpillars o Thailand-steamed bamboo worms Waterbugs Steamed hornet grubs Scott O’Grady o Shot down over Bosnia o Survived by eating bugs 1995 o Chinese female runners broke many track records Were they using illegal drugs? No-they ate a caterpillar infected with a fungus South American Indians eat: o Tarantulas: Capture tarantulas-avoid venom and toxic hairs Barbecue tarantulas-taste like shrimp Insects in the Arts o Butterflies are favorable subject Bubonic Plague o Ring around the rosies o A pocket full of posies o Ashes ashes o We all fall down Ogden Nash: Fleas o Adam had ‘em Poetry: Robert Frost o Fireflies in the Garden o Design (Spider & Moth) o Departmental (Ants) o The Road Not Taken (Silent Spring) Insects in language: o Busy as a bee o Grubby o Roach o Social butterfly o Waspish Insects in music o “Flight of the Bumble Bee” Rimsky-Karsakov o Mariah Carey- ‘Butterfly” Maria Merian o Combined art and entomology o Born in Germany o Went to South America at age 52 o Painted: larvae, pupae, and adult insects with hostplant Humor o Gary Larson Ento 2010 at Washington State University Far Side o Insects appear in cartoons more often in winter Insects in movies o Friendly “insects” humanized o People use no common sense o Frequent biological errors: very large insects can’t breathe Greatest insect movie: o THEM (1954) Giant ants mutated by H-bomb invade Los Angeles sewers Forensic entomology : study of insects from a legal aspect Insects as forensic indicators: o Estimate postmortem interval o Assess death scene o Corpse transport/relocation o Injury prior to death o Drug testing Estimate postmortem interval o Based on Blow Fly development o Most accurate in the first 30 days o Several Blow Fly species involved Blow Flies are the first to arrive at a corpse o Eggs are laid o Larvae develop o Development is temperature dependent o Succession of insects is predictable Basic assumptions in homicide investigation o Murder took place at night o Flies oviposit as soon as they find a body o Predictable succession o Weather station records valid o Air temperature determines fly development Forensic entomologist: o Recovers insects from the body o Identifies insects Maggot mass : large group of blow fly larvae in carrion o Maintain high temperature Decomposition studies o Test animal is sacrificed o Environmental conditions recorded o Succession of insects monitored Variations: o Body buried o Body in water o Body burned o Body in building Bodo University of Tennessee o Use human bodies Corpse relocation: o Few insects in soil beneath body o Insects from body are “foreign” Forensic entomology o Other aspects: Drug analysis of corpse Insects in food Poaching Case study: Oregon o Rifle fired at party o Neighbor killed o Body found 1 month later o Insect evidence set time of death Case study: o Young child brought to hospital o Suffered from abuse and neglect o Difficult to prosecute parents o Anal and genital areas had fly maggots o Larval age=5 days o Diapers had not been changed for 5 days o Similar example with elderly patients Case Study: Chicago o Woman raped by man in ski mask o Suspect had a mask in apartment o Suspect: “mask had not been worn” o Burrs in mask (and at crime scene) o Small caterpillars in burrs o Life cycle of moth: eggs are laid in summer o Mask had been outside in last 6 months! Ticks & mites o Class: Arachnida o Subclass: Acari o Species=30,000 Ticks and mites o 2 main body parts: cephalothorax & abdomen -no division between o usually 8 legs o egg-larva-nymph-adult o ticks parasitize: mammals, birds, reptiles o mites are: free living, plant/animal parasites Lyme Disease o Described first in Connecticut o Vector: deer tick o Disease agent is a bacterium: Borrelia o 15,000 cases per year in U.S. o most prevalent in northeast Lyme disease: o Ticks feed on infected mice o Bacteria multiply in tick vector o Ticks feed on man o Circular rash o Flu-like illness o Later: arthritis, heart, and nerve problems o Treatment: antibiotics Deer tick o Much smaller than dog tick o Nymph is the usual vector (1/3 infected) o Life cycle: Year 1: larvae hatch, feed, and molt Year 2: nymphs feed; adults emerge and feed o Birds disperse ticks Lyme disease: o Cause is unknown o May attack nervous system, heart, or joints o May cause an immune response to self o Patient response is very variable Lyme disease prevention o Protective clothing in woods o Check your body for ticks o Save ticks that you remove Tick removal: o Use fine-pointed tweezers o Grasp tick where it enters skin o Pull tick out slowly and firmly o Save the tick Rocky Mountain Spotted Fever o Vector: dog tick o Disease agent is a bacterium: Rickettsia o 800 cases per year in U.S. o most prevalent in the west Scorpions o Class: Arachnida o Subclass: Scorpiones o Species: 1,200 Scorpions: o 2 large pincers o tail with venom o predators o North African and Middle Eastern species can kill a human o Can survive extreme temperatures o Are blind; use feelers on legs to find prey o Male deposits sperm on stalk-then pulls female over stalk o Female bears live young and cares for them Spiders o Class: Arachnida o Subclass: Araneae o Species=30,000 Spiders: o Cephalothorax jointed to abdomen by pedicel o 8 legs o most produce silk o most produce venom o males deliver sperm with palps o very few cause harm to humans Spider diversity o Sun spider o Trapdoor spider o Whirling spider o Net-casting spider o Bolas spider Ball with mucous Moth sex pheromone o Mexican tarantula o Bird eating spider o Purse-web spider Camouflaged web Tarantulas o Covered with hairs o Can throw hairs at predators o Hairs are barbed and toxic Large-jawed spider: o Male produces sperm in abdomen and transfers it to a special web & then to the palps on his cephalothorax Jumping spider: o Male attracts female with mating dance where he puts her in “a trance” with front leg movements Net-casting spider: o Male “talks” to female by strumming on web o Male uses palps to deliver sperm to female o Female mates once and stores sperm o Male may mate many times St. Andrew’s Cross Spider: o Female is much larger than male o Male “plucks” on web to identify himself o He risks death in order to mate Orb weaver: o Stabilimentum: zig zag cross strands in web Warns birds so they won’t fly into web Some birds may use stabilimentum to find silk for their nest Most spiders are beneficial o Approximately 30 species (0.1%) can harm humans Spider venom contains: o Toxins that affect the nervous system o Enzymes that degrade tissue Black Widow spider: o Red hourglass on abdomen o Bites and injects venom Circulates in blood Is a neurotoxin Causes muscles to cramp; intense pain Black widow spider bite o Intense pain; peaks at 30 minutes o Nausea and profuse sweating o Slurred speech; body may go rigid o M.D. may diagnose appendicitis o Venom is 30 times more toxic than rattlesnake Brown recluse o “violin” on cephalothorax o venom causes skin necrosis First silk production: China 2640 B.C. o Si-Ling-Chi was: Goddess of the silkworms Secrets of silk production o Went first from China to Japan o Marco Polo brought back to Euro
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