IOWA 3OT PESTICIDE STUDY GUIDE 2026 QUESTIONS AND
SOLUTIONS RATED A+
✔✔List abiotic factors affecting ornamental plants - ✔✔Herbicide drift
Soil pH
soil compaction
salt injury
mechanical damage
water stress
✔✔List the methods to manage plant diseases caused by fungi - ✔✔Selection of
resistant species, correct site placement, plant spacing, mulching, watering during
prolonged dry periods
Removed infected tissues during appropriate time and destroy. Clean tools.
Fungicides are usually protectants. Limited number are systemic.
Common fungal diseases in iowa that warrant applications are apple scab, oak wilt, and
rhizosphaera needle cast.
Examples of fungicide active ingredient are benimidazoles, thiophanates, or
dicarboximides
✔✔fungi - ✔✔Diverse group of organism with many different forms and life cycles.
Fungal cell walls contain chitin but do not contain the biochemical machinery to perform
photosynthesis, therefore they cannot produce their own food.
Exist as either a saprophyte (lives on dead or decaying matter) or as a parasite.
Filamentous growth (cells elongate but do not divide) is called hyphae that form a fungal
mass called a mycelium.
Reproduce by sexual, asexual, or both mechanisms to produce spores.
✔✔Bacteria - ✔✔Bacteria are microscopic, one-celled organisms.
Reproduce asexually by dividing in half - large populations can be formed quickly.
High humidity, crowded plant spacing, and poor air circulation are favorable conditions
for bacterial growth.
Bacteria must enter plants through wounds or natural openings.
Identification can be done through lab assistance or antigens
,✔✔List the methods to manage plant diseases caused bacteria - ✔✔Focuses on
prevention and good cultural practices
If bacterial disease is located, dig up plant along with the soil and burn it.
Diseased tissues should be pruned from established trees and shrubs.
The few bactericides that are available can serve to protect healthy plants but are not
highly successful in controlling bacterial diseases.
One exception would be fire blight
Examples of bactericides active ingredients: hydrogen peroxides, glucopyranosyl
antibiotics, etc.
✔✔List the methods to manage plant diseases caused viruses - ✔✔Transmitted to other
plants through sap by wounds, contaminated tools, worker hands, or insect vectors
feeding on the plant.
Ornamental pest manager must use sanitation, monitoring for symptoms, and control of
insect and mite vectors as the primary methods against plant viruses.
There are not pesticides that can cure a virus infected plant or protect a plant.
✔✔Viruses - ✔✔Non-cellular, parasitic organism that are visible only with electron
microscopes.
Consist of nucleic acids (RNA and DNA) surrounded by protein.
Generally do not kill host, but alter their appearance by distorting or stunting leaf growth.
Use host's cellular machinery to produce new viruses which are then transferred to
other host cells.
✔✔List the methods to manage plant diseases caused nematodes - ✔✔Management is
difficult
Cultural methods include removal and destruction of dead or dying host plants
Genetic methods involve using nematode resistant species.
There is ONE nematode registered for use on ornamentals in the landscape:
biopesticides (NC)
✔✔Nematodes - ✔✔Plant parasitic nematodes are microscopic roundworms usually
infecting root systems but can be found in above ground portions.
, Have needle like mouth part that is used to pierce plant tissue to inject enzymes to
digest plant tissues and withdraw the floods as its food.
Reproduce within their host and migrate to new hosts short distances through soil or
vectors
✔✔State how plant diseases are transmitted - ✔✔Fungi - spores
Bacteria - wounds or natural openings of plants
Viruses - sap by wounds, tools, workers hands, or insect vectors
Nematodes - vectors or soil
✔✔Define skeletonize - ✔✔Feeding damage by insects with chewing mouthparts that
reduce host leaves to a skeleton of main and secondary veins, with little to no leaf blade
remaining
✔✔List the three types of insects that can be leaf feeders on ornamentals - ✔✔Beetle
Caterpillars
Sawflies
✔✔sawflies - ✔✔Look like caterpillars, but are the immature stage of small, non stinging
wasps
What distinguishes caterpillars from sawflies are a single pair of large eyes and more
than five pairs of abdominal legs (prolegs)
✔✔List the three examples of insects that can be leaf feeders on ornamentals -
✔✔Japanese beetle
Bagworm
European pine sawfly
✔✔State the three situations when insecticide sprays are ineffective against leaf-
feeding insects - ✔✔Larvae are large
Beetles have been feeding for several days
Host leaves are browned or completely eaten
SHOULD be applied when leaf feeders are still small.
For japanese beetles, two treatments are usually required.
✔✔Explain the danger of using contact and systemic insecticides in reference to
pollinators - ✔✔Avoid spraying blooming plants with insecticides that are toxic to
pollinators.
Do not use systemic insecticides on host plants that attract pollinators at anytime during
the growing season as it may last within host plants for several years.
