Ipm
Provide a definition of a weed
A plant in the wrong place, unwanted and competing with profitable crops.
How did the invention of synthetic organic pesticides during World War 2 change pest management?
*Synthetic chemical insecticides invented in 1940's Organochlorides (DDT) Organophosphates (parathion, malathion, diazinon) *Organochlorides and phosphates were: Cheap Toxic to insects in small quantities Relatively non-toxic to humans *Used during WWII to stop insect vectored disease *Transitioned to agricultural and residential use after the war
List a few examples of the possible damages of a pesticide application that a PCA is supposed to list.
Harmful to a beneficial insect or amimal
How did the scientific awakening during the renaissance change pest management?
1600's the microscope is invented Discover that disease is caused by microbes Able to identify small insects and mites 1668 Francesco Redi proves maggots come from eggs, Not spontaneous generation 1735 Carl Linnaeus invents systematics 1st time weeds & insects identified with high accuracy
Know the comparative generation time of the major pest categories
A generation is the amount of time needed for an organism to pass from birth to active reproduction May vary widely under poor environmental conditions Pathogens and weeds tend to be variable Insects and vertebrates are consistent For pests with fast generations, it is best to manage the inoculum rather than the pest itself Short generations ≠ multiple generation per growing Most pests are specialists: Host plant Developmental stage Environmental conditions Vector relationships
What does it mean that a pest is a human construct?
A pest is any organism that negatively influences the activities and desires of humans Damage crops, Spread disease, Eat stored products, Damage structures
Be familiar with common symptoms of nematode infestations
Above ground: stunting, delayed maturity, chlorosis, and leaf drop Patches of field that fail to establish Below ground: galls, lesions, stunting, swollen knobby roots
List the 6 ways agroecosystems differ from naturally occurring ecosystems. Describe why these differences make them more prone to pest outbreaks.
Agroecosystems differ from natural ecosystems: 1. Lack of continuity - i.e. they can change rapidly 2. Dominated by human-selected plants - many non-native 3. Less species diversity, less genetic complexity, shorter food web 4. Uniform vegetative structure - life stages occur at the same time 5. Abiotic inputs typically added - water, nutrients, etc. 6. Frequent outbreaks of pests - weeds, insects, diseases
What is an externality? Describe some of the externalities associated with pesticide overuse.
An externality is a side effect of a commercial activity that affects other parties without this being reflected in the cost of the goods Positive externalities Ex: Honey bees pollinate cotton, producing honey for beekeepers Beekeepers benefit from the honey No cost to the cotton producer or consumer Negative externalities Ex: CO2 from burning fossil fuels raises global temperatures People suffer increased droughts, floods and sea levels Cost of flooding/drought isn't reflected in the cost of gasoline/oil/diesel/coal
Compare and contrast compatible and complementary controls. Be able to tell whether an integrated technique is compatible/complementary.
Compatible - can exist together without conflict Complementary - combining to enhance or emphasize the qualities of each other Compatible Control Incompatible: Broad spectrum insecticides and natural biological control of insects Compatible: Resistant crop varieties and tillage Complementary control Non-complementary: Mowing weeds and mating disruption of moths Complementary: Drip irrigation and phytophthera-resistant rootstocks
Describe the general life cycle of a weed, and distinguish between annuals, perennials, and biennials
Annual weeds are weeds that complete their life cycle within a single growing season Must germinate from seeds every year Summer annuals germinate in spring, and set seed from late summer through the early fall Winter annuals germinate in early fall, and set seed in late spring Biennial weeds require two growing seasons to complete a life cycle Perennial weeds survive multiple seasons and flower repeatedly
Be familiar with the EIL equation: EIL= C/(V*I*D*K)
C = cost of management per unit area (ex: $/acre) V = Market value per unit of product (ex: $/ton) I = Injury per pest within a certain area (ex: chewed leaves/insect/plant) The amount of physical damage caused by a single pest D = Damage per unit area per injured unit (ex: (tons/acre)/chewed leaf) The amount of economic loss caused by an injury K = proportion of damage which can be avoided with treatment (ex: 70%)
Compare and contrast the roles that PCA's, DPR, and the UC Statewide IPM program play in performing IPM in California.
