Pest managament

Question 1

Define Integrated Pest management

Answer 1

A pest control strategy that uses an array of complementary methods (mechanical devices, physical devices, genetic, biological, legal, cultural management, and chemical management) in three different strategies (prevention, observation, and intervention) to significantly reduce or eliminate the use of pesticides

Question 2

How is prevention used to construct an effective I program?

Answer 2

Stops pests from being introduced to a location

Regulations and quarantines are commonly used to prevent introduction

eradication is used to prevent the pest from remaining in the area if pest is already there.

Question 3

How is avoidance used to construct an effective IPM program?

Answer 3

Keeps a species population below levels where it would be a pest

Pest target is kept healthy so pest damage is below economic threshold

Pest target can be given increased pest resistance through breeding and genetic engineering

Natural enemies can be maintained or increased

Traps can be used to lower pest population

Barriers can be used to separate the pest from host

Question 4

How is monitoring used to construct an effective IPM program?

Answer 4

Characterized the presence/ absence of the pest and, if present the fluctuations in the pest populations

May include the degree/extent of pest damage to the host

Question 5

How is suppression used to construct an effective IPM program?

Answer 5

Used to reduce pest populations below the economic threshold of prevention and avoidance tactics fail

Chemical, biological, cultural and other tactics are used to minimize environmental impacts

Question 6

What are the steps of an IPM program?

Answer 6

Sampling and monitoring

Identification (kind, nature, and severity of pest damage or potential for damage)

Determining need for control (compare cost of treatment with economic benefit of treatment)

Evaluating control options

Implementation

Evaluation and record keeping

Question 7

How do pathogens, predators, and parasites affect insect pest population development?

Answer 7

Each can reduce pest populations

Pathogen causes a disease to occur in pest

Predators attack the pest and may use it as food

Parasites live on or in the pest and may use t as food

Question 8

How do host plants affect insect pest population development?

Answer 8

Presence of a host plant increases the possibility of increased pest populations

Question 9

How does the initial pest population affect insect pest population development?

Answer 9

The higher the initial pest population, the higher the potential for increased pest populations

Initial population of insects or insect density is modified by the spatial distribution of the insects (dispersion), their birth rate (Natality), the pattern of insect growth, and age of the insect population

May or may not lead to higher insect populations

Question 10

How does temperature affect insect pest population development?

Answer 10

Pests grow and develop in response to thermal inputs

Each organism has a min, max, and optimum temp for growth and development which can change during a life cycle

Often insects grow and develop in response to degree days or the accumulation of heat above a threshold value

Question 11

How does soil characteristics and conditions affect insect pest population development?

Answer 11

Soil physical properties like moisture, temp, and aeration can be important in the growth and development of some insect populations

Question 12

How does wind affect insect pest population development?

Answer 12

Wind transports insects to new locations for infestation

Wind damage to immature plants can be misinterpreted as insect damage

Question 13

How does developmental time and seasonal period of activity of an insect influence their ability to cause damage?

Answer 13

They are related to factors like temp, light, and food supply.

When developmental time and period of activity of the insect coincide with the growth of a host crop, damage may occur

Question 14

How does the reproduction rate and number of generations per season of an insect influence their ability to cause damage?

Answer 14

The number of eggs (rate) and the number of generations per season combine to improve the survivability of the insect

Some insects produce large numbers of eggs, others produce many generations per season

Question 15

How does over wintering and over summering strategies of an insect influence their ability to cause damage?

Answer 15

These help to assure that the insect will survive and be competitive

Question 16

How do feeding habits of an insect influence their ability to cause damage?

Answer 16

Chewing insects remove plant parts where metabolic activities occur or fruiting structures of plants

Piercing-sucking insects remove the internal fluids of the plant, interfering with metabolic activity

Insect activity can also damage plants by vectoring disease

Question 17

What are the 3 types of metamorphosis?

Answer 17

None/without/simple: egg, young adult with young looking like adult but smaller and feeding on same food source as adult

Gradual/simple: egg, naiad, adult. Naiad look generally like adult but without wings and external genital appendages. Each time naiad goes through feeding stage (instant) followed by a molt it looks more like the adult. All immatures are aquatic and have gills with different food sources for adults and immatures

Complete/complex: egg, larva, pups, adult. Larvae go through series of growth stages and molts but remain worm-like. Food source may or may not be the same. Many species undergo complete metamorphosis

Question 18

What are the three keys to maximizing disease development and damage to crop?

Answer 18

Environment must be optimum for pathogen growth

Host must be highly susceptible to the pathogen

Pathogen must be abundant , active, and virulent

Question 19

How do fungi survive between crops, move field to field, and infect plants?

