Insects Basics - Tulsa Master Gardeners

Oklahoma Master Gardeners Basic Entomology for the Home and Landscape

Eric J. Rebek

Dept. of Entomology and Plant Pathology

MG Questions and Answers • How can I manage insect pests without insecticides? • Why are my pine trees dying? • Do some plants repel mosquitoes? • Why doesn’t this insecticide work? Oklahoma State University

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Keys to Insect Management Know your landscape

Know your adversary Know your tools for control Oklahoma State University

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Know Your Landscape • Preemptive gardening

– good first step in keeping many problems from ever occurring (i.e., preventative maintenance) – proper plant material – proper site identification – proper fertility and watering – overall, good horticultural practices to maintain plant health

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Know Your Landscape • Some insects are commonly associated with certain plants

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Know Your Landscape • Some of these close associations create a nuisance for the home or landscape

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Know Your Landscape • Location of materials in the landscape can affect potential pest problems

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Know Your Adversary Why Study BUG Science?

• Proper ID • Associate injury symptoms with pest • Selection of proper control strategy Oklahoma State University

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Classification of Japanese Beetle       

Kingdom Phylum Class Order Family Genus Species

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Animalia Arthropoda Insecta Coleoptera Scarabaeidae

Popillia japonica

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The Arthropods Phylum Arthropoda (ahr thrŏ pod a) • The most abundant, diverse life form on the planet (3/4 of known animal species) • Our chief competitor for food, and a major source of potential health problems and annoyance • Most are NOT a problem for us Oklahoma State University

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The Arthropods • 100,000 species in North America • 1,000 species in a typical backyard • Mostly beneficial or harmless – Pollination – Food for birds, fish, frogs, etc. – Produce honey, wax, shellac, silk

• Less than 2% are pests

– Destroy food crops, ornamentals – Attack humans, livestock, and pets – Transmit disease

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Arthropod Diversity

Other arthropods Other insects Hemiptera Diptera Hymenoptera

Coleoptera Lepidoptera

What Is an Arthropod? All arthropods have: • Skeleton on the outside of the body • Distinct body segmentation • Paired, jointed appendages • Dorsal, tubular heart valves

• Double, ventral nerve chord • Open circulatory system Oklahoma State University

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Classes of Arthropods • Malacostraca (crayfish, lobsters, sowbugs pillbugs)  crustaceans • Arachnida (spiders, mites, ticks, scorpions) • Chilopoda (centipedes) • Diplopoda (millipedes) • Insecta (true bugs, beetles, butterflies, wasps, fleas, grasshoppers, silverfish, etc.) Oklahoma State University

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The Arachnids Class Arachnida (a-rach’-nid-a) – Two body regions (cephalothorax + abdomen) – No antennae, never winged – 4 pairs of legs Tick

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Mite

Harvestman

Spider

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Scorpion

The Chilopods Class Chilopoda (chi lo po da) Centipedes – Two main body regions – Flattened body – 30 to 340 legs (1 pair per body segment) – 1 pair antennae – Predaceous, can be venomous Oklahoma State University

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The Diplopods Class Diplopoda (dip lo po da) Millipedes – – – –

2 body regions Body generally rounded 1 pair of antennae 80-400 legs (2 pair per body segment) – Feed on decaying organic matter – Often coil when disturbed Oklahoma State University

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The Insects Class Insecta (in sec ta) • Beetles, wasps, butterflies, cicadas, grasshoppers, roaches • 3 body regions (head + thorax + abdomen) • 3 pairs of legs • 1 pair of antennae • 0, 1 or 2 pair of wings Oklahoma State University

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Insect Physiology 101 The insect body is made of a substance called chitin; it must be shed for the insect to grow

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Insect Growth Metamorphosis • Series of changes an insect passes through in its growth and development • Growth and development occur through the process of ecdysis (shedding the exoskeleton, or molting) • Each molt allows insect to get bigger, change shape, and mature Oklahoma State University

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Insect Growth • Ametabolous Growth – Increase in size, but no changes in characteristics of the insect

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Insect Growth • Ametabolous Growth – – – –

Protura (Proturans) Diplura (Diplurans) Thysanura (Silverfish) Collembola (Springtails)

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Insect Growth • Paurometabolous Development = gradual metamorphosis – Three life stages (egg, nymph, adult) – Change in size, and addition of adult structures, such as reproductive organs, wings.