CDPR: A dept. within the California Environmental Protection Agency Pesticide evaluation and registration Environmental monitoring for agricultural chemicals Enforcement of pesticide laws/regulations Residue testing of fresh produce Testing and licensure of commercial applicators, dealers, and PCAs Encouraging development of least-toxic pest management practices Chief administrators of pest management techniques Create incentives and grants for IPM Determine materials on the PCA exams UC Statewide IPM Program: 1979 - State funds UC Cooperative Extension to start a Statewide IPM program that would: increase the predictability and effectiveness of pest control techniques develop pest control programs that are economically, environmentally, and socially acceptable increase the utilization of natural pest controls prolong the useful life of acceptable pesticides by minimizing the development of pesticide resistance Basically the research wing of California IPM Develops new techniques and educate growers/PCAs on them
What does CEQA stand for, and why does it have such a significant impact on pest management in the state of California? Example: What is an Environmental Impact Reports (EIR), and why are they a challenge to applying pesticides?
California Environmental Quality Act (CEQA) Legal procedure to ensure environmental protection in CA Mandates all projects likely to have a major environmental impact (private or public) must: Provide notification of the project to the state government Have the project undergo a rigorous environmental impact review process The project may be rejected if less damaging alternatives are available Pesticide use count as an action likely to have a major impact on the environment
What is the importance of a biological pool? How do abiotic compounds become biologically available (enter the pool)?
Chemicals held in inorganic reservoirs and are converted to biologically available forms by certain organisms: Respiration Photosynthesis Decomposition Nitrogen fixation Absorption Broadly available once in the organic pool
Compare and contrast density dependent with density independent factors effecting population growth. Be able to distinguish between the two.
Density Independent factors affect populations regardless of organisms population density Kill the same percentage of pest whether population density is high or low Tend to be natural disturbances (fire, drought, flood, etc.) Density Dependent factors have a different affect on populations when they are at high density compared with when they are low Tend to kill a higher percentage of individuals when population densities are high, vs when they are low Often biological forces (competition, predation, disease, etc.)
Describe the types of damage caused by vertebrate pests
Direct damage to crops - Feeding on leaves, stems, roots, and fruits Indirect damage Chew through irrigation equipment Burrows harm livestock and employees Nesting in equipment Burrowing in irrigation canals Consumption of harvested products
Be able to describe the disease cycle, and distinguish between inoculum and infection
Disease cycle - series of events required for successful infection of a plant Inoculation is when the pathogen physically contacts the host plant Infection when the pathogen invades the host plant's tissue and initiates a parasitic relationship
Why is IPM considered a form of applied ecology?
Ecology - The study of relations of organisms with one another and their non-living physical surroundings How organisms interact with one another and the environment IPM is applied ecology Understanding a pest's lifecycle and natural interactions in order to: Reduce the environmental resources that help pests thrive Identify and exploit weaknesses in the pest's lifecycle
Describe the relationship between economic injury level and treatment thresholds
Economic Injury Level (EIL) - the smallest number of pests that will cause economic losses equal to the pest management cost Population where yield or quality loss costs the same as treatment Economic thresholds (ET, Action or Treatment threshold) the number of pests that trigger a management action Purposefully set at smaller value than the EIL
What is IPM Describe the major stakeholders of pesticide use, and what their interests are
Farmers - Inexpensive, easy, profitable, effective, low-risk, targeted Pest Control Industry - Monitoring, Chemicals, "Monetizable", Diverse tools, adaptable Consumers - Affordable, Effective, Safe Environment - Safety, Sustainable
Know the comparative fertility and fecundity of the major pest categories
Fecundity is an organism's potential reproductive capacity Measured in total gametes (eggs or sperm) produced per individual Fertility is the actual number of viable offspring produced per individual adult
Compare and contrast habitats and ecological niches. Describe how knowing a pest's ecological niche can provide us with control options.
