Insect Class Final Flashcards
Which plant disease is most associated with root rotting pathogens?
Monocyclic
Which reproductive system is considered the least dangerous when it comes to the pathogens ability to rapidly evolve around plant resistance or to become resistant to pesticides?
Asexual
Which of the following was NOT mentioned as a reason that fungi are the single most important group of plant pathogens?
- Always associated with vectors
The first major successful use of chemical control of a plant pathogen is a most associated with what country and crop?
France and grape production
Which statement best compares modern fungicides to fungicides from 100 years ago?
Modern fungicides are less harmful to non-target organisms, and have more resistance issues
Which of the following was NOT one of the “Darwinian assumptions” required for evolutionary selection to occur?
Some of the phenotypic variation is variable
Which of the following evolutionary innovations contributed to the broad success and abundance of insects?
- flight
- Complete metamorphosis
- Exoskeleton
Plant disease triangle?
- host
- pathogen
- environment
A pop. Of fungal pathogen splitting and adapting to specialize on two diff plant hosts is an example of what type of selection?
- disruptive selection
Which of the following are TRUE about insect physiology?
- Insects have a respiratory system
- Insect nerves have many similarities to vertebrae nerves
Which of the following are FALSe about the history of pest management?
- humans started using pesticides in 1939 when DDT was discovered
- The goal of integrated pest management is to limit the use of genetic control
Which of the following is true about insect taxonomy and evolution?
All insects are anthropods
Which of the following is true about insect development?
Holometabolous development reduces competition between adults and juveniles
Define EIL
the pest density at which the costs of control equal the benefits of control
Define gain threshold
the amount of yield that needs to be gained by the management action in order for the management option to be financially worthwhile34
Example of each type of control
Chemical -
Biological -
Genetic -
Cultural -
Physical -
Chemical - Acetylcholinesterase inhibitor
Biological - Predacious lady beetle
Genetic - Aphid-resistant soybean varietal
Cultural - Tillage
Physical - Netting
In what century was it first proven that microbes existed?
1600s
In what century was it first proved that microbes could cause plant disease?
1800s
List the 3 steps of the “pesticide treadmill”
- Pesticide used to control pests
- Pest developes resistance
- New pesticide required
What are some characteristics of a plant disease that would cause you to NOT want to develop a plant disease forecasting system for it?
- Disease is the same every year
- No control measures practical
- If damage it deals is minuscule
- If it’s not prevalent in your area
What are reasons developing countries are more prone to post-harvest losses?
- poor storage
- poor drying techniques
- lack of infrastructure to bring crop to market
What factors impact how we set an economic threshhold (ET) that are NOT part of determining the EIL?
- lead time
- insect pop. growth rate
What is the mission of a Land Grant Institution and how was this system funded?
Country took land from natives and gifted it to universities for agricultural education and research
HEAD, then THORAX, then ABDOMEN
All legs and wings are on THORAX
What’s a carrying capacity (K)? Is a severe pest more likely to have a higher K or lower than the EIL?
K = Max. pop. size environment can sustain, K > EIL with severe pests
C, V, YL, K
Cost, Value, Yield loss, proportion
What can act as both a phytoalexin and a phytoanticipan
- alkaloid
- phenolic compound
What’s “less durable” in the long run?
vertical resistance
Which are persistently transmitted (P) virus characteristics and what’s non-persistent (N)?
- Stylet borne
- Long incubation time
- Circulates through the whole insect
- Can be transmitted immediately after feeding
N - Stylet borne
P - Long incubation time
P - Circulates through the whole insect
N - Can be transmitted immediately after feeding
How does intercropping affect plant disease?
Often reduces disease
Which invasive organism is the “escape from enemies” hypothesis lease likely to explain why they are invasive?
Invasive microbes
Which of the following agricultural practices is most likely to encourage mycorrhizal colonization of your crop?
- Using cover crops
Potential mechanisms of pathogen biocontrols
- Hyper-parasitism
- Production of anti-microbial compounds
- Competition
- Induction of plant defenses
Strategies that can be used to manage pathogen pesticide resistance
- Rotate MOA’s
- Multi-use MOA’s
Ways to encourage the development of “suppressive soils”
- Compost
- Only ever planting one crop in a field, although very rare
Natural selection acts on your phenotype
AND your genotype determines your phenotype
GMO examples:
- Corn variety that produces dsRNAs against corn rootworm
- Corn that underwent targeted genome editing
If a crop protection strategy was made possible with “meditated transformation” what strategy is being used?
