VA CORE MANUAL: APPLYING
PESTICIDES CORRECTLY: UNIT 2.
PRINCIPLES OF PEST CONTROL - TEST
YOUR KNOWLEDGE
Explain the differences between key pests, occasional pests, and secondary pests. -
ANSWER-Key pests are nearly always present and require regular control. Occasional
pests are migratory or cyclical and may require intermittent control. Secondary pests
require control only under certain conditions, such as the elimination of a key pest or the
absence of a natural host.
What should you do first if you observe damage to a plant, animal, or valuable product
or commodity? - ANSWER-Identify the cause.
How can pest identification help you develop a good pest control strategy? - ANSWER-
It allows you to determine basic information about the pest, including its life cycle and
when it is most susceptible to control measures.
What should you do first if you discover a pest that may need to be controlled? -
ANSWER-Make sure that it is actually responsible for the damage or problem observed.
Then, accurately identify the pest.
Name at least three Virginia Tech facilities that can help you identify a pest and
diagnose an infestation. - ANSWER-The Weed ID Clinic, the Plant Disease Clinic, the
Nematode Assay Laboratory, and the Insect Identification Laboratory.
Why do weeds present such a challenge to pest managers? - ANSWER-Weeds are
often hardy, aggressive, and tolerant of harsh conditions. Many produce large numbers
of seeds, which can spread over a wide area and remain dormant for a long time.
Weeds are fierce competitors for soil moisture, nutrients, and sunlight.
How can you tell a monocot from a dicot plant? - ANSWER-Monocots (grasses and
sedges) have one seed leaf, parallel leaf veins, flower parts in multiples of three, and
fibrous roots. Dicots (broadleaves) have two seed leaves, broad or narrow leaves,
netlike veins, and flower parts in multiples of four or five. They usually have taproots.
Name the five basic pest groups discussed in this unit. - ANSWER-Weeds, diseases
and parasites, arthropods, mollusks, and vertebrates.
Why are perennial weeds usually harder to control than annual or biennial weeds? -
ANSWER-Perennials do not die after a one- or two-year life cycle. Some may live for
, many years. They also have underground parts to store food and produce new growth
each growing season. These parts are harder to reach and control.
Name the pathogens that cause most plant and animal diseases. - ANSWER-Fungi,
bacteria, mycoplasmas, and viruses.
What sorts of symptoms do viral plant diseases often cause? - ANSWER-Stunting,
yellow rings on leaves, wilting, and mosaic patterns (yellow or bleached streaks).
How can parasites such as flies, ticks, and lice harm livestock and other animals? -
ANSWER-These parasites may host and transmit diseases on animals, causing blood
loss and physical damage. Parasites can reduce the rate of weight gain, cause a
decrease in milk or egg production, interfere with reproduction, and lower the infected
animal's resistance to disease.
How do mites harm plants? - ANSWER-They suck plant juices, eat the undersides of
leaves, and disfigure the plants they feed on.
What types of damage do vertebrate pests cause? - ANSWER-Vertebrates may
damage property, agriculture, and/or natural resources. They may also threaten human
health and safety or spread disease. Some vertebrates may destroy feed or eat the
seeds or fruit of crops. Others compete with livestock, cause traffic accidents, and
destroy residential landscapes. Some vertebrate predators feed on domestic animals.
What is an economic threshold? - ANSWER-The level at which economic losses
caused by pest damage, if the pest population continued to grow, would be greater than
the cost of controlling the pests. Reaching an economic threshold usually prompts some
type of pest control action.
What is the main difference between indoor and outdoor vertebrate pest control? -
ANSWER-Eradication vs. suppression. Indoor vertebrate control usually centers on
eradication of rodent pests. Outdoor vertebrate control focuses on suppressing
nuisance animals such as coyotes, raccoons, or beavers to an acceptable level.
How do plant-parasitic nematodes harm plants? - ANSWER-By attacking the roots,
stems, and leaves. Nematode root feeding interferes with a plant's ability to take up
water and nutrients. Infected plants wilt and seem to be suffering from a lack of water or
nutrients.
How do mollusks harm plants? - ANSWER-By feeding on foliage and fruit. Mollusks
reduce the value of commercial produce if they feed on harvested plants and fruit.
What is the difference between gradual and complete metamorphosis? Why is it
important to know the life cycle stage of an insect? - ANSWER-Gradual metamorphosis
includes three stages: egg, nymph, and adult. There is no pupa stage. Complete
metamorphosis includes four stages: egg, larva, pupa, and adult. Insects that develop
PESTICIDES CORRECTLY: UNIT 2.
