1. 1. IntroductionIntroduction toto Agricultural EntomologyAgricultural Entomology Eric StormerEric Stormer Virginia Cooperative ExtensionVirginia Cooperative Extension
2. 2. Key TermsKey Terms EntomologyEntomology Siphoning insectsSiphoning insects ExoskeletonExoskeleton metamorphosismetamorphosis Larval stageLarval stage Pupal stagePupal stage Phytophagous insectsPhytophagous insects ParasitismParasitism DDTDDT Integrated PestIntegrated Pest ManagementManagement PheromonesPheromones
3. 3. What is Entomology?What is Entomology? EntomologyEntomology is theis the study of insects.study of insects. AnAn EntomologistEntomologist is ais a scientist who studiesscientist who studies insects.insects.
4. 4. Insect FactsInsect Facts More than 750,000 species have beenMore than 750,000 species have been identified.identified. Approximately two million species haveApproximately two million species have not been described or identified.not been described or identified. About 10,000 species are harmful toAbout 10,000 species are harmful to humans.humans. About 500 are considered major pests inAbout 500 are considered major pests in the USA.the USA.
5. 5. Insects Impact On HumansInsects Impact On Humans Have hindered workHave hindered work (Malaria, Panama(Malaria, Panama Canal).Canal).
6. 6. Insects Impact on HumansInsects Impact on Humans Have caused wide spread epidemics - BubonicHave caused wide spread epidemics - Bubonic Plague, 14th century Europe.Plague, 14th century Europe.
7. 7. Insects Impacts on HumansInsects Impacts on Humans Swarms (plagues) devastated crops, causedSwarms (plagues) devastated crops, caused widespread famine.widespread famine.
8. 8. Insects Impact on HumansInsects Impact on Humans
9. 9. Insects Impact on HumansInsects Impact on Humans Encourage diversification of crops (cotton, bollEncourage diversification of crops (cotton, boll weevils, peanuts).weevils, peanuts).
10. 10. Impact of InsectsImpact of Insects Contributed toContributed to the discovery ofthe discovery of America - tradeAmerica - trade routes to the Eastroutes to the East for silk.for silk.
11. 11. Insects Impact, ContdInsects Impact, Contd Invade our homes.Invade our homes. Spoil our food.Spoil our food. Destroy ourDestroy our belongings.belongings. Cause us discomfort.Cause us discomfort. Pollinate flowers ofPollinate flowers of our crops, that we useour crops, that we use for food and fiber.for food and fiber.
12. 12. Scientific Classification of InsectsScientific Classification of Insects Kingdom:Kingdom: AnimaliaAnimalia Phylum:Phylum: ArthropodaArthropoda Class:Class: InsectaInsecta Order:Order: 30+ exist30+ exist Binomial:Binomial: Genus, speciesGenus, species Example:Example: Apis melliferaApis mellifera (Honeybee)(Honeybee)
13. 13. Six Orders that damage plantsSix Orders that damage plants Orthoptera Orthoptera grasshoppers, locusts.grasshoppers, locusts. Hemiptera Hemiptera bugs.bugs. Lepidoptera Lepidoptera moths and butterflies.moths and butterflies. Homoptera Homoptera includes aphids.includes aphids. Thysanoptera Thysanoptera includes thrips.includes thrips. Coleoptera Coleoptera largest of alllargest of all orders,orders, includes beetles.includes beetles.
14. 14. Insect groupings by methods ofInsect groupings by methods of feedingfeeding Chewing insects use mandibles to tear offChewing insects use mandibles to tear off and grind up food (grasshoppers, beetles).and grind up food (grasshoppers, beetles). Chewing-lapping mouths used to lap upChewing-lapping mouths used to lap up liquid (bumblebees, honeybees).liquid (bumblebees, honeybees). Rasping-sucking mounts scrape off cellsRasping-sucking mounts scrape off cells and particles from a plant surface andand particles from a plant surface and suck the pieces into their mouths (thrips).suck the pieces into their mouths (thrips).
15. 15. Insect groupings by methods ofInsect groupings by methods of feeding, contd.feeding, contd. Siphoning insects have a straw-likeSiphoning insects have a straw-like mouth, called a proboscis, to suck upmouth, called a proboscis, to suck up nectar from flowers (moths, butterflies).nectar from flowers (moths, butterflies). Piercing-sucking have a proboscis toPiercing-sucking have a proboscis to pierce tissue surfaces, and feed on sappierce tissue surfaces, and feed on sap from the plant (scale insects).from the plant (scale insects). Sponging insects use sponge-likeSponging insects use sponge-like appendage to absorb liquid nourishmentappendage to absorb liquid nourishment (non-biting flies).(non-biting flies).
16. 16. Characteristics of InsectsCharacteristics of Insects Exoskeleton - aExoskeleton - a skeleton that isskeleton that is on the outside ofon the outside of an animal madean animal made of chitin.of chitin.
17. 17. Characteristics of InsectsCharacteristics of Insects Head -Head - Pair of compoundPair of compound eyes.eyes. Two sensoryTwo sensory appendagesappendages (antennae).(antennae).
