Fundamental Principles of Pest Control Dr. Richard M. Houseman Department of Entomology University of Missouri-Columbia

Objectives Unit 1: pg. 1-39 “Applying Pesticides Correctly” Pests Identification and Damage Insects Plant Diseases Weeds Vertebrates Pest Management Pesticides Mode of Action

Core Manual ‘Learning Objectives’ ‘Terms to Know’ Clues to what is important ‘Terms to Know’ Definitions of common words ‘Test Your Knowledge’ Example test questions

Pest Management (pg.5) Objectives Prevention = keep from becoming a problem Suppression = reducing to an acceptable level Eradication = destroying an entire pest population

Management Strategies Mechanical Exclusion/removal Heat/cold Biological Natural enemies, microbials Pheromones/hormones Cultural Tilling, burning, mowing, flooding Crop rotation, trap crops Planting/harvest timing

Management Strategies Sanitation Eliminate breeding sites Remove pathogens/sources Disinfect equipment/tools Host Resistance Using disease-resistant varieties Genetics Manipulate host resistance Sterility in pest

Management Strategies Chemical The use of natural or synthetic substances that directly cause the death, repulsion, or attraction of pests. Considerations Mode of Action Persistence Non-target effects Resistance

Mode of Action Mode of Action The way a chemical kills a pest. Examples: Repellents, poisons, eradicants, systemics

Persistence Persistence The length of time a chemical is active after being applied. Categories: Non-Persistent Kills the pest, breaks down in a relatively short period of time Persistent Residues remain active for period of time after application

Non-Target Effects Non-Target Effects Pesticide effects on non-pest organisms. Potential risks: May kill beneficial organisms May create new pests Ex.-Killing natural enemies of a non-pest.

Resistance Resistance Lessening of the effectiveness of a pesticide for reducing the pest population Principles: Chemicals kill only susceptible pests Survivors pass traits for survival to their offspring Resistance develops over generations

Resistance To promote: To limit: Use same pesticide repeatedly Use over large areas Use highly residual chemicals To limit: Rotate pesticides Target applications Use persistent chemicals wisely

Pests (pg.3) A Pest is any unwanted organism Based on what organism does, not on what they are. Compete for food or water Cause injury, disease, or annoyance

Pests (pg.3) Types of Pests Continuous = nearly always present Sporadic = occasionally present; migratory/cyclical Potential = not normally pests, require control only in certain situations

Pest Identification (pg.3) How to Identify? Physical features Damage or Symptoms Why Identify? Pests differ in their habitats, behavior, life cycles, and susceptibility to control methods.

Insect & Insect-like Pests (pg.6) Physical Features Segmented bodies Jointed appendages Exoskeleton made of chitin Bilateral symmetry

Insects Three body regions (pg.6) Head Thorax Abdomen 1 Pair of antennae Various mouthparts Thorax 3 pairs of legs 2 pairs of wings Abdomen Body systems

Insects Life Cycle (pg.7) Metamorphosis None Gradual Incomplete Only change is size Gradual Egg, nymph, adult Incomplete Egg, nymph, adult (H2O) Complete Egg, larva, pupa, adult

Insect-like Groups (pg.8) Arachnids Spiders, mites, ticks 2 regions, 8 legs Crustaceans Pillbugs 3 regions, >8 legs Chilopods Centipedes Many regions & legs Diplopods Millipedes

Insect-like Groups Nematodes Mollusks Look like insect larvae Microscopic roundworms Mollusks Slugs, snails Look like insect larvae Non-segmented No metamorphosis

Insect Pests of Plants (pg.10) Types of damage Leaf eating Plant-sucking Internal feeding Stem boring Root feeding

Pests of Animals (pg.11) Types of damage Stinging Biting Blood sucking Toxin injecting

Insecticides (pg.15) Modes of Action Repellents Disrupters Poisons Keep insects away from an area or host Disrupters Interfere mechanically with body function Poisons Deactivate biological systems in the body Stomach = must be eaten Contact = must be touched

Plant Pathogens (pg.16) Plant Disease Any condition that causes a plant to function or appear different from normal

Plant Diseases (pg.16) Plant Responses to Disease Agents Overdeveloped tissues ie. galls, leaf curls, swelling Underdeveloped tissues ie. stunting, lack of chlorophyll Death of Tissues ie. leaf spot, wilting, blight, cankers

Plant Diseases Pathogens include: Fungi Bacteria Viruses Mycoplasmas

Fungi (pg.16) Feed on other organisms Reproduce by spores Most are beneficial Decomposers A few parasites Feed on living plant tissues Reproduce by spores Microscopic, resistant stage

Fungi Symptoms Soft rot of fruit Rusts, smuts Curling, powdery mildew of leaves Spots on leaves

Bacteria (pg.17) Microscopic Symptoms Reproduce by cell division Blights, spots , rots Reproduce by cell division

Viruses (pg.17) Sub-microscopic Symptoms Reproduce inside host cell Abnormal growth, mosaics Reproduce inside host cell Vector transfer

Mycoplasmas (pg.17) Smallest living things Symptoms Plant-feeders Symptoms Yellow, stunting Reproduce independently Insects, mites, grafting

Fungicides & Bactericides Modes of Action (pg.20) Protectants Applied before or during initial infection Eradicants Applied after infection Systemics Internal transport to all tissues of plant

Weeds (pg.21) A weed is any plant growing where it is not wanted. Effects: Compete for resources Contaminate harvest Harbor pests or release toxins Look ‘bad’

Weeds Development (pg.21) Seedling Vegetative Reproductive Maturity Producing leaves, stems, roots Reproductive Producing flowers, seeds Maturity

Weeds Life Cycles (pg.21) Annuals = one year Biennials = two years Perennials = more that two years

Weed Identification (pg.22) Grasses Narrow, parallel veins, round stems Sedges Narrow, parallel veins, triangular stems Broadleaves Fan-like, branching veins

Herbicides (pg.25) Modes of Action or or Contact Translocated kills parts of plant the chemical touches Translocated absorbed and distributed throughout the plant Selective kills only undesireable plants Non-selective kills all plants in an area or or

Herbicides

Herbicides (pg.26) Modes of Action (cont’) or Foliar Soil Example: Applied to leaves of the weed (foliage) Soil Applied to the ground around the weed Example: 2,4-D is a foliar-translocated-nonpersistent-selective or

Vertebrates (pg.29) Have backbones Many potential pests Various situations and impacts. Eat crops, kill livestock, transmit disease, contamination, etc.

Poisons (pg.30) Few pesticides available Rodenticides: most commonly-used Piscicides Avicides Usually highly toxic to humans

Summary Identification of the pest and an understanding of its biology is important. The best pest management programs combine all of the available control tactics. When using chemicals, it is important to understand their mode of action, persistence, risk of resistance, and their effect on non-target organisms.