ILLINOIS FIELD CROP APPLICATORS TEST 2026
FINAL PAPER SOLVED ITEMS ACCURATE
◉ What should be done if scouting detects an important pest but its
numbers do not reach the economic threshold? Answer: Do not
treat, but scout again after an appropriate time period
◉ What is the number of pests that should be controlled to prevent
economic damage from occurring? Answer: Economic Threshold
◉ Factors that are considered in determining an economic injury
level Answer: - Number of pests or estimate of the amount of
damage
- Cost of various treatment options
- expected yield
- expected grain value
◉ Economic Injury Level Answer: the number of pests where the
value of crop loss from these pests equals the cost of controlling
them
◉ examples of economic thresholds for some insect pests Answer: -
number of insects per plant
,- number of insects per trap per week
- number of weeds per foot of row
- percent of defoliation
◉ types of control measures used in IPM Answer: - Cultural
(rotation, fertility, resistant varieties)
- Mechanical (pest removal)
- Biological (bacteria, predators)
- Chemical
◉ What kind of damage is caused by corn rootworm LARVAE?
Answer: - prune and tunnel through roots
- leaves plants susceptible to disease
- disrupts nutrient flow
- reduces stability
- lodging
◉ What kind of damage is caused by corn rootworm ADULTS?
Answer: Silk Clipping (prevents pollination & causes immature
kernels)
◉ What is the most important economic insect of pest of corn in
Illinois? Answer: Corn Rootworm
,◉ Economic thresholds when scouting for corn rootworm beetles
Answer: - when silks are green
- if silks are clipped within 1/2 inch of the tip of the ear
- from late July to early August
IN SOYBEANS- 1.5 beetles per unbaited Pherocon AM trap per day
IN CONTINOUS CORN- 2 beetles per unbaited Pherocon AM trap per
day
◉ What kind of damage does black cutworm larvae do to corn
seedlings? Answer: young - chew holes in leaves
older - cut plants
◉ What types of field factors increase the potential for black
cutworm damage to develop and why? Answer: - crop debris
- winter annual weeds
- late planted
◉ What is the recommended methods for managing black cutworms
in Illinois? Answer: apply a rescue treatment when 3% or more
plants are cut
, *preventative treatments not effective*
◉ What type of damage does larval European corn borer cause?
Answer: - feed within the whorl causing "shot holes" in the leaves
- ear tunneling and stalk tunneling
◉ What type of damage does corn leaf aphid cause? Answer:
honeydew coats the tassel and possibly the silks reducing
pollination
◉ describe wireworms and their damage Answer: Appearance:
larvae are yellow to reddish-brown, hard shelled and wire like
Damage: tunnel into seeds and seedlings below soil level
◉ What do Japanese beetle grubs and other white grubs look like?
Answer: Full grown larvae are white, C-shaped, and about one inch
long
◉ How are Japanese beetle grub species identified Answer: the
pattern of bristle-like setae on the end of the abdomen, called the
raster pattern
◉ What kind of damage do Japanese beetle grubs cause? Answer: -
chew on roots and root hairs of seedlings
FINAL PAPER SOLVED ITEMS ACCURATE
◉ What should be done if scouting detects an important pest but its
numbers do not reach the economic threshold? Answer: Do not
treat, but scout again after an appropriate time period
◉ What is the number of pests that should be controlled to prevent
economic damage from occurring? Answer: Economic Threshold
◉ Factors that are considered in determining an economic injury
level Answer: - Number of pests or estimate of the amount of
damage
- Cost of various treatment options
- expected yield
- expected grain value
◉ Economic Injury Level Answer: the number of pests where the
value of crop loss from these pests equals the cost of controlling
them
◉ examples of economic thresholds for some insect pests Answer: -
number of insects per plant
,- number of insects per trap per week
- number of weeds per foot of row
- percent of defoliation
◉ types of control measures used in IPM Answer: - Cultural
(rotation, fertility, resistant varieties)
- Mechanical (pest removal)
- Biological (bacteria, predators)
- Chemical
◉ What kind of damage is caused by corn rootworm LARVAE?
Answer: - prune and tunnel through roots
- leaves plants susceptible to disease
- disrupts nutrient flow
- reduces stability
- lodging
◉ What kind of damage is caused by corn rootworm ADULTS?
Answer: Silk Clipping (prevents pollination & causes immature
kernels)
◉ What is the most important economic insect of pest of corn in
Illinois? Answer: Corn Rootworm
,◉ Economic thresholds when scouting for corn rootworm beetles
Answer: - when silks are green
- if silks are clipped within 1/2 inch of the tip of the ear
- from late July to early August
IN SOYBEANS- 1.5 beetles per unbaited Pherocon AM trap per day
IN CONTINOUS CORN- 2 beetles per unbaited Pherocon AM trap per
day
◉ What kind of damage does black cutworm larvae do to corn
seedlings? Answer: young - chew holes in leaves
older - cut plants
◉ What types of field factors increase the potential for black
cutworm damage to develop and why? Answer: - crop debris
- winter annual weeds
- late planted
◉ What is the recommended methods for managing black cutworms
in Illinois? Answer: apply a rescue treatment when 3% or more
plants are cut
, *preventative treatments not effective*
◉ What type of damage does larval European corn borer cause?
Answer: - feed within the whorl causing "shot holes" in the leaves
- ear tunneling and stalk tunneling
◉ What type of damage does corn leaf aphid cause? Answer:
honeydew coats the tassel and possibly the silks reducing
pollination
◉ describe wireworms and their damage Answer: Appearance:
larvae are yellow to reddish-brown, hard shelled and wire like
Damage: tunnel into seeds and seedlings below soil level
◉ What do Japanese beetle grubs and other white grubs look like?
Answer: Full grown larvae are white, C-shaped, and about one inch
long
◉ How are Japanese beetle grub species identified Answer: the
pattern of bristle-like setae on the end of the abdomen, called the
raster pattern
◉ What kind of damage do Japanese beetle grubs cause? Answer: -
chew on roots and root hairs of seedlings
