Principles of Entomology ENY 3005/5006 Dr. Miller Fall 2011 Introduction Sheet Name Major Year in school What do you want to be doing in: 5 years? 10 years? Why did you take this class? Which topic on the syllabus sounds the most interesting to you? Lecture 1. Insect Significance and Diversity Each week Review the questions and objectives on the study guide before each lecture. Bonus points available at random (up to 20) Photo: CW Miller WHY STUDY INSECTS? Answer: Insects are by far the most successful organisms on this planet There are more kinds of insects than any other group of organisms 1
RELATIVE NUMBER OF SPECIES OF ARTHROPODS, OTHER ANIMALS, AND PLANTS WHY STUDY INSECTS? Non-insect arthropods Plants Insects Answer: Insects are by far the most successful organisms on this planet There are more kinds of insects than any other group of organisms Insects dominate every ecosystem, except one INSECTS PLAY ESSENTIAL, IRREPLACEABLE ROLES IN ECOSYSTEMS 1) Nutrient recycling 2
INSECTS PLAY ESSENTIAL, IRREPLACEABLE ROLES IN ECOSYSTEMS 1) Nutrient recycling 2) Plant pollination Photo: Mike Scharf INSECTS PLAY ESSENTIAL, IRREPLACEABLE ROLES IN ECOSYSTEMS 1) Nutrient recycling 2) Plant pollination 3) Maintenance of plant community composition and structure INSECTS PLAY ESSENTIAL, IRREPLACEABLE ROLES IN ECOSYSTEMS 1) Nutrient recycling 2) Plant pollination 3) Maintenance of plant community composition and structure 4) Supporting insectivorous animals 3
RELATIVE NUMBER OF SPECIES OF ARTHROPODS, OTHER ANIMALS, AND PLANTS Non-insect arthropods Plants Insects 4
80 percent of the world's population eats insects intentionally. 100 percent eat insects unintentionally. If Americans tolerated more insects in their food, farmers could significantly reduce the amount of pesticides applied to their crops each year. By weight, termites, grasshoppers, caterpillars, weevils, house flies and spiders are better sources of protein than beef, chicken, pork or lamb. Source: Food Insects Newsletter A palm weevil larva, Rhynchophorus phoenicis (Coleoptera: Curculionidae) Eaten in Angola Yum A witchety grub (Leptdoptera: Cossidae) SOME INSECTS CAN CAUSE BIG PROBLEMS Mopane worm very common in Africa Imbrasia belina Check out page 20-21 (ed. 4) or page 19 (ed. 3) 1) Psychological 2) Nuisance e.g. Common bed bug, Cimex lectularius 3) Venoms/Allergens e.g. Bee sting allergies 4) Causes of disease 5) Disease vectors 5
INSECTS PLAY ESSENTIAL, IRREPLACEABLE ROLES IN ECOSYSTEMS 1) Nutrient recycling 2) Plant pollination 3) Maintenance of plant community composition and structure 4) Supporting insectivorous animals INSECT BIODIVERSITY LEAFCUTTER ANTS 1 million species of insects have been described 6
LEAFCUTTER ANTS Large nests excavate 40 tons of soil Some colonies have millions of individuals Compete with cattle on grasslands In certain locations responsible for 80% of leaf damage 20% of all leaf decomposition in S. America Use 50-70% of all tropical plant species (polyphagous) INSECT BIODIVERSITY 4 orders have especially high species richness Insect Biodiversity Insect Biodiversity an inordinate fondness for beetles J.B.S. Haldane Why are there so many species of insects? Insects are small Sensory and neuro-motor sophistication Short generation time Coevolution/antiquity Metamorphosis 7
Why are there so many species of insects? Insects are small Sensory and neuro-motor sophistication Short generation time Coevolution/antiquity Metamorphosis Flight Insect Biodiversity Insect Biodiversity As a result: Rapid speciation or maintenance of existing species (lower rate of extinction) Naming and classification NAMING AND CLASSIFICATION Examples of scientific names: South African ladybird beetle Chilomenes lunulata (Coleoptera: Coccinellidae) NAMING AND CLASSIFICATION Examples of scientific names: Heliconia bug Leptoscelis tricolor (Hemiptera: Coreidae) Class: Insecta Phylum: Arthropoda Insects are animals! Know the orders of insects (e.g. Diptera, Coleoptera) 8
Insect conservation INSECT CONSERVATION There are a lot of insects in the world, do I really need to worry about species going extinct? Queen Alexandra s birdwing butterfly, Ornithoptera alexandrae Colorado potato beetle Leptinotarsa decemlineata INSECT CONSERVATION Insect conservation or not? We know few species well (pests), but we know little or nothing about most beneficial or neutral insects Agraeus (Elateridae) Myanmar Cyathiger (Pselaphinae) Sumatra Jewel beetles, Family Buprestidae $40 Insect conservation Insect conservation 9
Insect conservation FOR THE ORDER QUIZ HEXAPOD ORDER STUDY GUIDE Scientific order names Common order names S Are they hemimetabolous, ametabolous, or holometabolous? Are they pterygote or apterygote? Are they paleoptera or neoptera? All facts on study guide (recognize them) Definitions of the terms above Queen Alexandra s birdwing butterfly, Ornithoptera alexandrae FOR THE QUIZ Example: Order: Ephemeroptera Order: Mayflies Hemimetabolous Pterygote Paleoptera Fact: Most adults are delicate insects with a very short lifespan. They do not feed (mouthparts are vestigial), and some species emerge, reproduce, and die in a single day. 10