lesson 8 Flashcards
rarara
any entity living or non-living that cause damage to crops
pests
What are the types of plant pests
- Plant Pathogens
- Insect Pests
- Weeds
- Mollusks
- Vertebrate Pests
disease causing organisms
Plant pathogens
Eukaryotes that may either be parasitic or saprophytic
Fungi
What do fungi produce which is like a thread-like structure?
mycelia and spores
Unicellular organisms that reproduce by binary
Bacteria
Neither living nor non-living entities
Viruses
What are viruses composed of?
nucleic acids surrounded by a protein coat
When do viruses become active?
Upon invading a host cell, otherwise they are dormant
Threadlike worms that are commonly soil-borne and can penetrate the plant epidermis.
Nematodes
What are the ways on how plant pathogens enter a plant/
- Wounds or natural openings like stomates and leaf scars
- Plant epidermis
- Insect vector
- Dispersed when using infected planting materials
What are the modes of damages of plant pathogens
- Kill the host cell or slow down their metabolism
- Block the passage of food, water, and nutrients
- Block sunlight on the surface of leaves or slow down the diffusion of gases
- May consume the cell content
- Viruses - take over the genetic control of plant cells to produce viral cells instead of host cells
What do viruses produce?
viral cell
evidences of the presence of the disease
Symptoms
used to determine the disease that the plant is suffering
Symptoms
proof of the presence of the pathogen on the infected plants
Signs
further confirm the presence of a disease in the plant
Signs
arthropods belonging to class of Insecta
Insects
How many body parts does a insect have?
3
What kind of appendages do insects have
jointed
How many pairs of legs does an insect have?
3
What does the nature of damage depend on?
Nature of damage
What kind of chewing insects have to feed directly on plant parts?
strong mandibles
What do sucking mouthparts serve as?
vectors of dieases
beetles and weevils
Coleoptera
grasshoppers, katydids, locusts, crickets
Orthoptera
butterflies and moths
Lepidoptera
fruit flies, whorl maggots
Diptera
bugs, aphids, cicadas, planthoppers, leaf hoppers, scale insects
Hemiptera
thrips
Thysanoptera