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Ontario Pesticide Landscape Exam study materials
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Ontario Pesticide Landscape Exam practice questions

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Question 1Pest Identification and Biology

A landscape technician finds a chewing insect with three pairs of true legs on the thorax and five pairs of fleshy prolegs on the abdomen. Which pest group does this specimen most likely belong to?

  1. Sawfly larva
  2. Beetle larva
  3. Moth caterpillar Correct answer.
  4. Fly maggot

Explanation

Caterpillars of moths and butterflies typically bear prolegs on abdominal segments three through six plus one pair on the last segment, giving five pairs. Sawfly larvae resemble caterpillars but usually have more than five pairs of prolegs and lack the crochets seen on caterpillar prolegs. Counting prolegs is the standard field separation of these two chewing groups.

Question 2Pest Identification and Biology

Which insect order is characterized by two membranous wings, hind wings reduced to knob-like halteres, and mouthparts adapted for sponging?

  1. Hymenoptera
  2. Diptera Correct answer.
  3. Hemiptera
  4. Lepidoptera

Explanation

Diptera, the true flies, carry only one pair of functional wings; the hind wings are modified into halteres used for balance. Their mouthparts are commonly sponging or lapping rather than chewing. No other major order combines a single wing pair with halteres.

Question 3Pest Identification and Biology

Aphids are often found clustered on tender new shoots with their mouthparts inserted into plant tissue. Which feeding category best describes aphids?

  1. Chewing
  2. Piercing-sucking Correct answer.
  3. Sponging
  4. Rasping-sucking

Explanation

Aphids use needle-like stylets to penetrate plant tissue and withdraw phloem sap, which is the piercing-sucking habit. This feeding style removes sap without removing leaf tissue, so damage appears as curling, stunting, and honeydew rather than holes. Chewing and rasping insects remove or scar plant material.

Question 4Pest Identification and Biology

Which life stage of a scale insect is the active, mobile stage that spreads the insect to new stems?

  1. Egg
  2. Puparium
  3. Crawler Correct answer.
  4. Adult female

Explanation

The crawler is the newly hatched first-instar nymph, which has legs and moves to find a feeding site before settling. Once settled, most scales become immobile and secrete a waxy cover. Eggs and adult females are largely stationary, so crawlers drive dispersal.

Question 5Pest Identification and Biology

Spider mites are not true insects. Which body feature best separates them from insects?

  1. They have four pairs of legs and no antennae Correct answer.
  2. They have wings but no legs
  3. They have three body segments and one pair of antennae
  4. They have a single body region and six legs

Explanation

Mites are arachnids, and adults bear four pairs of legs with the body divided into two regions and no antennae. Insects have three pairs of legs, three body regions, and one pair of antennae. This leg count is the quickest field check when mite damage is suspected.

Question 6Pest Identification and Biology

Which insect order contains both the larvae known as white grubs and adults such as Japanese beetle?

  1. Diptera
  2. Lepidoptera
  3. Hymenoptera
  4. Coleoptera Correct answer.

Explanation

Beetles (Coleoptera) have hard, sheath-like forewings and chewing mouthparts, and their larvae include the C-shaped white grubs found in turf and soil. Lepidoptera larvae are caterpillars, and Diptera larvae are maggots. Sawfly larvae, though grub-like in appearance, belong to Hymenoptera.

Question 7Pest Identification and Biology

A client reports slime trails and irregular holes with smooth edges on hosta leaves after rainfall. Which pest is most consistent with these signs?

  1. Slugs Correct answer.
  2. Leafhoppers
  3. Aphids
  4. Cutworms

Explanation

Slugs leave a dried mucous trail and chew ragged holes with smooth margins, and their damage is heaviest in damp conditions. Cutworms sever seedlings near the soil line rather than leaving slime. Leafhoppers and aphids feed by sucking sap and do not produce slime trails.