Habitat - environment an individual or population lives in Includes abiotic environment and biotic populations Ecological Niche - all the components of the habitat an organism interacts with: 1. The organism's role in the community In terms of what it eats, and what eats it, how it reproduces, ecosystem services it provides, etc... 2. The mixture of conditions and resources requires to sustain the organism within the habitat
Differentiate fungi, bacteria, and viruses
Fungi are non-chlorophylic eukaryotes that obtain nutrients from living or dead hosts Bacteria are single-celled prokaryotic microorganisms Viruses - simple obligate pathogens that reproduce inside the cells of their hosts
Compare and contrast gaseous and sedimentary biogeochemical cycles.
Gaseous Cycles: Atmosphere is largest reservoir Includes: Oxygen, Carbon, & Nitrogen Sedimentary Cycles: Earth is largest reservoir Includes: Phosphorus & Sulfur
Describe what a control action guideline is, what kind of guidelines are commonly used for management of weeds, pathogens and arthropods?
Guidelines based on timing pest control to when it would be most effective Pathogens - guidelines based on weather data Grape Powdery Mildew model accounts for humidity and temperature Weeds - focus on the conduciveness of field-to-seed germination Apply pre-emergents based on soil moisture and temperature Apply post-emergents based on counts and development
Be able to describe the 4 levels of ecological organization we focused in on class (individual, population, community, & ecosystem), and how they interact & differ from one another.
Individual Base unit, source of diversity Populations Interaction of individuals of the same species Community Interactions between all populations of all species Ecosystem Includes interactions with the abiotic environment Biosphere All life on Earth (a bit big for practical applied IPM)
Why do insect populations require more regular monitoring than do weeds and pathogens?
Insects capable of directed dispersal under their own power Wings and small size allow log distance migration Must be mindful of surrounding habitat when monitoring arthropods
Be able to differentiate mites and insects
Insects: Three distinct body sections (Head, Thorax, Abdomen) Three pairs of legs Two pairs of wings One pair of antennae Complex external mouthparts Mites: Four pairs of legs Single body section Piercing sucking mouthparts that protrude from the front of the head Damage - removal of cell contents from leaves and fruits
Be able to describe how energy flows through an ecosystem via its trophic structure. Describe the trophic levels and outline their connectivity via food chains/webs. Outline how the rule of 10% limits the complexity of ecosystems.
Interactions driven by energy flow Determines food availability and biochemical production Sunlight: the primary source of energy Plants primary producers, using photosynthesis as the principle source of: Biologically available energy Organic material Trophic structure - the partitioning of energy within an ecosystem between different trophic levels Rule of 10% - Only 10 % of energy is transferred at each step, limiting the number of trophic levels, 90% of energy is lost Usually limited to 4-5 levels
Describe how pests physically interact with one another.
Interactions due to physical contact between pests, or pests and the host plant Physical damage to host Most pathogens can't penetrate the plant cuticle Requires damage from animal pest Root-knot nematode damage allows fusarium infection in cotton Physical external transport Pathogens may be carried on the outside of other pests, transporting them to new habitats Ex: Dutch elm spores on elm bark beetles Ex: Mammals carrying seeds on their fur, nematodes on paws
Predict how changes in immigration, emigration, birth rate and death rate can change the growth rate of a population.
Internal factors Birth and death of members of the population External factors Dispersal - the movement of individuals or their offspring into or out of a population Immigration - Movement into a population Emigration - Movement out of a population Model population growth with a simple equation Nt+1 = Nte(births-deaths)t + (Immigrationt - Emigrationt) Nt+1= population at the next time interval (ex: next week) Nt= population at time t (ex: population today) e is the base of the natural log (2.718) Immigration = number of insects migrating into the field Emigration = number of insect migrating out of the field Populations can only grow under three scenarios: When birth rate exceeds death rate When immigration exceeds emigration Or a combination of the two
List the 3 major benefits of integrated control
It is difficult for pests to evolve resistance to integrated tactics Selects for more than one mortality factor Reduced risk of tactic failure If one tactic fails, others will continue to provide some control Reduces pesticide contamination Integrated tactics reduce reliance on chemical control Fewer pesticides applied
Explain what carrying capacity is and how it alters population growth.