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Insect Growth • Gradual Metamorphosis -

Isoptera (Termites) Dermaptera (Earwigs) Phthiraptera (Lice) Psocoptera (Booklice) Zoraptera (Angel insects)

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Insect Growth • Gradual Metamorphosis - Orthoptera (Grasshoppers, Roaches, Walkingsticks, Mantids) - Thysanoptera (Thrips) - Hemiptera (True Bugs, Aphids, Scales, Leafhoppers, Plant Hoppers, Whiteflies) Oklahoma State University

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Insect Growth • Hemimetabolous Development = simple (incomplete) metamorphosis – Three life stages (egg, naiad, adult) – Immature stage is aquatic

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Insect Growth • Incomplete Metamorphosis - Ephemeroptera (Mayfly) - Odonata (Dragonfly) - Plecoptera (Stonefly)

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Insect Growth • Holometabolous Development = complete metamorphosis – Four life stages (egg, larva, pupa, adult)

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Insect Growth • Complete Metamorphosis - Neuroptera (Lacewings) -

Coleoptera (Beetles) Mecoptera (Scorpionfly) Lepidoptera (Butterfly) Diptera (True Fly) Siphonaptera (Flea) Hymenoptera (Ants, Bees, Wasps)

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Insect Orders • Insects can be grouped into orders quite easily with a bit of practice. Key in on the following: – – – –

Wing type and number Mouthparts Type of development Other body structures (legs, antennae, etc.)

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Insect Mouthparts Chewing

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Insect Mouthparts Chewing-lapping

Honeybee Oklahoma State University

Sponging

House fly Oklahoma Master Gardeners

Insect Mouthparts Piercing-sucking

Leafhopper

Stable Fly

Mosquito Flea

Louse Oklahoma State University

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Insect Mouthparts Siphoning

Butterfly

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Rasping

Thrips

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Insect Wings

True bug - hemelytra

Grasshopper - tegmina

Thrips – fringed Beetle - elytra Oklahoma State University

Wasp – membranous Oklahoma Master Gardeners

Antennae

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Legs

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Major Groups of Insects • Coleoptera (= sheath-winged) - Beetles Complete metamorphosis Chewing mouthparts Hardened wing covers (elytra) on adults, antennae are various Oklahoma State University

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Major Groups of Insects • Diptera (= two-winged) - Flies, gnats, mosquitoes Complete metamorphosis Mouthparts various 1 pair of membranous wings, and 1 pair of little knobs called halteres (= hindwings) Oklahoma State University

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Major Groups of Insects • Hemiptera (= half-winged) - True bugs Gradual metamorphosis

Piercing-sucking mouthparts 2 pairs of wings with hemelytra (outer wings); half membranous and half leathery Oklahoma State University

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Major Groups of Insects • Hemiptera - Aphids, scales, whiteflies, leafhoppers, cicadas Gradual metamorphosis Piercing-sucking mouthparts 2 pairs of clear wings, some wingless Some reproduce without males Oklahoma State University

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Major Groups of Insects • Hymenoptera (= membrane-winged) Ants, bees, wasps Complete metamorphosis

Chewing mouthparts Membranous wings

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Major Groups of Insects • Lepidoptera (= scale-winged) Butterflies, moths, skippers Complete metamorphosis

Siphoning mouthparts (adult), chewing mouthparts (larva) 2 pairs of wings with colored scales Oklahoma State University

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Major Groups of Insects • Orthoptera (= straight-winged) Grasshopper, cricket, praying mantis, walkingstick, cockroach Gradual metamorphosis Chewing mouthparts Outer wings leathery, inner ones membranous Oklahoma State University

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Major Groups of Insects • Neuroptera (= nerve-winged) - Lacewings, antlions, snakeflies, mantispids, dobsonflies Complete metamorphosis

Chewing mouthparts (adult), piercing mouthparts (larva) Membranous wings with many veins Most are predaceous Oklahoma State University

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Major Groups of Insects • Thysanoptera (= fringe-winged) – thrips Gradual metamorphosis Rasping-sucking mouthparts 2 pairs of “feathery” wings Oklahoma State University

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