What is a pest? How Insects Become Pests. How do insects become pests? Problems with Pesticides. What is most commonly used to control insect pests?

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1 What is a pest? How Insects Become Pests How do insects become pests? Introduction outside of native range Becomes disease vector Plant or animal (inclu. human) disease vector Host shift in native insect (e.g., CPB, apple maggot, Helicoverpa) Vast areas of crop monocultures Lots of food for insect; fewer natural enemies Agricultural practices e.g., continuous cropping; pesticides eliminate natural enemies What is most commonly used to control insect pests? Problems with Pesticides Resistance Destruction of non-target organisms natural enemies, pollinators, soil arthropods, wildlife Secondary pest outbreaks Environmental safety Human health and safety 1

2 Cumulative increase in the number of arthropod species known to be resistant to one or more pesticides In North America, who misuses pesticides the most? Note: Pesticides are still the main pest control tactic used today What pesticides do you use? Mildew control in the shower Flea powder on pets Household bug sprays Wood treatment Repellents Detergent Integrated Pest Management (IPM) Developed in response to problems created by over-reliance on pesticides Many definitions of Integrated Pest Management (IPM) IPM is a sustainable approach to managing pests that combines biological, cultural, physical, and chemical, and other control tools in a way that minimizes economic, health, and environmental risks. Some Settings for IPM Crop agriculture Animal agriculture Forestry/natural areas Food service/storage/restaurants Public facilities/hotels/apartments/schools Landscapes/golf courses/parks/zoos Homes (inside and outside) 2

3 How do you know when an insect infestation is causing a problem that needs correcting? Basic Component of IPM: Economic Threshold An objective way to make pest control decisions Economic Threshold Concept The level of a pest population at which an economic loss will be incurred if no action is taken to control a pest. i.e., it does not pay to take any action against a pest that will not cause an economic loss in the crop. Economic Threshold Concept Economic Injury Level (EIL) Pest density at which the loss caused by the pest equals the cost of available control measures; Lowest population level that will cause economic damage Non-economic insect Occasional pest Economic Threshold Concept Economic Threshold (ET) Pest density at which control measures should be applied to prevent an increasing pest population from reaching the EIL; Represents the time when control measures should be implemented Perennial pest Severe or key pest 3

4 4/3/11 Threshold surprises Pest Monitoring/Sampling Citrus red mite lemon Sou. Calif. Method(s) for assessing damage levels or pest population levels Used to tell if ET has been reached Traps (pheromones, baits, sticky traps, etc.) Sampling plans Cucumber beetles on young pumpkin plants NY IPM Tactics Cultural Control Physical/mechanical Control Chemical Control Host-Plant Resistance Biological Control Genetic Control Regulatory Control IPM Tactics: Cultural Control IPM Tactics: Cultural Control The use of farming or cultural practices associated with crop production that make the environment less favorable for survival, growth, or reproduction of the pest. Ware, 2000 Melon trap crop around cotton field for whitefly management Crop rotation (esp. for monophagous insects) Trap crops Planting/Harvest time Destroy crop residues 4

5 4/3/11 IPM Tactics: Physical Control Application of direct or indirect measures that kill the pest, exclude it from an area, or adversely alter the pest s environment. Examples: Hand picking, trapping, sticky bands, flooding Often labor intense Barrier: Bed Nets (often insecticide-treated) Propane flaming for Colorado Potato Beetles Reflective surfaces/strips for birds, aphids, thrips, others IPM Tactics: Chemical Control Natural or synthetic compounds Natural may be derived from plants or microorganisms Entry into insect via contact, inhalation, or ingestion Direct contact or residues Various pesticide formulations and application methods Can often be integrated with biological control 5

6 4/3/11 Benefits from Insecticides Increased yield/acre Cheaper food Greater variety of food Control of human & animal disease More aesthetically pleasing food Control of household pests Less naturally contaminated foods (fungus) Ease of harvest Military use Forest preservation Sex Pheromones (synthetically produced) Monitoring pest levels and/or activity Routinely used in modern agriculture Mating disruption Mass-trapping Important Legislation Federal Insecticide, Fungicide, & Rodenticide Act (FIFRA) Food & Drug Comestic Act (FDCA) Food Quality Protection Act (FQPA) Sex Pheromones: Mating Disruption Disrupt mating by imitating the sex pheromone Very species specific Various mechanisms for release (puffers, bands, microcapsule spray) IPM Tactic: Host-Plant Resistance The development and use of plants that are resistant to attack by insects and/or disease organisms. Example: Grape rootstocks in the United States are highly resistant to phylloxera and are grafted onto desired European varieties. 6

7 4/3/11 Genetically Modified Organisms Bt Cotton and Corn Roundup ready cotton, corn, soybean, canola, rice, sugar beets, alfalfa, lettuce, and wheat Types of Natural Enemies IPM Tactic: Biological Control Biological control is the action of parasitoids, predators, and/or pathogens in maintaining the density of a pest at a level low enough such that economic damage does not occur. Biological Control Approaches Predators Eat more than one pest as they develop to adult Parasitoids Eat only a single pest as they develop to adult Classical Biological Control Augmentation Biological Control Conservation Biological Control Pathogens Cause disease in pests A) Classical biological control Vedalia beetle, Rodolia cardinalis Predator of cottony-cushion scale Serious pest of citrus in CA in late 1800 s 7

8 B) Augmentation Biological Control Augmentative biological control in greenhouse crops: Predaceous mite releases for thrips C) Conservation Biological Control Conserve existing complex of natural enemies Examples: Orchard ground covers Raspberry plantings around grape vines IPM Tactic: Regulatory Control The prevention of the entry and establishment of undesirable plant and animal pests in a country or area and the eradication, containment, or suppression of pests already established in limited areas (quarantines) Ware, 2000 Quarantines: Ex.: Asian Longhorned Beetle Ex.: Emerald Ash Borer 8

9 Quarantines California: Gypsy moth Japanese beetle UK: Colorado potato beetle IPM Questions Is it a pest? How to detect or monitor pest levels? Control options? Cultural Physical/mechanical Pesticides Plant resistance Biological control Thought experiment: Assume you have no pesticides - how would you manage the pest? 9