module 9 Flashcards
Integrated Pest Management (IPM)
Sustainable and beneficial pest management system
IPM uses
Fewer insecticides and pesticides than other methods
Uses non-chemical and chemical methods together
IPM leads to
Less affected groundwater and air
Protects beneficial species
IPM methods are reliant on
Inspection
Monitoring
surveillance
Good understanding of a pests ecological system
Tactics being used with environmental,etnal sustainability in mind are referred to as
Four-tiered IPM Implementation Approach
First step of Four-tiered IPM Implementation Approach
Evaluation and establishment of economic threshold for a target pest
Eradication of pests is
Rarely the goal of a IPM only keeping them at a non-critical level
Economic/action threshold
The point at which a grower needs to take action against a species
Economic injury level
Level at which pests cause damage and growers lose money
Economic/action threshold can be used to
Monitor pests
Measure crop damage
Correlate number of insects or damage with economic loss
An action threshold can be as low as
1 individual
Second step of IPM
Identification and monitoring
IPM includes monitoring
Before after and during control measures
Forms of monitoring
Identifying pest species and crop
Thorough monitoring should be able to
Identify pests before they become harmful
Easiest way to sample presence of insects
Manually viewing crop to see insect presence
Can be efficient because one to two samples can provide a manager to make a decision on control
In situ sampling
Visual observation
Effective for insects that are not active flyers, easy to find, or cause obvious damage to plants
Sweep netting
Manager uses a net to sample insects
Knockdown method
A container is used to pick up insects and the plant is knocked in order for insects to fall down into the container
Traps often use what kind of cues and why
Visual or chemical cues in order to reduce bycatch
Can also use light or heat
Lure
Synthetic chemicals with pheromones to attract insects
Funnel traps attract
Bark beetles and are long and segmented to mimic a tree trunk
Yellow sticky traps attract
Aphids and white flies
Bed bug traps use
Light and heat
Emerald Ash Borer bores into
Ash trees
Emerald ash borers are invasive in
North America
It is difficult to visually monitor emerald ash borers in ash trees because
It is difficult to find them until the tree is already dying
What helps predict patterns of spread of emerald ash borers
Pheromone traps as well as computer models
Third step of IPM
Prevention
Quarantine
Legal tool to prevent the spread of pests
Because pests are known to travel with certain materials
Those materials are banned from crossing certain borders
Before produce is allowed to be transported it must be
Approved to be allowed into the country that it is entering
Goods will be held in shipyards or airports until proven to be free of pests
Apple maggot fly leads to quarantine of produce in
Washington to prevent it from being a problem in all of Washington
Quarantine goods can be inspected
Visually or using tools
Goods found with pests are often
Destroyed
Preventative techniques against pests
Sealing areas from pests like using nets
Choosing crops that are resistant or unappealing to the pest
Manipulation of the environment to reduce attraction and establishment of the pest
Education and outreach is also an effective
Prevention plan
Fourth step of IPM
Control
Control methods are used when
Action thresholds have been breached and preventative strategies are no longer effective
All control methods must be measured by
Economics and efficiency
Risks to human health
Risks to environment
A pesticide is a
Chemical made to kill a pest
Insecticide
Chemicals used to kill insects
insecticide cost in a year in the US
56 billion
Criteria for what pesticide to use
Safety for users
Species specificity
Effectiveness
Persistence in the environment
Speed of action
Cost
Modes of application of insecticides
Stomach poisons
Contact poisons
Fumigants
Stomach poisons
Chemicals that impact insects through consumption
Bacillus thuringiensis (BT) works by
Creating open pores in the midgut of the insect, leading to starvation and death
Contact poisons
Enter insect through the body wall (are absorbed)
Fumigants
insecticides that are gaseous
Enter through spiracles that open into the tracheal system
Fumigants are effective because
They kill all life stages of insects
Fumigants are usually used in
Greenhouses and other contained areas because of the aerosol nature
types of chemical insecticides
Natural
Synthetic
Hormone analogues
Natural insecticides
Derived from natural things like plants
Toxins made by plants
Natural insecticides are not used in
Large scale efforts because extraction is costly
They breakdown easily and need to be reapplied often
Pyrethrum
Broad spectrum insecticide (kills large variety of insects)
Pyrethrum comes from
Chrysanthemum flowers
Pyrethrum contains
Pyrethrins
Pyrethrins
Low mammalian toxicity
Widely used to contain home and garden pests
Nicotine
Taken from tobacco plants
Water mixed with this is a natural insecticide
Why is nicotine no longer used
It is toxic to mammals
Natural insecticides are the template for
Synthetic ones
Synthetic insecticides are made by
Humans
DDT was first made in
WW2 to prevent typhus (spread by lice) and malaria (spread by mosquitoes )
Most synthetic insecticides are
Neurotoxins that either affect axons or synapses
Axonic poisons
affect the transmission of axon along the neuron
Chlorinated hydrocarbons is the first