K = Carrying Capacity Maximum population that can be supported in an environment due to limiting factors Also known as equilibrium population density Term used on PCA exam Carrying capacity is not fixed May vary as the environment changes Determined by: Food web interactions Predation Parasitism Competition Resource Limitations Climactic conditions
Distinguish between major, minor, occasional and secondary pests. Be able to identify one from another if given an example.
Major/Key pests - Occur routinely and typically influence crop yield Pests that always require control Minor Pests - Occur routinely, but only cause minor damage Climate conditions that sometimes cause outbreaks Secondary Pests - Can cause serious damage, but usually are adequately controlled by natural enemies. Occasional Pests - Pests that are not routinely present, but can occur as a problem from time to time Migratory insects
Give a very complete definition of IPM
Management of agricultural and horticultural pests that minimizes the use of chemicals and emphasizes natural and low-toxicity methods The coordinated use of pest and environmental information along with available pest control methods, including cultural, biological, genetic, and chemical methods, to prevent unacceptable levels of pest damage by the most economical means, and with the least possible hazard to people, property, and the environment
Describe the requirements that a person must pass to become a PCA.
Meet core education and/or apprenticeship standards OPTION 1 - Bachelor's Degree OPTION 2 - Get a PhD OPTION 3 - work experience + Course work 42 semester hours of required coursework 24 months of combined work experience Pass a series of exams Laws & Regulations & Principles of IPM (200 questions) At least one pest category exam (100 questions) Only allowed to recommend pesticides depending on which exam you passed.
Be able to identify complete and incomplete metamorphosis
Metamorphosis - dramatic physical transformation between the final immature stage and the adult stage Incomplete metamorphosis - adult resembles immature stages, but with wings and reproductive organs, no pupation step Complete metamorphosis - adult insect physically and behaviorally distinct from the immature stage, includes immobile pupation stage Larvae often worm-like
Differentiate the 3 major types of nematodes
Migratory ectoparasites - feed on the exterior of the plant, and move between hosts Ring and pin nematodes Migratory endoparasites - feed internally, and move between multiple hosts Lesion, and stem nematodes Sedentary endoparasites - feed internally, within a single host plant
Be able to describe the importance of monitoring in an IPM program.
Monitoring is any procedure used to measure over time the activities, growth, development, and abundance of organisms or the factors affecting them Population size/location/development for pests and biological control agents Weather Crop condition Used to inform IPM decision making 1. Reduces risk by providing site-specific data 2. Justify pest management decisions to the grower 3. Provides information on treatment effectiveness 4. Saves money by eliminating unnecessary control
Be able to distinguish between monocots and dicots
Monocots: Vertical growing habit Tall and thin Meristem below or at the soil line Growing point near the soil line Fibrous roots Dicots: Meristem above the soil line Flowers & Fruits Broad Leaves
In California you must have a PCA license to do what three things for a pest control technique or product used in agriculture?