PRINCIPLES OF PEST CONTROL - TEST
YOUR KNOWLEDGE
Explain the differences between key pests, occasional pests, and secondary pests. -
ANSWER-Key pests are nearly always present and require regular control. Occasional
pests are migratory or cyclical and may require intermittent control. Secondary pests
require control only under certain conditions, such as the elimination of a key pest or the
absence of a natural host.
What should you do first if you observe damage to a plant, animal, or valuable product
or commodity? - ANSWER-Identify the cause.
How can pest identification help you develop a good pest control strategy? - ANSWER-
It allows you to determine basic information about the pest, including its life cycle and
when it is most susceptible to control measures.
What should you do first if you discover a pest that may need to be controlled? -
ANSWER-Make sure that it is actually responsible for the damage or problem observed.
Then, accurately identify the pest.
Name at least three Virginia Tech facilities that can help you identify a pest and
diagnose an infestation. - ANSWER-The Weed ID Clinic, the Plant Disease Clinic, the
Nematode Assay Laboratory, and the Insect Identification Laboratory.
Why do weeds present such a challenge to pest managers? - ANSWER-Weeds are
often hardy, aggressive, and tolerant of harsh conditions. Many produce large numbers
of seeds, which can spread over a wide area and remain dormant for a long time.
Weeds are fierce competitors for soil moisture, nutrients, and sunlight.
How can you tell a monocot from a dicot plant? - ANSWER-Monocots (grasses and
sedges) have one seed leaf, parallel leaf veins, flower parts in multiples of three, and
fibrous roots. Dicots (broadleaves) have two seed leaves, broad or narrow leaves,
netlike veins, and flower parts in multiples of four or five. They usually have taproots.
Name the five basic pest groups discussed in this unit. - ANSWER-Weeds, diseases
and parasites, arthropods, mollusks, and vertebrates.
Why are perennial weeds usually harder to control than annual or biennial weeds? -
ANSWER-Perennials do not die after a one- or two-year life cycle. Some may live for
, many years. They also have underground parts to store food and produce new growth
each growing season. These parts are harder to reach and control.
Name the pathogens that cause most plant and animal diseases. - ANSWER-Fungi,
bacteria, mycoplasmas, and viruses.
What sorts of symptoms do viral plant diseases often cause? - ANSWER-Stunting,
yellow rings on leaves, wilting, and mosaic patterns (yellow or bleached streaks).
How can parasites such as flies, ticks, and lice harm livestock and other animals? -
ANSWER-These parasites may host and transmit diseases on animals, causing blood
loss and physical damage. Parasites can reduce the rate of weight gain, cause a
decrease in milk or egg production, interfere with reproduction, and lower the infected
animal's resistance to disease.
How do mites harm plants? - ANSWER-They suck plant juices, eat the undersides of
leaves, and disfigure the plants they feed on.
What types of damage do vertebrate pests cause? - ANSWER-Vertebrates may
damage property, agriculture, and/or natural resources. They may also threaten human
health and safety or spread disease. Some vertebrates may destroy feed or eat the
seeds or fruit of crops. Others compete with livestock, cause traffic accidents, and
destroy residential landscapes. Some vertebrate predators feed on domestic animals.
What is an economic threshold? - ANSWER-The level at which economic losses
caused by pest damage, if the pest population continued to grow, would be greater than
the cost of controlling the pests. Reaching an economic threshold usually prompts some
type of pest control action.
What is the main difference between indoor and outdoor vertebrate pest control? -
ANSWER-Eradication vs. suppression. Indoor vertebrate control usually centers on
eradication of rodent pests. Outdoor vertebrate control focuses on suppressing
nuisance animals such as coyotes, raccoons, or beavers to an acceptable level.
How do plant-parasitic nematodes harm plants? - ANSWER-By attacking the roots,
stems, and leaves. Nematode root feeding interferes with a plant's ability to take up
water and nutrients. Infected plants wilt and seem to be suffering from a lack of water or
nutrients.
How do mollusks harm plants? - ANSWER-By feeding on foliage and fruit. Mollusks
reduce the value of commercial produce if they feed on harvested plants and fruit.
What is the difference between gradual and complete metamorphosis? Why is it
important to know the life cycle stage of an insect? - ANSWER-Gradual metamorphosis
includes three stages: egg, nymph, and adult. There is no pupa stage. Complete
metamorphosis includes four stages: egg, larva, pupa, and adult. Insects that develop