Pollinators that feed on these plants will likely die.
SOLUTIONS RATED A+
✔✔List abiotic factors affecting ornamental plants - ✔✔Herbicide drift
Soil pH
soil compaction
salt injury
mechanical damage
water stress
✔✔List the methods to manage plant diseases caused by fungi - ✔✔Selection of
resistant species, correct site placement, plant spacing, mulching, watering during
prolonged dry periods
Removed infected tissues during appropriate time and destroy. Clean tools.
Fungicides are usually protectants. Limited number are systemic.
Common fungal diseases in iowa that warrant applications are apple scab, oak wilt, and
rhizosphaera needle cast.
Examples of fungicide active ingredient are benimidazoles, thiophanates, or
dicarboximides
✔✔fungi - ✔✔Diverse group of organism with many different forms and life cycles.
Fungal cell walls contain chitin but do not contain the biochemical machinery to perform
photosynthesis, therefore they cannot produce their own food.
Exist as either a saprophyte (lives on dead or decaying matter) or as a parasite.
Filamentous growth (cells elongate but do not divide) is called hyphae that form a fungal
mass called a mycelium.
Reproduce by sexual, asexual, or both mechanisms to produce spores.
✔✔Bacteria - ✔✔Bacteria are microscopic, one-celled organisms.
Reproduce asexually by dividing in half - large populations can be formed quickly.
High humidity, crowded plant spacing, and poor air circulation are favorable conditions
for bacterial growth.
Bacteria must enter plants through wounds or natural openings.
Identification can be done through lab assistance or antigens
,✔✔List the methods to manage plant diseases caused bacteria - ✔✔Focuses on
prevention and good cultural practices
If bacterial disease is located, dig up plant along with the soil and burn it.
Diseased tissues should be pruned from established trees and shrubs.
The few bactericides that are available can serve to protect healthy plants but are not
highly successful in controlling bacterial diseases.
One exception would be fire blight
Examples of bactericides active ingredients: hydrogen peroxides, glucopyranosyl
antibiotics, etc.
✔✔List the methods to manage plant diseases caused viruses - ✔✔Transmitted to other
plants through sap by wounds, contaminated tools, worker hands, or insect vectors
feeding on the plant.
Ornamental pest manager must use sanitation, monitoring for symptoms, and control of
insect and mite vectors as the primary methods against plant viruses.
There are not pesticides that can cure a virus infected plant or protect a plant.
✔✔Viruses - ✔✔Non-cellular, parasitic organism that are visible only with electron
microscopes.
Consist of nucleic acids (RNA and DNA) surrounded by protein.
Generally do not kill host, but alter their appearance by distorting or stunting leaf growth.
Use host's cellular machinery to produce new viruses which are then transferred to
other host cells.
✔✔List the methods to manage plant diseases caused nematodes - ✔✔Management is
difficult
Cultural methods include removal and destruction of dead or dying host plants
Genetic methods involve using nematode resistant species.
There is ONE nematode registered for use on ornamentals in the landscape:
biopesticides (NC)
✔✔Nematodes - ✔✔Plant parasitic nematodes are microscopic roundworms usually
infecting root systems but can be found in above ground portions.
, Have needle like mouth part that is used to pierce plant tissue to inject enzymes to
digest plant tissues and withdraw the floods as its food.
Reproduce within their host and migrate to new hosts short distances through soil or
vectors
✔✔State how plant diseases are transmitted - ✔✔Fungi - spores
Bacteria - wounds or natural openings of plants
Viruses - sap by wounds, tools, workers hands, or insect vectors
Nematodes - vectors or soil
✔✔Define skeletonize - ✔✔Feeding damage by insects with chewing mouthparts that
reduce host leaves to a skeleton of main and secondary veins, with little to no leaf blade
remaining
✔✔List the three types of insects that can be leaf feeders on ornamentals - ✔✔Beetle
Caterpillars
Sawflies
✔✔sawflies - ✔✔Look like caterpillars, but are the immature stage of small, non stinging
wasps
What distinguishes caterpillars from sawflies are a single pair of large eyes and more
than five pairs of abdominal legs (prolegs)
✔✔List the three examples of insects that can be leaf feeders on ornamentals -
✔✔Japanese beetle
Bagworm
European pine sawfly
✔✔State the three situations when insecticide sprays are ineffective against leaf-
feeding insects - ✔✔Larvae are large
Beetles have been feeding for several days
Host leaves are browned or completely eaten
SHOULD be applied when leaf feeders are still small.
For japanese beetles, two treatments are usually required.
✔✔Explain the danger of using contact and systemic insecticides in reference to
pollinators - ✔✔Avoid spraying blooming plants with insecticides that are toxic to
pollinators.
Do not use systemic insecticides on host plants that attract pollinators at anytime during
the growing season as it may last within host plants for several years.
Pollinators that feed on these plants will likely die.