Offer a recommendation on any agricultural use of a pest control product of technique Present yourself as an authority on any agricultural use of a pest control product Solicit service or sales for any agricultural use of pest control products
Be able to list and describe the five components found in EVERY IPM SYSTEM
Pest ID - IMP requires all pests to be accurately identified to the species level IPM emphasizes use of non-chemical approaches (biocontrol and cultural) Non-chemical tools target pest ecology and life cycle Differ significantly between pests Avoid pesticides when they aren't needed Often make decisions based on indirect evidence Pests are not always present when damage is discovered Field Monitoring - Fields must be regularly checked for factors that can be used to predict and evaluate potential pests Pests are not always present in fields Highly mobile pests may migrate into fields (insects, invertebrates) Pests are not always capable of damaging crops Fungal pathogens most damaging in humid warm weather Weed damage is associated with the location Allows PCAs to identify pest outbreaks or prevent outbreaks with preventative control Pest Monitoring Includes: Direct observation of pest presence/density (sweep, traps, weed walks) Indirect measure (damage, stand counts, symptoms) Measuring environmental factors that influence pest growth (crop phenology, weather, soil conditions, presence of species) Keep records of pests, weather, and management activities Helps identify patterns Provides support when making a recommendation Control Action Guidelines - any rules, principles, or tools that help us decide when it is appropriate to control a pest Tolerable injury level is the number of pests (or amount of pest damage) where the cost of damage caused by the pests is less than the cost to manage the pest Most pests don't cause serious yield or quality losses at low population densities We can tolerate pest populations provided they stay within the tolerable injury level Tolerable Injury Levels may vary drastically by pest species Ideally, Control Action Guidelines allow us to time our control applications to just before pest density passes the tolerance injury A Treatment Threshold is the density of pests ( or amount of pest damage) where applying control will provide an economic return. That is the number of pests where you are justified in applying a pesticide Apply control if pest density is above the treatment threshold Most used for easy-to-count pests such as insects and mites Some pests are not easily counted Prevention Preventive control takes place before the pest or its symptoms Curative control takes place after the pest is detected Preventive measures minimize pest growth, often negating the need for curative approaches Bush Early Girl tomatoes resistant to: Root-knot nematode, Vetricilium, Fusarium, Tomato spotted wilt, Tobacco mosaic virus Planting resistant tomatoes can completely remove the need for fungicide applications Integration Integration is the use of multiple compatible and complementary management tactics coordinated within a single pest management program Compatible - can exist together without conflict Complementary - combining to enhance or emphasize the qualities of each other Compatible Control Incompatible: Broad spectrum insecticides and natural biological control of insects Compatible: Resistant crop varieties and tillage Complementary control Non-complementary: Mowing weeds and mating disruption of moths Complementary: Drip irrigation and phytophthera-resistant rootstocks
Describe how a pest may effect other pests by modifying the environment.
Pest activity may alter the habitat, to make it more (or less) suitable to other pests Example, cutworms consuming plants opens the canopy Increases light - favoring weeds Raising temperature - favors insects/nematodes Reducing soil moisture - favors weeds
Describe how pest management is like insurance.
Pest control does not add value to crop Does not increase yield or improve quality Pest control protects existing yield Pest control protects from an uncertain threat Pests do not always damage crops The specific threats and types of pest vary year to year Pest control needs to be purchase before the damage occurs Estimate cost of damage Estimate cost of control Estimate amount of value protected Pay for control if protected value is greater than the cost of control
Describe how pests interact with one another during feeding.
Pest may feed on the same host and compete for resources Competition rarely reduces pest populations Usually, pests synergize to cause greater damage One weakens the plant making it more vulnerable to other pests Ex: Nematodes and fusarium in watermelon Fusarium alone: can't penetrate roots Nematodes alone: feed on seedlings but cause little harm Nematodes + Fusarium: Nematodes create holes in roots, fusarium infects the plant causing disease
Be able to describe the importance of phenology and climate monitoring for an IPM program. What are the advantages of climate monitoring over a calendar day system.
Phenology is the study of the timing of periodic events in an organisms life cycle When life cycle events occur Environment variables that are associated with them Temperature, day length, germination of host plants, and precipitation Phenology models predict pest emergence and outbreaks using environmental data and pest development patterns May be used to time pesticide applications Use of weather stations for IPM Weather stations are essential for: Calculating degree days and pathogen models Estimating moisture data Prevailing winds for pathogen dispersal
Know the four major challenges to synthetic pesticide use (resistance, resurgence, secondary pest outbreaks, and environmental contamination), and how they contributed to the founding of IPM.
