Pest Management Exam 1

Most important plant pathogen

Fungi

Why are fungi so detrimental?

Form spores that penetrate plant surfaces and reproduce in many ways

First described pest management

Sumerian Farmers Almanac

Who discovered microbes?

Antonie Von Leeuwenhoek

Single celled, simple. Horizontal gene transfer. Binary fission

Bacteria

Microscopic roundworms with sexual and asexual reproduction

Nematodes

Not alive. Obligate intracellular parasites. Asexual reproduction. Need host cells. Can’t kill.

Virus

Salt water in the 1600s

First seed treatment

Mixture containing copper sulfate, lime, and water used to save grapes from downy mildew

Bordeaux mixture by Millardet

Copper widely used, antibiotics only in fruit orchards

Bacterial pathogen control

Inorganic, broad spectrum, high toxicity

Early chemical management

Dramatic yield increase, treated soil before planting, biocide, caused ozone hole

Soil fumigation

Categories of disease management

Quarantine, cultural, resistance, biological, chemical

1. Hard skeleton

2. Flight

3. Complete metamorphosis

Why insects are so successful

Parts of an insect

Head, thorax, abdomen

3 segments, first only has legs, second and third have wings and legs

Thorax

Reproductive, sensory, leglet appendages; viceral systems; digestive system; respiration; circulation

Abdomen

Do insects have lungs?

No, network of tubes and air sacs

Protects, stores waste, colorful, many layers

Exoskeleton

juvenile and adult look the same

Hemimetabolous

Larve, pupae, adult

Holometabolous

Who controlled the cottony cushion scale (parasitic fly) and grape phylloxera (grafting) in the US

CV Riley

Created land grant universities from native land

Morrill act 1862

Funded ag. experimental research stations

Hatch act

Heavy metals, pollutants, biological control, broad spectrum, DDT

War on pests (1800s-1900s)

Book by Rachel Carson about pesticides and DDT in the food chain

Silent spring

Mother of entomology who drew discovered metamorphosis

Maria Sibylla Merion

Drew engraving plates for textbooks, first female Cornell professor

Anna Comstock

Holistic approach, minimize impacts on environment, economic threshold

Integrated Pest Management (IPM)

Alteration of production practices (ex. trap copping, push/pull systems)

Cultural controls

Specialized equipment like barriers, trapping, physical removal

Mechanical controls

Use predators to manage population

Biological control

Insecticide to kill, repel, and control

Chemical control

Synthetically derived from chrysanthemum to destabilize neuron membranes. Low to moderate toxicity to non targets

Pyrethroids

Prevent termination of nerve impulse, carcinogenic, high toxicity

Organophosphates

Modeled after nicotine, blocks acetylcholine receptors, low toxicity to non targets, high toxicity to beneficial insects.

Neonicotinoids

Interfere with normal insect growth, prevents adult stage

Insect growth regulators

Dose where 50% of the pests die

LD₅₀

1. Tolerence to pest

2. Antibiosis

3. Antixenosis

4. HPR

Host plant resistance

Release a large amount of sterile males to tank population- SIT

Sterile insect technique

Yield needed to gain to make a management financially viable Gain= $ per acre/ $ per bushel

Gain threshold

Negative damage by pest

Injury

Plant response- manageable

Damage

Lowest level of injury damage manifests

Damage boundary

Where injury causes economically important damage

Economic injury

Lowest pest pop that will cause economic damage

EIL

What is C in EIL

Cost to manage

What is V in EIL

Value of crop

what is K in EIL

Percent of insects removed by control

What is YL in EIL

Yield loss due to pests

How to calculate yield loss?

injury per insect / density

What is K in graphs?

Carrying capacity

Unrestricted population will grow

Exponentially

EIL is

#insect or damage / area

1. Host

2. Pathogen

3. Environment

Factors of plant disease triangle

#hrs with RH >90% and average temp

Daily Infection Value

Best in developed countries with ag/bio effort and communication

Forecasting

more than 1 disease cycle / season, rate increases exponentially

polycyclic

1 disease cycle / season- rate increase at start and plateau

monocyclic

Most predictive of yield production, how diseases change over time

Area Under Disease Progress Curve

Produced by spores and can cause liver cancer in humans

Mycotoxins

up to 40% of food loss

Post harvest loss

loss at retail/consumer level

developed countries

processing issues, harvesting techniques, lack of transport

developing countries

Population below EIL where control will prevent population from reaching EIL.

Economic threshold

Nominal, anecdotal, less variability

Subjective ET

based on EIL, info about control delays

Objective ET

Most common, % of EIL, more conservative

Fixed EIL

More sophisticated, population dynamics, growth model, sampling

Descriptive ET

Faster population growth does what to ET

Shortens it

Time it takes for insect pop. to double

Doubling time

visual inspection, lures, netting, traps, pheromones, suction, indirect measures

Sampling

Most common evolution type used in farming

Directional