Question 8Pest Identification and Biology

Which pest is a mollusc rather than an insect or mite?

  1. Snail Correct answer.
  2. Springtail
  3. Sowbug
  4. Earwig

Explanation

Snails and slugs are gastropod molluscs, with a soft unsegmented body and a muscular foot. Earwigs and springtails are insects, and sowbugs are terrestrial crustaceans. Recognizing the group guides control choices, since mollusc baits differ from insecticide products.

Question 9Pest Identification and Biology

A caterpillar is found feeding inside a rolled leaf on an ornamental shrub. Which feeding guild does this insect represent?

  1. Root feeder
  2. Leaf miner
  3. Borer
  4. Leaf tier or roller Correct answer.

Explanation

Leaf tiers and rollers are larvae that bind or roll foliage with silk and feed within the shelter they create. Leaf miners feed between the leaf surfaces and leave visible mines, while borers tunnel into stems or trunks. Root feeders work below the soil surface and are not found in rolled leaves.

Question 10Pest Identification and Biology

Which feature distinguishes damage by a piercing-sucking insect from damage by a chewing insect on foliage?

  1. Girdled bark at the soil line
  2. Clean circular holes cut from leaf margins
  3. Stippling, chlorosis, or curling without removed tissue Correct answer.
  4. Missing leaf tissue with jagged edges

Explanation

Piercing-sucking insects withdraw cell contents or sap through stylets, leaving stippling, chlorosis, or distorted growth while the leaf tissue itself remains. Chewing insects physically remove tissue, producing holes, notches, or skeletonized leaves. Observing whether tissue is missing is a reliable first diagnostic step.

Question 11Pest Identification and Biology

A greenhouse crop shows silvery stippling on leaves, tiny black fecal specks, and fine webbing on leaf undersides. Which pest is most likely?

  1. Spider mites Correct answer.
  2. Whiteflies
  3. Fungus gnats
  4. Thrips

Explanation

Spider mites remove cell contents, causing pale stippling, and produce fine silk webbing plus dark fecal spots on the undersides of leaves. Thrips also cause silvering but leave black fecal flecks without webbing and often distort new growth. Whiteflies and fungus gnats do not produce leaf webbing of this kind.

Question 12Pest Identification and Biology

Which statement correctly describes the life cycle of an insect with gradual metamorphosis, such as an aphid or a plant bug?

  1. Egg, nymph, adult Correct answer.
  2. Egg, larva, pupa, adult
  3. Egg, larva, adult
  4. Nymph, pupa, adult

Explanation

Gradual, or incomplete, metamorphosis proceeds from egg to nymph to adult, with nymphs resembling small wingless adults and molting several times. Complete metamorphosis adds a pupal stage between larva and adult. Recognizing the type of metamorphosis helps target the stage most vulnerable to control.

Question 13Pest Identification and Biology

A turf manager observes irregular dead patches in late summer and finds C-shaped white grubs in the top few centimetres of soil. Which management timing is most consistent with grub biology?

  1. Treat when young larvae are feeding near the surface in late summer Correct answer.
  2. Treat in midwinter when grubs are deepest
  3. Treat only after adult emergence the following spring
  4. Treat when adults are actively laying eggs in early summer

Explanation

White grubs feed most actively and remain closest to the soil surface as young larvae in late summer and early autumn, which is when soil-applied controls work best. By midwinter grubs move deeper and are harder to reach. Spring treatments target large larvae that are about to pupate and are less effective.

Question 14Pest Identification and Biology

Which characteristic is typical of thrips damage on flowers and foliage?

  1. Large ragged holes at leaf margins
  2. Sudden wilting of the entire plant
  3. Skeletonized leaves with only veins remaining
  4. Silvery scarring and distorted growth with dark fecal flecks Correct answer.

Explanation

Thrips rasp surface cells and suck the released contents, leaving silvery patches, flecks of dark excrement, and distorted new growth. Skeletonized leaves result from chewing insects that leave veins intact. Sudden whole-plant wilting points to root or vascular problems rather than thrips.