Resistance - the decreased susceptibility of a pest population to a previously effective pesticide Caused by natural selection favoring resistant individuals 1946 - DDT resistant houseflies detected 20 years later 224 resistant species 75% of CA Ag pests Pest resurgence - the tendency of pest populations to rapidly rebound after a pesticide application often due to the release from predator pressure Insecticides kills most pests and natural enemies Pest populations freed from biocontrol rebound quickly Secondary pest outbreaks - a previously pest species becomes a primary pest after pesticide application Often pesticides remove the natural enemies keeping pests in check Ex: Cottony Cushion Scale DDT used to manage pests in citrus Vedalia beetle provided control Beetle is susceptible to DDT CCS became a pest again
Be able to explain why prevention is economically advantageous compared to curative management
Preventative control prevents pest outbreaks which can significantly cause yield loss or costs in controlling the outbreak.
Compare and contrast preventive and curative control
Preventive control takes place before the pest or its symptoms Curative control takes place after the pest is detected Preventive measures minimize pest growth, often negating the need for curative approaches
Be able to list and describe the primary services that PCA's offer in California.
Primarily, a PCA is a pest management expert Experienced in techniques & technologies Can identify, monitor, and model pest populations Aware of environmental and regulatory risks Familiar with the most effective pesticides Growers hire them to manage their crop's health including: Monitoring pest populations Providing written recommendations for control when warranted Submitting relevant paperwork to state regulators May provide advice on irrigation, fertility, cultural practices, etc. based on training If provided a CCA license
List the common traits of weedy plants
Produce large quantities of seeds Seeds adapted for dispersal Seeds adapted for long-term dormancy Vegetative reproductive structures allow short-distance spread Tend to sprout and grow early in the growing season
Be able to distinguish between the age structures of growing, stable, and shrinking populations
Proportion of individuals of different ages can indicate whether a population is expanding, declining, or stable Expanding: a large percentage of young individuals Declining: a large percentage of old individuals Stable: relatively even distribution of all ages Pests rarely attain stable populations
Explain what the risk equation is, and list practical steps we can take to reduce the risk posed by pesticides.
RISK = HAZARD x EXPOSURE Risk is the likelihood that harm will actually occur Hazard is the innate property of an object that makes it capable of causing harm Exposure is the extent to which a person is subjected to the hazard
List some of the benefits that IPM has had in California.
Reduction of pesticide use
What does FAC12003 mandate of PCAs?
Requires a written recommendation from a PCA for any application of a pesticide
Know how to use the sample size equation. Be able to calculate an ideal sampling size using it.
Sample size formulas - more complex, but accurate n - number of samples t - value from "student t" table (usually 2) s -standard deviation of the sample D - The percent error you will allow x - the mean (average) of the samples
Describe the difference between monitoring and sampling.
Sampling - the collection of measurements from a part of a population or features of an environment Observations of a subset of the entire population Used to extrapolate patterns for the whole population Sampling is the act of collecting a data point for monitoring Sweeping insects Scouting signs of disease Reading a weather report Collecting a soil sample for nematodes It is the backbone of IPM Garbage In = Garbage Out
When given a description of a field, pest, its distribution/density, ET, and EIL be able to design a monitoring program including: sampling universe, sampling strategy, sampling unit, ways to increase sampling efficiency, optimal sampling pattern and potential treatment.
Sampling Patterns - the path followed when collecting samples should be representative of the entire field Different patterns are used to achieve different objectives BUT - All must be unbiased Random Sampling - where every sample unit has an equal chance of selection An unbiased representation of the population The most common sampling type Surprisingly difficulty to be random Throw a ball or ring Use a random number of steps between samples Follow different paths Stratified sampling - divide habitat into subunits that vary in some character, then sample the subunits independently Good for universes with diverse habitats Reduces variability among samples, increasing accuracy Systematic Sampling - sample regularly from randomly selected starting point Ex: every 50th plant, every 10 feet, every 5th time around, etc. Should only be used in homogenous fields When habitat variability does not need to be accounted for Economic Decision Making
What is sampling efficiency? What are some tools used to increase sampling efficiency?