18. 18. Characteristics of InsectsCharacteristics of Insects ThoraxThorax Has three body segmentsHas three body segments Has three pairs of legs, attached hereHas three pairs of legs, attached here Wings are attached here, depending on speciesWings are attached here, depending on species
19. 19. Characteristics, Contd.Characteristics, Contd. Abdomen attached to the thorax, segmented.Abdomen attached to the thorax, segmented.
20. 20. Life Cycles of InsectsLife Cycles of Insects The physical form of insects changes atThe physical form of insects changes at different stages of their lives. Thisdifferent stages of their lives. This process is calledprocess is called metamorphosismetamorphosis.. Not all insects go through metamorphosis;Not all insects go through metamorphosis; some insects molt a process where thesome insects molt a process where the insect outgrows its outer covering, shedsinsect outgrows its outer covering, sheds it, and grows a new one.it, and grows a new one. InstarsInstars are theare the stages of development between molts.stages of development between molts.
21. 21. Metamorphosis 3 stagesMetamorphosis 3 stages Larval stageLarval stage insect has soft, worm-like insect has soft, worm-like tubular body. Eat voraciously; capable oftubular body. Eat voraciously; capable of extensive damage to plants/crops.extensive damage to plants/crops. Pupal stagePupal stage relatively dormant, relatively dormant, intermediate stage between being a larvaintermediate stage between being a larva and an adult during which body tissuesand an adult during which body tissues are converted.are converted. Adult stageAdult stage insect mates, lays eggs, insect mates, lays eggs, cycle begins again.cycle begins again.
22. 22. Complete MetamorphosisComplete Metamorphosis
23. 23. Incomplete MetamorphosisIncomplete Metamorphosis Incomplete metamorphosis is a processIncomplete metamorphosis is a process whereby insects go from an egg to a formwhereby insects go from an egg to a form called a naiad which looks and functionscalled a naiad which looks and functions differently than an adult. When this growthdifferently than an adult. When this growth process is complete, the insect changes toprocess is complete, the insect changes to a winged adult. Examples: dragonflies,a winged adult. Examples: dragonflies, damselflies.damselflies.
24. 24. Incomplete MetamorphosisIncomplete Metamorphosis
25. 25. Gradual MetamorphosisGradual Metamorphosis In gradual metamorphosis, the immatureIn gradual metamorphosis, the immature insects hatches from an egg and looksinsects hatches from an egg and looks very much like the adult. These newlyvery much like the adult. These newly hatched insects are referred to ashatched insects are referred to as nymphs.nymphs. The nymph has different feeding habitsThe nymph has different feeding habits and may live in different places than theand may live in different places than the adults.adults. From the nymph stage, insects grow intoFrom the nymph stage, insects grow into adulthood. Ex: Roaches, Grasshoppers.adulthood. Ex: Roaches, Grasshoppers.
26. 26. Gradual MetamorphosisGradual Metamorphosis
27. 27. Insect PestsInsect Pests Phytophagous InsectsPhytophagous Insects (phyto = plant, (phyto = plant, phagous = eating).phagous = eating). Phytophagous Insects eat leaves, stems,Phytophagous Insects eat leaves, stems, fruits and roots of plants, and may alsofruits and roots of plants, and may also carry diseases caused by bacterial, viralcarry diseases caused by bacterial, viral and fungal pathogens.and fungal pathogens. PathogenPathogen a living, microscopic, disease- a living, microscopic, disease- producing agent.producing agent.
28. 28. PhytophagousPhytophagous InsectsInsects
29. 29. PredatoryPredatory InsectsInsects
30. 30. Insect Pests of AnimalsInsect Pests of Animals ParasitismParasitism a relationship beneficial to a relationship beneficial to one organism and harmful to the other.one organism and harmful to the other. ParasiteParasite an organism that practices an organism that practices parasitism; lives off of anotherparasitism; lives off of another organism/animal.organism/animal. Parasites may beParasites may be externalexternal oror internalinternal (live(live outside of the host, or inside of the host).outside of the host, or inside of the host).
31. 31. Challenges of Controlling InsectsChallenges of Controlling Insects Insects are prolific; reproduce often andInsects are prolific; reproduce often and produce large numbers of young.produce large numbers of young. One female insect may lay millions ofOne female insect may lay millions of eggs during her lifetime.eggs during her lifetime. Certain insects produce as many as 30Certain insects produce as many as 30 generations per year.generations per year.
32. 32. Insect Control MethodsInsect Control Methods Natural Control birds, bats, predatoryNatural Control birds, bats, predatory insects (ladybugs, wasps), mammals,insects (ladybugs, wasps), mammals, toads, frogs (amphibians), fish.toads, frogs (amphibians), fish. WeatherWeather DiseasesDiseases
33. 33. Insect Control Methods, Contd.Insect Control Methods, Contd. Chemical Control Chemical Control Has been used since ancient times. Example: 200Has been used since ancient times. Example: 200 B.C. Romans used bitumen on grape vines,B.C. Romans used bitumen on grape vines, hellebore to treat body lice; Chinese used arsenichellebore to treat body lice; Chinese used arsenic for pests; 1800s nicotine, copper sulphate,for pests; 1800s nicotine, copper sulphate, arsenic, paris green (copper compound); 1930 arsenic, paris green (copper compound); 1930 1950, DDT used to control disease carrying1950, DDT used to control disease carrying mosquitoes (malaria, yellow fever, typhus).mosquitoes (malaria, yellow fever, typhus).