Genetic modification
Growing corn and soybean together in the same field in alternating rows at the same time is:
Intercropping
What’s true about augmentative biological control?
It uses species that are already present in the ecosystem as biocontrol agents
Can you buy bio control agents for your farm online? And does Spatial and temporal plant diversity both enhance the suppression of pests?
YES
What are the two ecological mechanisms that can explain why more plant diversity can suppress insect pest abundance?
- Enemies
- Resource concentration
Behavioral resistance vs. Physiological resistance
Behavioral resistance means pest learn to avoid things that kill them, physiological - they build a tolerance to it
Inoculative vs. Inundative
Inoculative - releasing a smaller amount of natural enemies expecting them to reproduce and stick around a couple of generations
Inundative - Releasing TONS of natural enemies not expecting them to reproduce and be gone in a single generation
What defines classical biological control?
Import with co-evolved enemy from native range
What defines neo-classical biological control?
The enemy used to control did not co-evolve with the target
Strategies that might be employed in a conservation biological control approach:
- removing the (natural enemy to your pest)’s predators
- Increasing the natural enemy to your pest’s resources
Evolutionary history of bees: what bees are, when they evolved, their relationship with flowers, where bees nest
- Hymenoptera, 20,000 bee species
- First appeared about 123 million years ago
- Cretotrigona prisca (1st bee) 65-75 million years ago
- Bees and flowers evolve together, and different flowers place pollen on different parts of bee’s bodies
- Some bees nest in flower petals, termite mounds, the ground (most popular), INSIDE twigs
solitary, social, and parasitic bees
- Social: Work as a team and bees have “roles”
- Solitary: (80% of bees), solitary bee females establish and provision nests on their own with no assistance from other individuals
- Parasitic: Mom lays eggs with stranger bees and when her bees come out they kill the host larvae and eat the pollen ball “steal pollen”
Importance of bees to our food systems: how much food and what kinds of food rely on pollinators, impacts of pollinated crop foods on human health
- 2/3 of crops, 1 in 3 bites of food
- Almonds, nuts, kiwis, strawberries, blueberries, watermelon
Honey bee “migration”
- Put honeybees on semis and take them to California to pollinate almonds in February,
What are some specific reasons pollinators have been considered under threat recently?
- Loss of habitat
- Insecticides
- Disease
Distinguish between symbiosis and mutualism
- Mutualism is when two species are HELPING each other, Symbiosis just means different species are living in close association, could be positive or negative.
What is a facultative mutualism? An obligate mutualism? Give an example of each
- An obligate mutualism means the parasite can’t live without the host. Ex: Lice
- A facultative parasite is an organism that may resort to parasitic activity, but does not absolutely rely on any host for completion of its life cycle. Ex: Candida
Examples of mutualisms (insect-insect, insect-plant, insect-microbe): what are the benefits/roles of each partner?
- insect-insect: Ants and honeydew producing insects, ants get the sugar from honeydew and then protect the insect
- insect-plant: Figs + fig wasps, Figs have internal flowers obligately pollinated by fig wasps that live and lay eggs inside the fruit
Types of services/impacts conferred by microbial symbionts (in insects) (nutrition, defense, reproductive manipulation)
- Nutrition: Microbe helps make up the diet deficiencies of insect
- Defense: Protect from Parasitoids, Parasites, Fungal infections
- Reproductive manipulation: Infected males make defective sperm that needs a matching infection in the egg to be “rescued”
What are the 3 ways that Streptomyces populations differ between disease conducive and suppressive soils?
- Suppressive Soil has MORE Streptomyces
- SS Streptomyces are better antibiotic producers
- SS Streptomyces produce a greater diversity of antibiotic phenotypes
(More, better, more diverse disease suppression)
How does “niche-differentiation” affect whether a soil is more suppressive or less?
RESOURCE COMPETITION IS IMPORTANT TO FITNESS