Question 15Pest Identification and Biology

A landscape crew finds small, soft-bodied insects with cornicles on the tips of new growth, and the leaves are sticky and sooty. Which pest and associated problem does this describe?

  1. Caterpillars producing frass
  2. Leafhoppers producing spittle
  3. Scale insects producing wax
  4. Aphids producing honeydew Correct answer.

Explanation

Aphids secrete honeydew from their cornicles, and sooty mould grows on the sugary deposits, turning foliage black and sticky. Scale insects also produce honeydew but are not soft-bodied and mobile on shoot tips. Frass and spittle are not sticky sugary coatings.

Question 16Pest Identification and Biology

Which insect group includes species whose larvae are legless and live in soil, where they may damage roots of container plants?

  1. Lady beetles
  2. Sawflies
  3. Fungus gnats Correct answer.
  4. Lacewings

Explanation

Fungus gnat larvae are small, legless maggots with dark heads that inhabit moist growing media and feed on roots, fungi, and organic matter. Sawfly larvae are external leaf feeders with prolegs. Lady beetle and lacewing larvae are predatory and do not damage roots.

Question 17Pest Identification and Biology

A pest is described as having a shield-shaped body, piercing-sucking mouthparts, and a life cycle in which nymphs and adults both feed on the same host. Which order does this best describe?

  1. Coleoptera
  2. Diptera
  3. Hemiptera Correct answer.
  4. Lepidoptera

Explanation

Hemiptera, the true bugs, typically have shield-shaped bodies and piercing-sucking mouthparts, and both nymphs and adults feed on plant sap using gradual metamorphosis. Coleoptera have chewing mouthparts and hard forewings. Diptera and Lepidoptera do not combine a shield body with piercing-sucking mouthparts.

Question 18Pest Identification and Biology

Which environmental condition most favors rapid population growth of spider mites on landscape plants?

  1. Flooded soil around the root zone
  2. Cool, humid weather with frequent rain
  3. Hot, dry weather with dusty foliage Correct answer.
  4. Deep shade with constant moisture

Explanation

Spider mites reproduce fastest in hot, dry conditions, and dusty leaves further favor them while suppressing fungal pathogens that would otherwise limit them. Humid, rainy weather tends to reduce mite populations. Soil moisture and shade are less directly tied to mite outbreaks.

Question 19Pest Identification and Biology

A defoliating caterpillar is found on shade trees. Which trait best identifies it as a caterpillar rather than a sawfly larva?

  1. A hardened head capsule
  2. More than six pairs of abdominal prolegs
  3. Feeding in groups on foliage
  4. Prolegs with tiny hooks called crochets Correct answer.

Explanation

Caterpillar prolegs bear minute hooks called crochets, which sawfly prolegs lack. Sawflies also tend to have more than five pairs of prolegs, while caterpillars typically have five or fewer. A hardened head capsule and group feeding occur in both groups and do not separate them.

Question 20Pest Identification and Biology

Which evidence most directly indicates that a borer is responsible for branch dieback on a woody shrub?

  1. Chewing damage on the outer leaves
  2. Sticky honeydew on the upper leaf surfaces
  3. Fine webbing on the undersides of leaves
  4. Sawdust-like frass and an entry hole on the stem Correct answer.

Explanation

Borers tunnel into stems or trunks, pushing out sawdust-like frass and leaving a visible entry or exit hole near the damaged tissue. Leaf chewing, honeydew, and leaf webbing reflect external feeders or sap feeders. Locating frass and an entry hole confirms internal feeding.

Question 21Pest Identification and Biology

Which statement about the overwintering stage of many temperate-zone plant-feeding insects is generally true?

  1. Most species overwinter as active feeding adults
  2. Most species overwinter as feeding nymphs on new growth
  3. All species overwinter as first-instar larvae on foliage
  4. Many species overwinter as eggs or pupae in protected sites Correct answer.