Answer 19

Survival: mycelia, spores, sclerotia in infect plants, debris, soil, insects

Movement: dispersal by wind, water, insects, animals, humans

Infection:

Grow through cell (intracellular mycelium) or between cells (intercellular mycelium)

Question 20

How do bacteria survive between crops, move field to field, and infect plants?

Answer 20

Survival: in infected plants, debris, soil, insects

Movement: dispersal by water, insects, animals, humans

Infection: invade plant tissue through the cells (intracellular) or between cells (intercellular)

Question 21

How do viruses survive between crops, move field to field, and infect plants?

Answer 21

Survival: in living tissue, insects, nematodes

Movement: dispersal by insects, humans

Infection: invade plant tissue through the cells (intracellular)

Question 22

How do nematodes survive between crops, move field to field, and infect plants?

Answer 22

Survival: eggs in soil, eggs and nematodes in roots, some larva and adults in seeds or bulbs

Movement: dispersal by water, animals, humans

Infection: invade plant tissue through the cells (intracellular) or between the cells (intercellular)

Question 23

How does weed growth rate affect the competitive ability of weed populations?

Answer 23

High growth rate makes it more possible for the weed to intercept light and shade the crop, and to have a large root system which will extract water and nutrients needed by the crops

Early emergence also increases competitiveness

Question 24

How does weed seed production affect the competitive ability of weed populations?

Answer 24

High seed production increases the likelihood that the weed will remain at competitive populations in the field

Question 25

How does weed seed dormancy affect the competitive ability of weed populations?

Answer 25

Seed dormancy will ensure the weed will survive in the field for years allowing it to reappear at competitive levels when the dormancy is broken

Question 26

How does weed reproduction method affect the competitive ability of weed populations?

Answer 26

Weeds reproduce by seed and vegetative growth Seed variability, seed dormancy, and seed numbers are important for weeds that produce seeds Vegetative reproduction is common for perennial weeds where they reproduce from stolons, rhizomes, bulbs, aerial bulblets, comes, tubers, or tap roots (these asexual reproductive parts are hard to control culturally)

Question 27

How does weed life cycle affect the competitive ability of weed populations?

Answer 27

Weeds that germinate before crop plants germinate and grow rapidly while the crop is small are more competitive. Weed survival depends on the ability of the weed to complete its life cycle, including production of viable seed that remain viable in the soil for extended periods, and/or maintenance of vegetative reproductive structures

Question 28

What are advantages/disadvantages to direct observation?

Answer 28

Advantage: no equipment needed, good for small plants Disadvantage: careful observation a must, more difficult in dense plant stands

Question 29

What are advantages/disadvantages to sweep net and drop cloths?

Answer 29

Advantage: inexpensive, can be used to sample many pests Disadvantage: sweeping efficiency varies from person to person, insects per sweep is not a direct measure of population per area

Question 30

What are advantages/disadvantages to insect traps?

Answer 30

Advantage: trap specific insects of interest Disadvantage: only trap insects that will move to the trap

Question 31

How are heat units calculated?

Answer 31

Air temp is used to calculate heat units Heat units that accumulate in a day equal the average temp that day minus some base temp (unless there is a temp max) If there is a temp max, the heat units for that day would be the temp max minus the base temp

Question 32

How are weed samples obtained, prepared, and shipped for evaluation?

Answer 32

Collect the whole weed, including the root system Blog any excess moisture off the weed, place it in a plastic bag, seal the bag, and refrigerate. Send weed sample to lab ASAP

Question 33

How are insect samples obtained, prepared, and shipped for evaluation?

Answer 33

Collect the insect, place it in a vial with rubbing alcohol, and tightly seal vial. Ship to lab for identification

Question 34

How are diseased plants samples obtained, prepared, and shipped for evaluation?

Answer 34

If possible, collect the whole plant, including root system. If it’s not possible to collect the whole plant, collect affected part and put in plastic bag. Shake soil from roots, but do not wash roots. Enclose roots in plastic bag and then enclose the whole plant in a second plastic bag. Do not add moisture, refrigerate prior to shipment. Ship ASAP

Question 35

How are soil samples for nematode analysis obtained, prepared, and shipped for evaluation?

Answer 35

Collect soil samples similar to routine soil samples for soil fertility testing. There is considerable spatial variability in nematode populations, so fields should not be too large (<50 acres) for a sample. There are specific, optimum dates for sample collection for some nematodes to improve the interpretation of potential damage Soil samples should be placed in plastic bags and sealed. Soil should not be dried out and should be protected from sun, freezing, and heat. It is best to store sample on ice (refrigerate) and ship to lab within the next day or so.

Question 36

What factors can help identify a pest?

Answer 36

Crop grown Time of year Symptoms/ pattern of damage Distinguishing characteristics of pest Distribution in field

Question 37

What pest characteristics can be used to identify pests and insects?

