PCA NEMATODES EXAM NEWEST WITH COMPLETE 200 QUESTIONS
AND CORRECT DETAILED ANSWERS| BRAND NEW VERSION 2026
1. Describe the relative size of plant feeding nematodes. Great variability. Range
from 0.25 um to 12 mm in length.
2. Name five to six life stages of plant-parasitic nematodes. Egg, juvenile 1, J2,
J3, J4, adult
3. Shape and size of root-knot nematode Females are round and lose their
vermiform shape as adults, males retain vermiform shape
4. Shape and size of cyst nematode Adult female is swollen, eggs retained inside
of cyst and cyst is left behind after female dies
5. Shape and size of lesion nematode Small, needle-like
6. Describe how nematode shape affects the choice of extraction method. Larger
nematodes that are swollen may be observed on the root system, but smaller
nematodes require actual extraction.
7. Identify the nematode associated with the bacterial canker pathogen of stone
fruit trees in California. Mesocriconema sp. (Ring nematode)
8. Describe the role of weed control in rotation programs for nematode pest
management. Weeds are potential hosts for many damaging nematodes, so
management of weeds is important because the program's success depends on
the absence of host roots to prevent nematode reproduction and feeding.
9. List the preferred extraction method for cyst nematodes. Sugar flotation and
centrifugation, Baermann funnel
10. Nematode groups likely associated with sugarbeets. Sugarbeet cyst, root-
knot
11. Describe the impact of biotypes or host races on nematode control. One has
to be aware of nematode biotypes present and whether control methods to a
nonhost will be effective
,12. List the factors to take into account when using quantitative assays to
forecast future nematode damage. Numerous soil, plant, management and
ecological factors
13. Describe the damage symptoms associated with cyst nematode and root-
knot nematode on sugarbeets. Cyst: root proliferation, stunted top growth,
discolored leaves; Root-knot: secondary rot infection, stunting of top growth,
discolored leaves, some root proliferation
14. Hemicycliophora arenaria management. Preplant nematicides. Hot water
treatment. Mortality associated with irrigation. Resistant crops and rootstocks.
15. Describe how nematode populations fluctuate throughout the year on an
established perennial crop. Nematode populations will fluctuate with the timing
of crop and location fluctuations. This makes year-to-year sampling critical to
sample at the same time each year.
16. List the preferred extraction method for dagger nematodes. Baermann
funnel, Sugar flotation and Centrifugation
17. Describe the plant damage symptoms caused by foliar nematodes on
ornamental and strawberry plants. Killing of either a flower or leaf bud, a
growing point that produces a blind plant, distorted, crinkled, or twisted stems
and foliage, discoloration in interveinal regions, malformed strawberries
18. Describe the impact of solarization on nematodes. Solarization may have
some success against some nematodes, but nematodes may be so deep that it is
not effective.
19. Describe how to collect field samples for trees and vineyards. Collect soil
samples near drip lines.
20. Describe how to take a sample in nursery stock. Taking cores from a series of
pots and bulking into a composite sample. Amount of cores taken depends on
the potential for loss.
, 21. List the resources available to help PCAs determine what nematodes affect a
given crop. UC IPM guidelines, California Nematode Host Associations,
NEMAPLEX, lab tests
22. List two groups of nematodes by common name that exhibit sexual
dimorphism. Cyst and root-knot nematodes
23. Identify the appropriate time of sampling for vineyards or orchards. Same
time every year
24. Define damage threshold. Level at which the pest is expected to damage the
crop
25. Nematode groups likely associated with tomato. Root-knot
26. Ditylenchus spp. management. Systemic insecticides (not in CA). Resistant
alfalfa, fenamiphos and oxamyl for garlic.
27. List common field symptoms of nematode damage in annual plantings.
Wilting plants, restricted root system.
28. Identify the major distribution determinant of cyst nematodes. Areas of host
production, such as sugarbeet
29. Aphelenchoides spp. damage symptoms. Blotches. Necrotic lesions between
veins. Malformed leaves with crinkled edges.
30. List two ways that irrigation practices can influence nematode patterns.
Irrigation may spread nematodes throughout a field and reactivate some
surviving nematodes. Lack of irrigation could dry out some nematodes.
31. Compare/contrast the use of fumigants vs nonfumigants. Fumigants are
more effective because of the ability to move throughout the soil profile, but are
also volatile and dangerous
32. Describe how initial introduction site influences distribution of some
nematode species within the field. Eggs introduced by equipment, water,
animals, wind, etc., will lead to a higher distribution in the field.