Explanation

In temperate climates, many plant-feeding insects pass winter as eggs or pupae in protected locations such as bark crevices, leaf litter, or soil, which allows them to survive cold and lack of host foliage. Active feeding stages are not sustainable through winter. Knowing the overwintering stage helps time dormant controls.

Question 22Pest Identification and Biology

A sample of damaged turf shows patches that pull up easily because roots are severed, and the turf has a spongy feel. Which pest group is the most probable cause?

  1. Leaf-feeding sod webworms
  2. Stem-sucking aphids
  3. Above-ground chinch bugs
  4. Soil-dwelling white grubs Correct answer.

Explanation

White grubs feed on turf roots, so damaged turf lifts away easily and feels spongy because the root anchor is gone. Chinch bugs feed above ground and cause yellowing without root loss. Sod webworms remove leaf blades, leaving roots intact.

Question 23Pest Identification and Biology

Which observation would most strongly suggest that damage on a leaf was caused by a leaf miner rather than a chewing insect?

  1. A winding pale trail confined between the upper and lower leaf surfaces Correct answer.
  2. Skeletonized tissue with veins left intact
  3. A missing section of leaf margin with smooth edges
  4. A ragged hole extending through the full thickness of the leaf

Explanation

Leaf miner larvae feed between the epidermal layers, producing meandering mines visible as pale trails while the leaf surfaces remain intact. Chewing insects remove tissue through the leaf thickness or from margins. Skeletonization also reflects chewing activity rather than internal mining.

Question 24Pest Identification and Biology

Two insects feed on the same shrub. One has piercing-sucking mouthparts and gradual metamorphosis; the other has chewing mouthparts and complete metamorphosis. Which pairing correctly matches these descriptions?

  1. Aphid and caterpillar Correct answer.
  2. Caterpillar and aphid
  3. Beetle and grasshopper
  4. Grasshopper and beetle

Explanation

Aphids are Hemiptera with piercing-sucking mouthparts and gradual metamorphosis, while caterpillars are Lepidoptera with chewing mouthparts and complete metamorphosis. Reversing the pairing misassigns both traits. Beetles and grasshoppers do not fit the first description because both have chewing mouthparts.

Question 25Pest Identification and Biology

A pest outbreak follows the introduction of an ornamental plant species that has no close relatives in the region. Which principle best explains why native natural enemies may fail to control the new pest?

  1. The pest reproduces more slowly than native species
  2. Specialist natural enemies are absent because the host is novel Correct answer.
  3. Native plants always resist introduced pests
  4. The pest cannot survive without its original host

Explanation

When a plant is introduced without its associated natural enemies, specialist predators and parasitoids that depend on the pest are often missing, allowing populations to grow unchecked. Generalist enemies may still attack but usually exert less control. This enemy-release effect is a key reason new introductions can become damaging.

Question 26Pest Identification and Biology

A nursery worker finds a plant-feeding mite on greenhouse ferns. Which body feature would confirm the pest is a spider mite rather than an insect?

  1. Two pairs of legs and a shell-like covering
  2. Four pairs of legs and a single fused body region Correct answer.
  3. Wings present and six legs in the adult stage
  4. Three pairs of legs and a clearly segmented abdomen

Explanation

Spider mites are arachnids, and adult arachnids carry four pairs of legs with the body divided into two regions rather than the three-part insect plan. Insects, by contrast, bear three pairs of legs in the adult stage and a body split into head, thorax and abdomen. Leg counts and body segmentation are therefore the quickest field characters for separating mites from insects.

Question 27Pest Identification and Biology

A client's rose bed shows buds that fail to open and are crusted with dense, sticky, sooty material, while the undersides of new shoots carry clusters of small oval insects. Which pest is most consistent with this picture?