Answer 37

Type and number of legs: mites vary (0-8), insects have 6. Legs can be segmented Type of mouth parts: piercing-sucking features or biting/chewing features Wing characteristics Life cycle

Question 38

What are cotyledon features to evaluate when differentiating weeds

Answer 38

Above ground vs below ground cotyledons Presence/absence, number, and orientation of lobes Length and width; length vs width Thickness Margins parallel or other Venation Pubescence Color Shape Odor

Question 39

How are arrangement, shape, and vein pattern on leaves evaluated to differentiate weeds?

Answer 39

Leaf arrangement (attachment to stalk): alternate, opposite, whorled Leaf morphology evaluation includes Types: simple, compound (trifoliate, dissected, leaflet numbers, and types) Margins (entire, toothed, loved, undulated, hairy) Shapes (length, width, length vs width, linear, elliptic, oval) Surface (upper, lower, smooth, hairy, projections, waxy, granules, glands) Hair (short, stiff, long, soft, shaggy, appeased, position on leaf, star shaped, unbranched, dense) Vein and mid vein characteristics Color Odor Juice when crushed/broken

Question 40

How are ligules and audibles evaluated to differentiate weeds?

Answer 40

Aruicles: Presence/absence ligule: Presence/absence Membranaceous Shape (obtuse, truncate, acute) Fringe of hairs Margins (ciliate, notched/toothed, smooth

Question 41

What are the different stem shapes?

Answer 41

Tuber: enlarged underground stem that has nodes Rhizome: underground stem that can have buds that sprout forming new shoots Stolen: above ground stem with buds that sprout forming new shoots Bulb: underground stem with fleshy leaves that store food Corm: fleshy underground stem with papery leaves Grass stems are flattened or round Broadleaf stems are erect, twisted, or growing along the ground

Question 42

What are the different types of root systems?

Answer 42

Tap root: main root enlarging and growing downward Fibrous roots: thin, thread-like roots, usually without a primary root present Adventitious root: root growing from something else other than root tissue (stem, etc) Tuberous root: root enlarged for storage of food reserves Aerial root: adventitious root produced above ground, often for climbing

Question 43

What non-pest factors can cause plant damage?

Answer 43

Wind lodging: plant parts are rubbed together or broken off by wind Sandblasting: sand size particles carried by wind that damages plants Temp extremes: high temps cause enzyme systems to alter or inactivate. Low temps cause ice to form between plant cells and then within cells disrupting them Rain, hail, and ice: snow hail and ice can break plant parts due to weight or impact on plant branches or growing points. Rain can increase the possibility of lodging Moisture extremes Sunlight Pesticides phytotoxicity: pesticides can damage nontarget crops/plants Nutrient deficiency/toxicity Soil compaction Lightning Mechanical/ animal

Question 44

What are advantages/limitations to using hand lens for diagnosis?

Answer 44

Advantage: easy to use, several samples can be viewed Limitation: must record observations in data book, requires clear wording

Question 45

What are advantages/limitations to using digital camera as a diagnostic tool?

Answer 45

Advantage: easy to use, several samples can be recorded, record of specimen for future use Limitation: lens may not be correct for good image, may be difficult to acquire images from some perspectives, need correct lighting

Question 46

What are advantages/limitations to using picture references as a diagnostic tool?

Answer 46

Advantage: easy to use Limitation: does not show variability in pest characteristics

Question 47

What are advantages/limitations to using dichotomous key as a diagnostic tool?

Answer 47

Advantage: logical process leading to a result Limitation: may lead to erroneous conclusions, need several specimens, verification using another method is recommended

Question 48

Distinguish action threshold from economic injury level

Answer 48

Action threshold (AT) is that pest population and/or associated injury when pest control will prevent the economic injury level (EIL) from being reached. EIL: the point where pest management costs equal loss in income due to the damage from the pest Above EIL, income loss will occur unless the pest is controlled

Question 49

How is economic injury level calculated?

Answer 49

EIL= C/ (V*I*D) C: cost of pest management alternative $/acre V: value of the part of crop sold $/lb I: injury amount % loss/pest/acre D: damage per injury amount lbs/acre/% loss

Question 50

When is treatment cost effective?

Answer 50

When EIL<1 C< V*I*D Cost of treatment is less than income lost from pest damage

Question 51

What information can be used to make the best pest management decisions?

Answer 51

Current crop pest data from monitoring and scouting Pest history Pesticide history Cropping history Fertility level Soil, weather, and crop conditions Future cropping plans Crop biotech traits Refuge locations

Question 52

Distinguish genetic resistance and transgenic resistance

Answer 52

Genetic resistance is created through breeding crops to develop crops which are resistant to a pest (plant can exclude or overcome pest) Transgenic resistance of a crop to a pest is resistance obtained from the genetic material of another species of plant/animal

Question 53

How do Bt modified crops affect pest management?