34. 34. DDTDDT
35. 35. Problems with Chemical PesticidesProblems with Chemical Pesticides Can affect reproduction of animals;Can affect reproduction of animals; bioconcentrates buildup of pesticides inbioconcentrates buildup of pesticides in animals (particularly true of hydrocarbons).animals (particularly true of hydrocarbons). HydrocarbonsHydrocarbons last a very long time in thelast a very long time in the environment. (Hydrocarbons are a group ofenvironment. (Hydrocarbons are a group of chemical pesticides, including DDT, Chlordane,chemical pesticides, including DDT, Chlordane, Heptachlor and Toxaphene.) HydrocarbonsHeptachlor and Toxaphene.) Hydrocarbons dont break down into less harmful substancesdont break down into less harmful substances easily.easily.
36. 36. Problems with Chemical PesticidesProblems with Chemical Pesticides Hydrocarbons can enter, and be passed up, thruHydrocarbons can enter, and be passed up, thru the food chain.the food chain. Most hydrocarbons are now banned in theMost hydrocarbons are now banned in the United States.United States.
37. 37. Other Chemical PesticidesOther Chemical Pesticides OrganophosphatesOrganophosphates A class of insecticides which break downA class of insecticides which break down quickly and pose less threat to thequickly and pose less threat to the environment than do chlorinatedenvironment than do chlorinated hydrocarbons. Includes: diazinon, parathion,hydrocarbons. Includes: diazinon, parathion, malathion,malathion,
38. 38. Other Chemical PesticidesOther Chemical Pesticides Carbamates another class of chemicalCarbamates another class of chemical pesticides, less toxic to humans and otherpesticides, less toxic to humans and other warm-blooded animals. Includes carbaryl,warm-blooded animals. Includes carbaryl, (Sevin).(Sevin).
39. 39. Regulating PesticidesRegulating Pesticides The Environmental Protection AgencyThe Environmental Protection Agency (EPA) regulates pesticides.(EPA) regulates pesticides. New pesticides require about 10 years ofNew pesticides require about 10 years of testing before being approved for use.testing before being approved for use. Must be safe to manufacture.Must be safe to manufacture. Must not be harmful to the environmentMust not be harmful to the environment when used according to directions.when used according to directions. Crop pesticide residues must break downCrop pesticide residues must break down quickly.quickly. Must be labeled.Must be labeled.
40. 40. Integrated Pest ManagementIntegrated Pest Management The most modern method of pestThe most modern method of pest management is a multi-facetedmanagement is a multi-faceted (integrated) approach.(integrated) approach. IPM uses a wide variety of approaches inIPM uses a wide variety of approaches in coordination with each other.coordination with each other.
41. 41. IPM MethodsIPM Methods Cultural Methods control methods usedCultural Methods control methods used during a plants most vulnerable stage(s) ofduring a plants most vulnerable stage(s) of growth.growth. Cultural Methods are only used whenCultural Methods are only used when needed; require close monitoring of theneeded; require close monitoring of the plants for insect buildups. Also used forplants for insect buildups. Also used for controlling weeds. Example: plowingcontrolling weeds. Example: plowing under crops after harvest to destroyunder crops after harvest to destroy overwintering insects/habitats.overwintering insects/habitats.
42. 42. IPM Methods, Contd.IPM Methods, Contd. Insect Diseases andInsect Diseases and Predators thePredators the encouraging of birds andencouraging of birds and other predator insects toother predator insects to lower pest insectlower pest insect populations.populations. Examples:Examples: BacillusBacillus thuriengensisthuriengensis (Bt) spores(Bt) spores to control larval insectto control larval insect forms, parasitic waspsforms, parasitic wasps ((Encarsia sppEncarsia spp.).)
43. 43. IPM Methods, Contd.IPM Methods, Contd. PheromonesPheromones chemicals secreted by chemicals secreted by insects to communicate, for example, toinsects to communicate, for example, to attract a mate.attract a mate. Fields may be sprayed with pheromonesFields may be sprayed with pheromones to disorient males seeking females.to disorient males seeking females. Traps may be baited with pheromones toTraps may be baited with pheromones to interrupt reproduction.interrupt reproduction.
44. 44. IPM Methods, Contd.IPM Methods, Contd. Release of sterile males males treatedRelease of sterile males males treated with radiation or other treatment arewith radiation or other treatment are rendered sterile. They are then releasedrendered sterile. They are then released in large quantities. Mating yields noin large quantities. Mating yields no offspring.offspring.
45. 45. IPM Methods, Contd.IPM Methods, Contd. Use of Insect Resistant Plant Varieties Use of Insect Resistant Plant Varieties this involves using genetic engineering tothis involves using genetic engineering to create plants which insects dont like tocreate plants which insects dont like to feed on. This method holds greatfeed on. This method holds great potential for the future.potential for the future.