  1. Leafhoppers
  2. Aphids Correct answer.
  3. Cutworms
  4. Slugs

Explanation

Aphids feed in dense colonies on tender new growth and excrete honeydew, a sugary liquid that coats buds and supports the growth of black sooty mould. The combination of distorted, unopened buds, sticky residue and clustered oval insects on soft shoots is characteristic. Chewing pests and mobile hoppers do not leave this honeydew signature.

Question 28Pest Identification and Biology

During scouting, a technician notes that a beetle has chewing mouthparts while a nearby bug has piercing-sucking mouthparts. Which pair of damage patterns is expected?

  1. Ragged holes from the beetle; ragged holes and missing leaf margins from the bug
  2. Skeletonized leaves from the beetle; complete defoliation from the bug
  3. Ragged holes from the beetle; pale stippling and distorted growth from the bug Correct answer.
  4. Silvery trails from the beetle; curled shoot tips from the bug

Explanation

Chewing mouthparts remove tissue, producing missing chunks, ragged edges or skeletonization. Piercing-sucking mouthparts withdraw cell contents without removing tissue, so leaves show stippling, bleaching, and distortion or curling as surviving cells expand unevenly. Matching mouthpart type to injury pattern is the basis of field diagnosis.

Question 29Pest Identification and Biology

A grower reports that a caterpillar pest on greenhouse bedding plants has been controlled with a stomach poison applied to foliage, but a related pest on the same crop is unaffected. Which pest is most likely to escape a foliar stomach poison?

  1. A mealybug feeding from within waxy, sheltered leaf axils Correct answer.
  2. A beetle chewing visible holes in outer leaves
  3. A caterpillar chewing exposed leaf margins
  4. A grasshopper consuming whole leaf blades

Explanation

Stomach poisons act only after the insect ingests treated plant tissue, so pests that feed in concealed or waxy-protected sites, or that feed by inserting mouthparts into plant tissue rather than swallowing foliage, may take in little or no active ingredient. Mealybugs feed from sheltered axils under a waxy coating and are notoriously difficult to wet with contact or stomach sprays. Exposed chewers ingest treated tissue readily and are far more vulnerable.

Question 30Pest Identification and Biology

A woody ornamental shows wilting of one branch while the rest of the crown remains healthy, and removing bark from that branch reveals a darkened, tunnelled area beneath the surface. Which conclusion is best supported?

  1. A foliar fungus has spread downward from the branch tip
  2. A sucking insect has removed sap from the leaves of the branch
  3. A root rot has advanced upward through the main trunk
  4. A wood-boring insect has disrupted the vascular tissue of that branch Correct answer.

Explanation

Localized wilting of a single branch, combined with darkened galleries under the bark, points to an insect feeding within the wood and severing the vascular pathways that supply that branch. Root or crown problems usually affect the whole plant or follow a pattern from the base upward, and foliar pathogens cause spots or blights rather than internal tunnelling. The gallery itself is direct physical evidence of a borer.

Question 31Integrated Pest Management and Decision-Making

Which statement best defines integrated pest management (IPM) in a landscape setting?

  1. A strategy that eliminates all insects from the site before planting ornamental species
  2. A decision process that combines monitoring, thresholds, and multiple control tactics to keep pest damage below an acceptable level Correct answer.
  3. A calendar-based program that applies a broad-spectrum insecticide every two weeks during the growing season
  4. A method that relies only on biological control agents and excludes cultural or chemical tools

Explanation

IPM is a decision framework, not a fixed spray schedule. It uses monitoring and thresholds to decide whether action is needed, then selects cultural, physical, biological, and chemical tactics that fit the site. The goal is acceptable pest suppression with the least risk, not total elimination.

Question 32Integrated Pest Management and Decision-Making

A scout finds an average of 12 spider mites per leaflet on a crop with a treatment threshold of 8 mites per leaflet. What is the most appropriate IPM response?