AND CORRECT DETAILED ANSWERS| BRAND NEW VERSION 2026
1. Describe the relative size of plant feeding nematodes. Great variability. Range
from 0.25 um to 12 mm in length.
2. Name five to six life stages of plant-parasitic nematodes. Egg, juvenile 1, J2,
J3, J4, adult
3. Shape and size of root-knot nematode Females are round and lose their
vermiform shape as adults, males retain vermiform shape
4. Shape and size of cyst nematode Adult female is swollen, eggs retained inside
of cyst and cyst is left behind after female dies
5. Shape and size of lesion nematode Small, needle-like
6. Describe how nematode shape affects the choice of extraction method. Larger
nematodes that are swollen may be observed on the root system, but smaller
nematodes require actual extraction.
7. Identify the nematode associated with the bacterial canker pathogen of stone
fruit trees in California. Mesocriconema sp. (Ring nematode)
8. Describe the role of weed control in rotation programs for nematode pest
management. Weeds are potential hosts for many damaging nematodes, so
management of weeds is important because the program's success depends on
the absence of host roots to prevent nematode reproduction and feeding.
9. List the preferred extraction method for cyst nematodes. Sugar flotation and
centrifugation, Baermann funnel
10. Nematode groups likely associated with sugarbeets. Sugarbeet cyst, root-
knot
11. Describe the impact of biotypes or host races on nematode control. One has
to be aware of nematode biotypes present and whether control methods to a
nonhost will be effective
,12. List the factors to take into account when using quantitative assays to
forecast future nematode damage. Numerous soil, plant, management and
ecological factors
13. Describe the damage symptoms associated with cyst nematode and root-
knot nematode on sugarbeets. Cyst: root proliferation, stunted top growth,
discolored leaves; Root-knot: secondary rot infection, stunting of top growth,
discolored leaves, some root proliferation
14. Hemicycliophora arenaria management. Preplant nematicides. Hot water
treatment. Mortality associated with irrigation. Resistant crops and rootstocks.
15. Describe how nematode populations fluctuate throughout the year on an
established perennial crop. Nematode populations will fluctuate with the timing
of crop and location fluctuations. This makes year-to-year sampling critical to
sample at the same time each year.
16. List the preferred extraction method for dagger nematodes. Baermann
funnel, Sugar flotation and Centrifugation
17. Describe the plant damage symptoms caused by foliar nematodes on
ornamental and strawberry plants. Killing of either a flower or leaf bud, a
growing point that produces a blind plant, distorted, crinkled, or twisted stems
and foliage, discoloration in interveinal regions, malformed strawberries
18. Describe the impact of solarization on nematodes. Solarization may have
some success against some nematodes, but nematodes may be so deep that it is
not effective.
19. Describe how to collect field samples for trees and vineyards. Collect soil
samples near drip lines.
20. Describe how to take a sample in nursery stock. Taking cores from a series of
pots and bulking into a composite sample. Amount of cores taken depends on
the potential for loss.
, 21. List the resources available to help PCAs determine what nematodes affect a
given crop. UC IPM guidelines, California Nematode Host Associations,
NEMAPLEX, lab tests
22. List two groups of nematodes by common name that exhibit sexual
dimorphism. Cyst and root-knot nematodes
23. Identify the appropriate time of sampling for vineyards or orchards. Same
time every year
24. Define damage threshold. Level at which the pest is expected to damage the
crop
25. Nematode groups likely associated with tomato. Root-knot
26. Ditylenchus spp. management. Systemic insecticides (not in CA). Resistant
alfalfa, fenamiphos and oxamyl for garlic.
27. List common field symptoms of nematode damage in annual plantings.
Wilting plants, restricted root system.
28. Identify the major distribution determinant of cyst nematodes. Areas of host
production, such as sugarbeet
29. Aphelenchoides spp. damage symptoms. Blotches. Necrotic lesions between
veins. Malformed leaves with crinkled edges.
30. List two ways that irrigation practices can influence nematode patterns.
Irrigation may spread nematodes throughout a field and reactivate some
surviving nematodes. Lack of irrigation could dry out some nematodes.
31. Compare/contrast the use of fumigants vs nonfumigants. Fumigants are
more effective because of the ability to move throughout the soil profile, but are
also volatile and dangerous
32. Describe how initial introduction site influences distribution of some
nematode species within the field. Eggs introduced by equipment, water,
animals, wind, etc., will lead to a higher distribution in the field.
