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 Oklahoma Master Gardeners Keys to Insect Management Know your landscape Know your adversary Know your tools for control Oklahoma State University Oklahoma Master Gardeners 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 Oklahoma State University Oklahoma Master Gardeners Know Your Landscape • Some insects are commonly associated with certain plants Oklahoma State University Oklahoma Master Gardeners Know Your Landscape • Some of these close associations create a nuisance for the home or landscape Oklahoma State University Oklahoma Master Gardeners Know Your Landscape • Location of materials in the landscape can affect potential pest problems Oklahoma State University Oklahoma Master Gardeners Know Your Adversary Why Study BUG Science? • Proper ID • Associate injury symptoms with pest • Selection of proper control strategy Oklahoma State University Oklahoma Master Gardeners Classification of Japanese Beetle Kingdom Phylum Class Order Family Genus Species Oklahoma State University Animalia Arthropoda Insecta Coleoptera Scarabaeidae Popillia japonica Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma State University Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma Master Gardeners The Arachnids Class Arachnida (a-rach’-nid-a) – Two body regions (cephalothorax + abdomen) – No antennae, never winged – 4 pairs of legs Tick Oklahoma State University Mite Harvestman Spider Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma Master Gardeners Insect Physiology 101 The insect body is made of a substance called chitin; it must be shed for the insect to grow Oklahoma State University Oklahoma Master Gardeners 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 Oklahoma Master Gardeners Insect Growth • Ametabolous Growth – Increase in size, but no changes in characteristics of the insect Oklahoma State University Oklahoma Master Gardeners Insect Growth • Ametabolous Growth – – – – Protura (Proturans) Diplura (Diplurans) Thysanura (Silverfish) Collembola (Springtails) Oklahoma State University Oklahoma Master Gardeners 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. Oklahoma State University Oklahoma Master Gardeners Insect Growth • Gradual Metamorphosis - Isoptera (Termites) Dermaptera (Earwigs) Phthiraptera (Lice) Psocoptera (Booklice) Zoraptera (Angel insects) Oklahoma State University Oklahoma Master Gardeners Insect Growth • Gradual Metamorphosis - Orthoptera (Grasshoppers, Roaches, Walkingsticks, Mantids) - Thysanoptera (Thrips) - Hemiptera (True Bugs, Aphids, Scales, Leafhoppers, Plant Hoppers, Whiteflies) Oklahoma State University Oklahoma Master Gardeners Insect Growth • Hemimetabolous Development = simple (incomplete) metamorphosis – Three life stages (egg, naiad, adult) – Immature stage is aquatic Oklahoma State University Oklahoma Master Gardeners Insect Growth • Incomplete Metamorphosis - Ephemeroptera (Mayfly) - Odonata (Dragonfly) - Plecoptera (Stonefly) Oklahoma State University Oklahoma Master Gardeners Insect Growth • Holometabolous Development = complete metamorphosis – Four life stages (egg, larva, pupa, adult) Oklahoma State University Oklahoma Master Gardeners Insect Growth • Complete Metamorphosis - Neuroptera (Lacewings) - Coleoptera (Beetles) Mecoptera (Scorpionfly) Lepidoptera (Butterfly) Diptera (True Fly) Siphonaptera (Flea) Hymenoptera (Ants, Bees, Wasps) Oklahoma State University Oklahoma Master Gardeners 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 Chewing Oklahoma State University Oklahoma Master Gardeners 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 Oklahoma Master Gardeners Insect Mouthparts Siphoning Butterfly Oklahoma State University Rasping Thrips Oklahoma Master Gardeners Insect Wings True bug - hemelytra Grasshopper - tegmina Thrips – fringed Beetle - elytra Oklahoma State University Wasp – membranous Oklahoma Master Gardeners Antennae Oklahoma State University Oklahoma Master Gardeners Legs Oklahoma State University Oklahoma Master Gardeners Major Groups of Insects • Coleoptera (= sheath-winged) - Beetles Complete metamorphosis Chewing mouthparts Hardened wing covers (elytra) on adults, antennae are various Oklahoma State University Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma Master Gardeners Major Groups of Insects • Hymenoptera (= membrane-winged) Ants, bees, wasps Complete metamorphosis Chewing mouthparts Membranous wings Oklahoma State University Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma Master Gardeners 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 Oklahoma Master Gardeners Major Groups of Insects • Thysanoptera (= fringe-winged) – thrips Gradual metamorphosis Rasping-sucking mouthparts 2 pairs of “feathery” wings Oklahoma State University Oklahoma Master Gardeners