  1. Reduce irrigation to stress the plants
  2. Apply a labelled miticide or other suitable tactic now Correct answer.
  3. Stop monitoring until damage becomes visible
  4. Wait two weeks and re-check the population

Explanation

When monitoring shows the pest population has reached or exceeded the established threshold, action is justified. The threshold exists to trigger a control decision before economic or aesthetic damage becomes unacceptable. Choosing a labelled, targeted tactic is the next IPM step.

Question 33Integrated Pest Management and Decision-Making

Which practice is the clearest example of a cultural control in a landscape IPM program?

  1. Releasing purchased predatory mites onto infested shrubs
  2. Choosing disease-resistant cultivars and spacing plants for good airflow Correct answer.
  3. Setting pheromone-baited sticky traps
  4. Applying a soil drench of a systemic insecticide

Explanation

Cultural controls modify the plant, the site, or the management practices to prevent pest problems. Resistant cultivars and appropriate spacing reduce disease pressure by limiting humidity and susceptible tissue. Releases, pesticides, and traps belong to other tactic categories.

Question 34Integrated Pest Management and Decision-Making

What is the primary purpose of regular pest monitoring in an IPM program?

  1. To provide current information on pest presence, numbers, and natural enemies so control decisions are justified Correct answer.
  2. To determine the exact mixing rate of a pesticide
  3. To confirm that all pests have been eliminated from the site
  4. To satisfy record-keeping requirements after a pesticide application

Explanation

Monitoring supplies the evidence used to make decisions: which pests are present, how many, where they are, and whether natural enemies are active. Without current data, thresholds cannot be applied and treatments become guesswork. Monitoring is not primarily a compliance formality.

Question 35Integrated Pest Management and Decision-Making

Which situation best describes pesticide resistance?

  1. A pest population becomes harder to control because susceptible individuals were removed and survivors passed on heritable traits Correct answer.
  2. A sprayer nozzle becomes clogged and delivers an uneven pattern
  3. A pesticide loses potency because it was stored in a hot shed over winter
  4. A product fails because it was mixed with incompatible tank-mix partners

Explanation

Resistance is an inherited, population-level change produced by selection. Repeated use of the same mode of action favours individuals that survive and reproduce, so the population shifts toward reduced susceptibility. Storage problems, equipment faults, and tank-mix incompatibility are not resistance.

Question 36Integrated Pest Management and Decision-Making

Which approach best reflects resistance management when repeated applications of one insecticide are needed against a pest?

  1. Apply the same product more frequently at a lower rate
  2. Mix two products with the same mode of action in every tank
  3. Rotate among products with different modes of action and use non-chemical tactics where possible Correct answer.
  4. Increase the rate above the label maximum to ensure kill

Explanation

Resistance management relies on reducing selection pressure on any single mode of action. Rotating among different modes of action and integrating cultural or biological tactics slows the build-up of resistant individuals. Label rates and intervals must always be respected.

Question 37Integrated Pest Management and Decision-Making

A landscaper wants to confirm whether a wilting shrub problem is caused by an insect, a pathogen, or an abiotic factor. What is the most useful first step?

  1. Collect a representative sample and examine the plant carefully, including roots and site conditions Correct answer.
  2. Apply a broad-spectrum fungicide and observe the response
  3. Replace the shrub immediately with the same species
  4. Remove all mulch within ten metres of the plant

Explanation

Correct diagnosis must precede any treatment, because abiotic problems and pathogens are not corrected by insecticides. Careful examination of foliage, stems, roots, and site conditions, plus a representative sample, provides the evidence needed. Treating before diagnosing risks wasted or harmful applications.

Question 38Integrated Pest Management and Decision-Making

In IPM terminology, what are natural enemies?

