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Explore insect classification, growth, feeding, and management with expert Professor Emeritus Mike Wagner from Northern Arizona University. Understand the economic importance, beneficial aspects, and characteristics of insects. Delve into common insect orders, their attributes, and the concept of pest management for a well-rounded knowledge in entomology.
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Entomology For Master Gardeners Mike Wagner Regents Professor-Emeritus Northern Arizona University School of Forestry
Outline of Topics • Extent and Economic Importance • Insect Growth and Development • Insect Feeding / Mouthparts • Classification and Taxonomy • Movement and Spread • Population Dynamics / Concept of Pest • Diagnosing Insect Problems • Pest Management Approaches
Extent and Economic Importance • Major form of higher life • Attack all stages of all species • Damage equals harvest • Beneficial aspects
Beneficial Aspects • Pollination • Predators / Parasites • Human food • Biological control agents • Nutrient recycling • Insect products: honey, wax, shellac, dye • Conservation biology • Art and literature • Ecotourism- butterfly farms / exhibits
Characteristics of Insects • Arthropods: exoskeleton, jointed appendages • Adult Insects: • Head, thorax, abdomen • 1pair antennae • 3 pair legs • 2 pair of wings
Arthropods (Phylum Arthropoda: also include trilobites, horseshoe crabs, spiders, crustaceans, millipedes, centipedes) Insects are all in the HEXAPODA (class) Body with three distinct regions: head, thorax, and abdomen • Head: • Sensory Organ • a) Paired appendages (antennae) • b) Mouthparts • 2. Thorax: • Locomotion • Abdomen: • Reproductive and Digestive Head Abdomen Thorax
Thoracic legs • Prolegs
Thoracic legs Prolegs
Insect Relatives • Spiders, mites, ticks, centipedes, millipedes, sowbugs, snails, slugs • Bugs vs. “bugs”
Insect Growth and Development • Metamorphosis • Shed exoskeleton (molting) • Stages • Egg • Larva/nymph • Pupa • Adult • Instars
Wing pads • Wings Squash bug
Insect Growth and Development • Gradual: • Egg-nymph-adult • Nymph similar to adult • Ex. Aphids, scales, grasshoppers • Complete: • Egg-larva-pupa-adult • Larva does damage • Stages occur in different habitats • Ex. Beetles, butterflies, flies
Insect Feeding/Mouthparts • Chewing • Hard mandibles • Holes, tunnels, partial eaten leaves • Sucking • Straw (stylet), probosis • Curling, stunting, mottling, galls • Phytotoxic necrosis
4 Types of Mouth Parts Piercing/sucking
Chewing • Mouth Parts
Piercing/ sopping
Insect Classification Kingdom Phylum Class Order Family Genus Species
Insect Classification Kingdom Phylum Class Order Family Genus Species Animal Arthropods Insecta Coleoptera Scolytidae Dendroctonus brevicomis
Insect Classification Kingdom Phylum Class Order Family Genus Species Animal Arthropods Insecta Coleoptera Scolytidae Dendroctonus brevicomis keen pretty clothes out fill guys some
Taxonomic Classification • Common level: Order and Family • Basis for classification • Mouthparts • Type of wings • Type of metamorphosis
Common Insect Orders • Coleoptera: beetles, weevils • Dermaptera: earwigs • Diptera: flies, mosquitoes, gnats, midges • Hemiptera: true bugs • Homoptera: aphids, scales, leafhoppers, cicadas, whiteflies, mealy bugs • Hymenoptera: bees, wasps, ants, sawflies • Isoptera: termites
Coleoptera: beetles, weevils Complete Chewing Attributes: 400,000 species, hard front wings, beneficial and pest species, adults and larvae may feed on same host
Dermaptera: earwigs Gradual Chewing Attributes: front wings thickened, pest or beneficial (aphid predator), nocturnal, hide during the day
Diptera: flies, mosquitoes Larvae: chewing/hooks Adult: sponging, piercing Attributes: larvae legless, adults soft bodied, compound eye, one pair of wings, haltere, disease vectors, pest and beneficial Complete
Hemiptera: true bugs Gradual Attributes: nymphs resemble adults, many plant feeding pests, triangle on back, some predators, some disease vectors (Chagas disease) Piercing, sucking
Homoptera: aphids, leaf hoppers, white flies, scales Attributes: small soft bodied insects, unwinged forms, attack many vegetables, multiple generations, parthenogenesis, some disease vectors (CTV), greenhouse pests Gradual Sucking
Hymenoptera: bees, wasps, ants, sawflies Complete Attributes: legless larvae, adult stinger, two pair of membranous wings, ants with narrow waist, many species, pollinators, parasites, predators, sawflies are important defoliators, many species social Chewing
Isoptera: termites Attributes: soft bodied insects, winged or wingless, colonies occur in ground or in wood, drywood and subterranean termites, caste system, social Gradual Chewing
Lepidoptera: moths, butterflies Larvae: chewing Adults: sucking Attributes: caterpillars, adults have two pairs of scaled wings, many defoliators, adults feed on nectar, adults pollinate, basis for ecotourism Complete
Neuroptera: lacewings, antlions Complete Chewing Attributes: adults have 2 pairs of membranous wings, wings held rooflike, many species are predators
Orthoptera: grasshoppers, crickets, mantids, cockroaches Gradual Chewing Attributes: hard bodied adult, two pair of wings, front wings are hard, adults and nymphs cause damage, moderate pests
Siphonaptera: fleas Complete Sucking Attributes: wingless insects, live as ectoparasites on birds and mammals, body is laterally flattened, often jumping, important disease vectors, include plague and typhus
Thysanoptera: thrips Gradual Attributes: adults are minute soft bodied, two pairs of long wings, many feed on plants and especially flowers, cause cosmetic damage to fruit, some disease transmission Sucking
Common Insect Orders Continued • Lepidoptera: moths, butterflies • Neuroptera: lacewings, antlions • Odonata: dragonflies, damselflies • Orthoptera: grasshoppers, crickets, mantids, cockroaches • Siphonaptera: fleas • Thysanoptera: thrips • Thysanura: siverfish, firebrats
Movement and Spread • Adults have wings & legs • Adults can migrate • Larvae have legs • Larvae can walk • Larvae can move with wind
Population Dynamics • Insects have high reproductive potential • Can migrate; move with plants • Population limited by: • Environmental resistance • Host plant resistance • “if you build it, they will come” • Exotic (non-native) insects
Concept of a Pest • Interfere with objectives • Insects play vital ecological roles • 1% of insects are pests • Learn to live with damage- economic threshold
Diagnosing Insect Pest Problems • Recognize limitations • Most “sick” plants are abiotic • Identify the plant • Note the symptoms • Look for broad patterns • Within plant (leaf vs. fruit) • Across plant (spot vs. all plants) • Collect specimens
Diagnosing Insect Pest Problems Continued • Take notes • Formulate hypothesis • Important? Seek professional advice
Pest Managment • Integrated Pest Management • Legislative Control • Physical/Mechanical Control • Cultural Control • Biological Control • Chemical Control
IPM • Integrate all approaches to manage pest • Pest ID • Detection, monitoring models • Know insect biology • Ecologically sound
Legislative Control • Quarantine • State regulation- noxious weeds • Public education critical