Sampling efficiency Accuracy - how closely a sampling technique matches the true population mean Cost - The amount of time, effort, money required to collect samples Low sampling efficiency: When the cost is high relative to accuracy Bad... High sampling efficiency: When cost is low and accuracy is high The ideal Increase efficiency by: Reduce the number of samples Increasing the precision of our samples
Describe how environmental pressure can shift the distribution of genotypes in a population, and how this can impact the population's phenotype. How does this relate to pesticide resistance?
Some phenotypes increase an individual's fitness - the ability of an organisms to pass on its genes to the next generation (long life & reproductive success) Genotypes that increase fitness are more likely to be passed to the next generation Genotypes poorly suited to the ecosystem reduce fitness and become less common Natural selection is the differential survival and reproduction of individuals due to phenotypes Genotype or phenotype fitness depends on the environment Fitness will change if the conditions that favor it change Rare traits can become common if selection pressure is high enough Pressure shifts such as excessive applications of the same pesticides could result in the ability of an organisms to acquire resistance genes and pass it on th their offspring.
Explain what it means that a PCA is liable for their written recommendations? How can IPM be used to reduce the dangers of liability?
The California Food and Agriculture Code 12003 requires a written recommendation from a PCA for any application of a pesticide Without this written recommendation a farmer cannot legally apply a pesticide Pesticide retailers cannot sell or provide pesticides either PCAs are considered experts in their field and assume legal responsibility for their recommendations If pest management practices fail or spray damage a crop, they may be liable PCAs must keep all parties informed of the risks and benefits of recommendations and keep good written records to limit liability Carry liability insurance - like malpractice coverage
What was the pesticide treadmill? How do resistance, resurgence and secondary pest outbreaks contribute to its effect?
The Pesticide Treadmill describes the situation where pesticide use prevents natural pest control, requiring repeated applications of pesticides at higher doses to keep pests in check Feedback loop where pesticide application create more resistance requiring more pesticide applications New pesticides needed to control pests Goes on forever until either: Resistance proof pesticide is invented Fully resistant insects emerge
Compare and contrast sampling accuracy and precision. Describe ways that you can increase the accuracy and precision of sampling techniques.
The purpose of sampling is to estimate the total pest population of a field Assumption: The sample mean is reflective of the true pest population Accuracy - how close a sample mean is to the true mean How well do our samples represent the population Precision - the variability among samples How close measurements are to one another (standard deviation)
What is the role of a vector in virus life cycles?
Vector - an organism that transmits a disease
Be able to explain why weeds are the keystone pest in most agricultural systems.
Weeds serve as alternative host to insects, vertebrates, nematodes, and pathogens Allow consumer pests to survive when the crop is unavailable
Compare and contrast R-strategists and K-strategists. Specifically, how do the two adaptive strategies differ in how they handle competition, habitat disruption, reproduction, and lifespan. Be able to identify a pest's survival strategy based on its ecology and life-cycle.
r strategists - competitive in broad empty niches High rate of reproduction Efficient host finding Rapid colonization "Short Run" Species Well suited for high disturbance systems Systems with little competition Most pests: aphids, mites, most common weeds k strategists - Competitive in narrow well-developed niches Slower reproduction Longer life Few offspring with more parental care "Long Run" Species Well suited for complex ecosystems With strong competition Relatively few pests: woody weeds, wood boring beetles Biological control: lady beetles, lacewings, symbiotic fungi
Know the 4 factors that must be present for an organism to be a pest (Pest, Environment, Crop, & Time).
The pest must be present in a destructive life stage The environment must meet the needs of the pest The crop must be susceptible to the pest and in a susceptible growth stage Enough time for pest populations to reach damaging levels