  1. Pesticide adjuvants that improve spray coverage
  2. Organisms such as predators and parasitoids that attack and reduce pest populations Correct answer.
  3. Weeds that compete with the crop for water and nutrients
  4. Soil amendments that increase plant vigour

Explanation

Natural enemies are the living organisms that regulate pest numbers, chiefly predators, parasitoids, and pathogens. Conserving them is a core biological control strategy because they can hold pests below thresholds. They are not weeds, adjuvants, or fertilizers.

Question 39Integrated Pest Management and Decision-Making

A scout reports that aphid numbers are rising but so are lady beetle larvae and syrphid fly larvae. How should this information influence the control decision?

  1. Apply a broad-spectrum insecticide immediately to prevent any further increase
  2. Stop scouting because biological control is now guaranteed to succeed
  3. Ignore the natural enemies because only pest counts matter
  4. Consider the predator-to-pest ratio and possibly delay treatment while monitoring continues Correct answer.

Explanation

Natural enemy activity is part of the decision, because predators and parasitoids may suppress the pest without intervention. Comparing pest and enemy numbers and continuing to monitor allows time for biological control to work. Broad-spectrum sprays would kill the very organisms providing that service.

Question 40Integrated Pest Management and Decision-Making

Which of the following is a density-independent factor that can affect a pest population regardless of how many individuals are present?

  1. Crowding-induced shortage of food
  2. A late spring frost that kills exposed larvae Correct answer.
  3. Increased transmission of a pest pathogen at high density
  4. Competition for limited nesting sites

Explanation

Density-independent factors act in proportion to environmental conditions rather than population size. A frost kills exposed individuals whether the population is large or small. Competition, food shortage, and density-linked disease transmission are density-dependent because their effect changes with population size.

Question 41Integrated Pest Management and Decision-Making

A manager wants to reduce the risk of fungicide resistance in a turf disease program. Which plan is most consistent with resistance management principles?

  1. Apply only when symptoms are severe and then use the maximum rate repeatedly
  2. Use half the labelled rate more often to reduce total product
  3. Apply the same active ingredient preventively at every application for the whole season
  4. Alternate fungicides from different chemical groups and combine them with cultural practices that reduce disease pressure Correct answer.

Explanation

Alternating among different chemical groups reduces selection for resistance to any one mode of action. Combining this with cultural practices lowers disease pressure and the number of applications needed. Rate reduction or repeated use of one active ingredient increases resistance risk.

Question 42Integrated Pest Management and Decision-Making

What does an economic or aesthetic threshold represent in an IPM program?

  1. The number of traps required per hectare for reliable monitoring
  2. The maximum legal rate of a pesticide that may be applied to a site
  3. The date after which no pesticide may be applied in a season
  4. The pest density at which control action is justified to prevent unacceptable damage Correct answer.

Explanation

A threshold translates pest numbers into a decision: act when the population is likely to cause damage that outweighs the cost and risk of treatment. It is a biological and economic reference point, not a legal rate limit or a calendar date. Monitoring data are compared against it.

Question 43Integrated Pest Management and Decision-Making

A grower notices that a pesticide that once worked well now gives poor control, but the same product still performs normally on a different pest at the same site. What is the most likely explanation?

  1. The sprayer is calibrated incorrectly for all applications
  2. The weather has permanently changed at the site
  3. The target pest population has developed resistance to that product Correct answer.
  4. The product has expired and lost all activity

Explanation

Resistance develops in the population exposed to selection, so poor control on one pest while the product still works on another points to resistance rather than product failure. Expiry, calibration, and weather would affect performance more broadly. Confirming resistance may require a resistance assay or field comparison.

Question 44Integrated Pest Management and Decision-Making

Which monitoring method is most appropriate for detecting night-flying adult moths in a nursery?

  1. Soil core sampling to a depth of 30 cm
  2. Visual inspection of upper leaf surfaces at midday
  3. Counting weeds along the nursery perimeter
  4. Pheromone-baited or light traps checked regularly Correct answer.

