Pest Management. Objectives 3/30/2012. Spring How do we know when to start taking action against a pest?

Transcription

1 Spring 2012 Pest Management Spring 2012 Pest Management Part I: Dr. Koehler on April 5 th Part II: Dr. Miller on April 10 th These are the slides for April 10 th. To prepare for Dr. Koehler s lecture, read the files posted on the website. What is a pest? What is a pest? A pest is an organism that comes into conflict with humans. Nuisance Medical Agricultural Structural Turf Forest Objectives Pest management is a global problem. Provide your informed opinion on how we can most safely manage pests. What advice on pest management would you giveto farmers, to scientists, and to your friends and family? Describe, with examples, five ways we can control pests without insecticides. Outline the philosophy of IPM How do we know when to start taking action against a pest? Economic Injury Level The pest density at which the loss caused by the pest equals in value the cost of available control measures Basically, when it starts costing more to let the pest eat your crop than it costs to kill the pest. 1

2 How do we know when to start taking action against a pest? Insecticides Effective and cheap after World War II From 1950 to 1985 Insecticide use increased by 10x But, losses to insects have increased df from 7% to 13%. Why? The undesirable effects of insecticides 1. Pesticide resistance Pesticide resistance In any pest population there may be some pests with the genetic ability to survive a pesticide application Year 1 Mutation Selection event Pesticide application Adaptation Fitness Evolution A number of the offspring of the survivors inherit the resistance allele. These resistant pests survive the next spray. Year 2 Pesticide Resistance Resistance to Pesticides st species Number of resistant pes 2

3 The undesirable effects of insecticides 1. Pesticide resistance 2. Destruction of non target organisms 3. Pest resurgence (from 1 & 2) The undesirable effects of insecticides 1. Pesticide resistance 2. Destruction of non target organisms 3. Pest resurgence (from 1 & 2) 4. Secondary pest outbreak (from 1 & 2) 5. Adverse environmental effects The undesirable effects of insecticides 1. Pesticide resistance 2. Destruction of non target organisms 3. Pest resurgence (from 1 & 2) 4. Secondary pest outbreak (from 1 & 2) 5. Adverse environmental effects 6. Dangers to human health Botanical Controls: Insecticides Alkaloids including modified nicotine (neonicotinoids) Rotenone from roots of beans Pyrethrins/oids from flowers (Chrysanthemum) Neem from the neem tree Safest for mammals and birds But, these can still be dangerous! 3

4 Chemical Controls: Insecticides Chemical Classes Chlorinated hydrocarbons DDT dichlorodiphenyltrichloroethane Organophosphates Malathion Irreversibly inactivates acetylcholinesterase tlhli t Carbamates Reversibly inactivates acetylcholinesterase Pyrethrins/oids Binds to Na+ channels causing paralysis Neonicotinoids Bind to postsynaptic nicotinic acetylcholine receptor Always buy the least toxic pesticide possible! Check out UF information: 1. Mechanical/Physical Methods Just keep them away! Block them. 2. Cultural/Environmental Controls The ways in which you farm 3. Biological Control Find something that likes to eat them. 4. Parapheromones Attract them in with irresistible odors. 5. Genetic Control Zap them with radiation. Transgenic crops Mechanical/Physical Control Mechanical/Physical Methods Cultural/Environmental Controls Biological Control Parapheromones Genetic Control Cultural/Environmental Controls Sanitation Removal of waste residues Efficient storage Removal of alternativehosts Soil & Water Management Proper fertilization Drip/flood irrigation 4

5 Cultural/Environmental Controls Space/Time Disruption Crop rotation Crop spacing Crop/pest synchrony Trap cropping Intercropping Cultural/Environmental Controls Space/Time Disruption Crop rotation Crop spacing Crop/pest synchrony Trap cropping Intercropping Mechanical/Physical Methods Cultural/Environmental Controls Biological Control Parapheromones Genetic Control Biological Control Use natural enemies! Predators, parasitoids, parasites, microbes Biological Control Classical importation and release of natural enemies against exotic pests. Augmentation periodic release of existing natural enemies Conservation protect and enhance natural enemies (selective insecticide, timing applications) Mechanical/Physical Methods Cultural/Environmental Controls Biological Control Parapheromones Genetic Control 5

6 Parapheromones (remember this? From sensory systems lecture) Ceratitis capitata Mechanical/Physical Methods Cultural/Environmental Controls Biological Control Parapheromones Genetic Control Genetic Control Sterile Insect Technique New World Screwworm Cochliomyia hominivorax Genetic Control Transgenic Crops Bacillus thuringiensis (Bt) bacterium δ endotoxins cotton, corn, etc. Bt and genetic engineering Bt cotton and corn have been planted on a cumulative 200million ha worldwide since their commercialization in 1996 Bt and genetic engineering Concerns Genes from the modified plants may transfer to other plant varieties or species i l b d Transgenic plants may become new weeds Non target organisms, such as beneficial insects, may be harmed Bt resistance will evolve, just as pesticide resistance evolves. It is only a matter of time. 6

7 Who works in pest management? Growers Extension agents Chemists Geneticists Plant breeders Plant Pathologists Entomologists Microbiologists Principles of Integrated Pest Management 1. Accept some level of pests we just aren t going to be able to get rid of them all! 2. Limit i economic damage to the crop 3. Protect non target organisms, the environment, and human health Pesticides can still be used, but usually at a lower level What control measures are included in IPM? 1. Insecticides 2. Plant resistance improvement 3. Mechanical/Physical Methods 4. Cultural/Environmental Controls 5. Biological Control 6. Parapheromones 7. Genetic Control Pesticides can still be used, but usually at a lower level Pedigo (2002) Entomology and Pest Management True IPM is only being used on 10% of U.S. crops Why? 1. Need to have lots of data on insect pests and natural enemies. Who will finance the research? 2. Insecticides are promoted by companies and appear to be simpler to use than IPM 3. Training farmers who will finance the training? Who is responsible for safe pest management? Growers Extension agents Chemists Geneticists Plant breeders Plant Pathologists Entomologists Microbiologists You 7

8 What do you think? Should we get used to having insects in our food? Insect damage? How much chemical risk is worth it for us or for our environment? Are organic fruits, vegetables, and meats worth the extra effort and price? 8