Axonic poison
DDT is a
Chlorinated hydrocarbon
DDT was discontinued because
It had a negative impact on the environment and it was easily passed on with each trophic level through biomagnification
Pyrethroid
Synthetic chemicals that mimic pyrethrin
Highly toxic to insects by keeping sodium channels open, disrupting the flow of sodium and potassium
Effective at low doses and are not bad for the environment
Easy to manufacture and cheap
Organophosphates inhibit
AChE which breaks down the excitatory ACh
This leads to constant stimulation of Ash
This leads to constant movement and tremors, eventually leading to death
organophosphates are broken down by
UV light so they do not accumulate in the environment
Organophosphates are harmful
If they are inhaled or touched so they are not commercially used anymore
Organophosphates are still used to in cases that need a
Very effective insecticide
Neonicotinoids
Mimics nicotine
Mimics ACh but cannot be broken down by AChE
Used to prevent resistance to other types of insecticide
Neonicotinoids can be harmful to
Bees
Has been banned in some parts of the world
Muscle poisons
Attack muscle cells
Anthracillic diamides
Muscle poisons Used to help mitigate problem of insecticide resistance
Chlorantraniliprole
Muscle poison that stimulated calcium release of muscle cells, eventually depleting it
Leads to paralysis and death
Can be inhaled or enter by touch
Only harms insects which makes them for IPMs
Hormone analogues are often
Insect specific which makes them safe
Juvenile hormone analogues
Affects development of insects
Prevents the signal for moulting to occur which may prevent the insect from becoming a reproductively capable adult
Ecdysteroid moulting hormone analogues
Initiate moulting process
Cannot be cleared from the receptors
Prevents completion of moulting
Larvae and pupae die in the process
Methoxyfenozide
Ecdysteroid mimic that is effective against lepidopteran pests (caterpillars)
Interrupts moulting
Safe to integrate into IPMs because they bind to insect specific receptors
Hormone analogues also have predictable
Mortality which makes them effective
Non-target effects occur because many insecticides are
Broad spectrum (affect many insects)
Neurotoxins and broad spectrum insecticides can affect
Mammals and birds
Insecticide cause the most amount of
Pesticide poisoning
Guidelines to minimize environmental risk of insecticide
Nozzle size to maximize amount that lands on crop
specific dose
time of day to use insecticide
What part of the crop the insecticide is use on
Biobed
An area full of organisms great for breaking down pesticide
Is a closed system that does not allow water to move out
Resulting mix can be used as a fertilizer
Poor use of Insecticide can lead to
Resurgence
Replacement
Resistance
Resurgence
Rebound of a pest population to higher densities than before the insecticide was applied
Resurgence occurs mostly with
Broad spectrum insecticides that kill enemies of the pest
What pest feeds on rice plants
Brown planthopper
Brown planthopper resurgence of rice plants
Insecticide use kills predators of brown plant hoppers, the pest population then rebounded to a larger amount
Replacement
A broad spectrum insecticide kills off predators of a pest that is normally in check, turning them into a pest
Spider mite populations
Insecticide killed predators turning them into pests
Pest resistance
Reduction in sensitivity to a method of control
Resistance comes through
Natural selection
Anopheles mosquito
Malaria spreading mosquito gained resistance to insecticide
Behavioural resistance
When a pest modifies its behaviour to avoid a insecticide
Insects may move to less susceptible parts of the plant like under the leaf
Caterpillar behaviour resistance
Feeds slowly to allow insecticide to be detoxified
Metabolic resistance
When a poison is broken down before it reaches the target area by enzymes
Most common form of resistance
Metabolic resistance may gain this resistance by
Excreting toxin with waste
Shift harmful toxins to exocuticle to shed with next moult
Altered target site resistance
When a mutation of the target site makes the poison ineffective
Mosquito altered target site resistance
The mosquitoes developed altered target site resistance to JH
Penetration resistance
Adaptations which reduce the ability of a insecticide to penetrate the insect
Used in conjunction with other forms of resistance
Cross resistance
Development of resistance to one poison allows the insect to resist another
House fly cross resistance
Became resistant to DDT so then became resistant to other forms of synthetic insecticides
Biological qualities that promote evolution of resistance example
Insects that are concentrated in a small space have more pressure to evolve due to greater exposure
More offspring leads to
More opportunities to mutate a resistance
Short generation times are more
Beneficial to mutating a resistance
If the economic threshold is low
Managers will apply pesticide more often which leads to more opportunities for resistance
Applying a chemical before mating
Can promote resistance
Only resisted individuals survive and pass on resisted gene
Best way to prevent resistance is to implement
IPM
Not only using insecticide but other methods
Effective way to stop pest resistance
Provide a refuge for pest species where no insecticide is present
Surviving individuals of the pesticide area will mate with those that have not been exposed to pesticide
Cotton bollworm pest resistance method
Refuge pest method