Explanation

Traps baited with species-specific pheromones or light traps are designed to capture night-flying adults and provide an index of activity. Regular checking allows timing of scouting or control to pest flight periods. Midday visual inspection and soil cores target other life stages or organisms.

Question 45Integrated Pest Management and Decision-Making

A landscape crew finds a new invasive insect on a client's property and is unsure of its identity. What is the most appropriate action?

  1. Remove and destroy all plants within the property boundary
  2. Assume it is harmless and take no further action
  3. Apply the strongest available insecticide to eliminate it before identification
  4. Submit a specimen or clear photographs to a diagnostic laboratory or extension specialist Correct answer.

Explanation

Accurate identification is essential before any management decision, especially for a suspected invasive species. Submitting a specimen or good images to a diagnostic service provides that identification and may trigger reporting requirements. Treating or destroying plants without identification is premature.

Question 46Integrated Pest Management and Decision-Making

Which statement best explains why conserving habitat for natural enemies supports IPM?

  1. It guarantees that no pesticide will ever be required
  2. It increases the number of pest species that can colonize the site
  3. It eliminates the need for any monitoring
  4. It provides refuge, nectar, and alternate prey that sustain predators and parasitoids when pests are scarce Correct answer.

Explanation

Natural enemies need resources such as nectar, pollen, shelter, and alternate prey to persist when the target pest is scarce. Providing these resources supports biological control and can reduce pest outbreaks. It does not eliminate the need for monitoring or occasional treatment.

Question 47Integrated Pest Management and Decision-Making

A manager decides to use a spot treatment of a labelled herbicide on a few patches of an invasive weed rather than broadcasting over the whole site. Which IPM principle does this best illustrate?

  1. Treating the entire site is always the most economical choice
  2. Targeting control to where the pest is present and limiting off-target exposure Correct answer.
  3. Relying solely on chemical control for all pests
  4. Eliminating the need to identify the weed species

Explanation

Spot treatment applies control only where the pest is present, reducing total pesticide use and off-target exposure. This reflects the IPM principle of targeted, justified intervention based on monitoring. It does not remove the need for correct identification.

Question 48Integrated Pest Management and Decision-Making

A pest population is monitored over several weeks. Numbers rise steadily, then fall sharply after a period of heavy rain and high humidity. Which conclusion is most defensible?

  1. Environmental conditions, possibly favouring a pathogen, contributed to the decline Correct answer.
  2. The pest has permanently disappeared from the site
  3. The pest has developed resistance to all controls
  4. The monitoring method must be invalid

Explanation

A sharp decline coinciding with a change in weather suggests an environmental factor such as humidity favouring an entomopathogen or directly harming the pest. This is a plausible density-independent or pathogen-driven effect. It does not demonstrate resistance or prove permanent absence.

Question 49Integrated Pest Management and Decision-Making

When selecting a control tactic for a pest, which factor is most important to confirm before application?

  1. Whether the product is the cheapest available
  2. Whether the target pest, host plant, and site are all on the product label Correct answer.
  3. Whether neighbouring properties also use the same product
  4. Whether the product has been used at the site in previous years

Explanation

The label defines legal and safe use, including the target pest, the permitted site or crop, the rate, and application conditions. Using a product outside those parameters is off-label and may be illegal or ineffective. Cost and past use do not override label requirements.

Question 50Integrated Pest Management and Decision-Making

Which combination best represents a preventative IPM strategy for a new landscape planting?

  1. Delay all site preparation until pests appear
  2. Apply a broad-spectrum insecticide to the planting hole at installation
  3. Select adapted species, prepare the soil properly, and inspect nursery stock before planting Correct answer.
  4. Plant the most susceptible species and plan to spray monthly

Explanation

Preventative IPM reduces the chance of pest establishment by matching plants to the site, improving growing conditions, and excluding infested nursery stock. Healthy, well-adapted plants tolerate pests better and require fewer interventions. Routine spraying and delayed preparation increase risk.