Answer 53

Can be used in place of insecticides which reduces insecticide use in the crop. Refuge areas of the same crop not containing Bt must be planted nearby to reduce genetic alteration in the target insects that would make them tolerant of Bt toxin

Question 54

How does glyphosate resistance affect pest management?

Answer 54

A crop with glyphosate resistance can be sprayed with glyphosate without being damaged.

Question 55

How does glufosinate resistance affect pest management?

Answer 55

Glufosinate herbicide can be used on glufosinate resistant crops without being damaged.

Question 56

What are the advantages/ limitations to incorporating multiple traits into crops through transgenic techniques?

Answer 56

Advantages: - Chemical applications reduced/eliminated if genetically engineered crop controls pest - multiple pests can be controlled at the same time - fewer trips across the field with implements or aerial applications - eliminates environmental problems and pesticide carryover if pesticides are not used - less management required (fewer chemical applications) Limitations: - yield may be less - cost of seed and technology fee - pests may develop resistance

Question 57

Describe the concept of critical weed free period

Answer 57

The time during the growing season when the crop must be kept free of weeds. If the crop is not weed free during this period, yield and/or crop quality will decrease. The time during the growing season is often defined in terms of crop development

Question 58

Identify biological control agents

Answer 58

Lacewings Ground beetles Lady bugs Minute pirate bugs Damsel bug Parasitic wasp Predatory mites Spiders Syriphidfly larvae

Question 59

What are the advantages/ limitations to using biological control agents in crop production?

Answer 59

Advantages: - used to control a specific pest or group of pests - agents that are not indigenous to the crop or location usually offer the best pest control Limitations: - lack of broad spectrum control - potential damage to non-target organisms - cost

Question 60

What is mode of action and how does it affect pesticide selection?

Answer 60

Mode of action: the way the pesticide kills/ damages pest Using the same mode of action repeatedly can lead to pest resistance to pesticides and lack of efficacy. Varying mode of action reduces potential for pest resistance.

Question 61

Distinguish contact and systematic pesticides

Answer 61

Contact pesticides exert their pesticidal action at the point of contact with the plant or pest Systematic pesticides move in the plant to the site of pesticidal action

Question 62

What factors increase the risk of crop injury from pesticides

Answer 62

Application near a sensitive crop Improper aerial application Wind High temp which increases volatilization Use of small droplets, high pressure, higher boom height, lower spray viscosity

Question 63

What are advantages/ limitations to ground application methods?

Answer 63

Advantages: less drift, cost-effective for smaller areas Limitations: slow, timeliness, soil compaction, crop plant physical injury by equipment

Question 64

What are advantages/ limitations to aerial application methods?

Answer 64

Advantages: large area sprayed quickly, timeliness, use where ground rigs can’t go(wet areas, closed canopies) no physical damage to crop or soil Limitations: more drift, costly for small areas, increases public concern, weather

Question 65

What are the different mode of action groups and what plant injury symptoms do they cause?

Answer 65

Photosynthesis inhibitors: Contact burn of existing leaves, chlorosis of oldest leaf margins of seedlings if soil uptake Cell membrane disrupters: Contact burn of existing leaves, chlorosis of veins if soil uptake Growth regulators: Distorted growth of new leaves, callus growth on stem Pigment inhibitors: Bleaching (white) of existing leaves Seedling growth inhibitors: Clubbed root tips or leading out underground, wrapped leaves, buggy whipping Amino acid synthesis inhibitors: Chlorotic new growth to death depending on rate, white flash in corn Nitrogen metabolism inhibitors: Chlorosis of entire plant in 4-5 days Lipid synthesis inhibitors: Growing point rots, new leaves pull out easy, white flash in corn

Question 66

What insect stage is most sensitive to insecticides?

Answer 66

Early stages (larva, pupa), early vs late in stars eggs just before hatching

Question 67

Describe the types of insecticide activity

Answer 67

Contact: Enters the insect when insect comes in contact (touch, ingestion, inhalation) with chemical Stomach poisoning: Stomach poisons are ingested by insect Systemic: Absorbed by plant or animal which is then ingested by the insect Ovicidal: Kill insect eggs ``` Juvenile hormone (insect growth regulators): Kill pest when applied at the proper point in the metamorphosis ```

Question 68

How is pesticide dosage determined?

Answer 68

Determine rate: Correct amount of active ingredient (ai) to apply from the label by considering weeds present, soils, and other factors Determine Concentration: Actual amount of active ingredient in pesticide *make sure units (lbs ai/ac, kg ai/ha, oz ai/1000 ft2) are the same as for concentration and rate! Dosage= rate/concentration