oklahoma master gardeners basic entomology for the home and landscape eric j. rebek dept. of...

Oklahoma Master Gardeners

Basic Entomology for the Home and

Landscape

Eric J. RebekDept. 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?

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Keys to Insect Management

Know your adversary

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Know your landscape

Know your tools for control

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?

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

Classification of Japanese Beetle

Kingdom Animalia Phylum Arthropoda Class Insecta Order Coleoptera Family Scarabaeidae Genus Popillia Species japonica

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The Arthropods

• 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

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Phylum Arthropoda (ahr thrŏ pod a)

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

Coleoptera

LepidopteraHymenoptera

Diptera

Hemiptera

Other insects

Other arthropods

What Is an Arthropod?

• Skeleton on the outside of the body

• Distinct body segmentation

• Paired, jointed appendages

• Dorsal, tubular heart valves

• Double, ventral nerve chord

• Open circulatory system

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All arthropods have:

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.)

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The Arachnids

– Two body regions (cephalothorax + abdomen)

– No antennae, never winged– 4 pairs of legs

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Class Arachnida (a-rach’-nid-a) Mite

ScorpionSpiderTick

Harvestman

The Chilopods

– Two main body regions– Flattened body– 30 to 340 legs (1 pair

per body segment)– 1 pair antennae– Predaceous, can be venomous

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Class Chilopoda (chi lo po da)Centipedes

The Diplopods

– 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

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Class Diplopoda (dip lo po da)Millipedes

The Insects

• Beetles, wasps, butterflies, cicadas, grasshoppers, roaches

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Class Insecta (in sec ta)

• 3 body regions (head + thorax + abdomen)• 3 pairs of legs• 1 pair of antennae• 0, 1 or 2 pair of wings

Insect Physiology 101

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

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

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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

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

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• Gradual Metamorphosis

Insect Growth

- Orthoptera (Grasshoppers, Roaches, Walkingsticks, Mantids)

- Thysanoptera (Thrips)- Hemiptera (True Bugs,

Aphids, Scales, Leafhoppers, Plant Hoppers, Whiteflies)

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• Gradual Metamorphosis

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.)Oklahoma State University Oklahoma Master Gardeners

Insect Mouthparts

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Chewing

Insect Mouthparts

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Chewing-lappingSponging

Honeybee House fly

Insect Mouthparts

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Piercing-sucking

Leafhopper

Flea

Mosquito

Louse

Stable Fly

Insect Mouthparts

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SiphoningRasping

ThripsButterfly

Insect Wings

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Beetle - elytra

Thrips – fringed

True bug - hemelytra Grasshopper - tegmina

Wasp – membranous

Antennae

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Legs

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Major Groups of Insects

• Coleoptera (= sheath-winged) - Beetles

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Complete metamorphosis

Chewing mouthparts

Hardened wing covers (elytra) on adults, antennae are various

Major Groups of Insects

• Diptera (= two-winged) - Flies, gnats, mosquitoes

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Complete metamorphosis

Mouthparts various

1 pair of membranous wings, and 1 pair of little knobs called halteres (= hindwings)

Major Groups of Insects

• Hemiptera (= half-winged) - True bugs

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Gradual metamorphosis

Piercing-sucking mouthparts

2 pairs of wings with hemelytra (outer wings); half membranous and half leathery

Major Groups of Insects

• Hemiptera - Aphids, scales, whiteflies, leafhoppers, cicadas

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Gradual metamorphosis

Piercing-sucking mouthparts

2 pairs of clear wings, some wingless

Some reproduce without males

Major Groups of Insects

• Hymenoptera (= membrane-winged) - Ants, bees, wasps

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Complete metamorphosis

Chewing mouthparts

Membranous wings

Major Groups of Insects

• Lepidoptera (= scale-winged) - Butterflies, moths, skippers

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Complete metamorphosis

Siphoning mouthparts (adult), chewing mouthparts (larva)

2 pairs of wings with colored scales

Major Groups of Insects

• Orthoptera (= straight-winged) - Grasshopper, cricket, praying mantis, walkingstick, cockroach

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Gradual metamorphosis

Chewing mouthparts

Outer wings leathery, inner ones membranous

Major Groups of Insects

• Neuroptera (= nerve-winged) - Lacewings, antlions, snakeflies, mantispids, dobsonflies

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Complete metamorphosis

Chewing mouthparts (adult), piercing mouthparts (larva)

Membranous wings with many veins

Most are predaceous

Major Groups of Insects

• Thysanoptera (= fringe-winged) – thrips

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Gradual metamorphosis

Rasping-sucking mouthparts

2 pairs of “feathery” wings