ILLINOIS FIELD CROP APPLICATORS TEST 2026
PREMIUM REVIEW QUESTIONS CORRECT
RESPONSES
◉ describe soybean aphids and where they occur Answer: pinhead-
sized, yellow, soft bodied, round insects on the underside of soybean
leaves
◉ what kind of damage do soybean aphids cause? Answer: - they
suck sap from soybean plants causing leaves to crinkle or cup and
turn yellow
- they excrete honeydew, a sugary substance consisting of excess
plant sap taken up by the aphid while feeding
- sooty mold, a blackish mold that grows on the honeydew, reducing
photosynthesis
-heavy infestations may cause a reduction in the number of pods
- they are capable of transmitting several viruses
◉ what kind of damage do spider mites cause to soybean plants
Answer: - stippling leaves
- fine silk on leaves and between plants
- bronzing leaves
- curled leaves and leaf drop
,◉ Describe the appearance of alfalfa weevil LARVAE? Answer: -up to
1/2" long
- green with white stripe down back
- dark head
◉ Describe the appearance of alfalfa weevil ADULT? Answer: - 1/4"
long
- medium brown with dark brown stripe
- hard wing covers
◉ What kind of damage does alfalfa weevil cause? Answer: - larvae
skeletonize leaves, causing fields to appear "frosted"
- adults "feather" the leaves and chew on stems
Economic Thresholds:
-at first cutting: >3 larvae per stem and 20% of the tips skeletonized
-later cuttings: feeding on 50% of crowns and no regrowth for 3-6
days
◉ describe the appearance of potato leafhopper Answer: green
wedge shaped about 1/8 inch long
, ◉ what kind of damage does potato leafhopper cause? Answer: -
yellowish leaflets
- dark brown triangular leaflet tips
- suck fluids from leaves
◉ when is alfalfa most suceptible to potato leafhopper damage, and
as a consequence, when is scouting for this pest most critical?
Answer: right after cutting
◉ Describe the appearance of older armyworm larvae Answer: -
green/brown with orange stripes
- up to 1 1/2" long
◉ What kind of damage do armyworms cause to wheat Answer: -
feed on leaf edges
- chew through wheat stems, causing heads to fall off
◉ Economic Thresholds for grasshoppers Answer: Non-crop Areas:
15-20 nymphs per square yard
Corn: > 7 per square yard
Soybean: 5-10% pod feeding
◉ List the types of leaf sheaths used to identify grass weed seedlings
Answer: - closed or split
PREMIUM REVIEW QUESTIONS CORRECT
RESPONSES
◉ describe soybean aphids and where they occur Answer: pinhead-
sized, yellow, soft bodied, round insects on the underside of soybean
leaves
◉ what kind of damage do soybean aphids cause? Answer: - they
suck sap from soybean plants causing leaves to crinkle or cup and
turn yellow
- they excrete honeydew, a sugary substance consisting of excess
plant sap taken up by the aphid while feeding
- sooty mold, a blackish mold that grows on the honeydew, reducing
photosynthesis
-heavy infestations may cause a reduction in the number of pods
- they are capable of transmitting several viruses
◉ what kind of damage do spider mites cause to soybean plants
Answer: - stippling leaves
- fine silk on leaves and between plants
- bronzing leaves
- curled leaves and leaf drop
,◉ Describe the appearance of alfalfa weevil LARVAE? Answer: -up to
1/2" long
- green with white stripe down back
- dark head
◉ Describe the appearance of alfalfa weevil ADULT? Answer: - 1/4"
long
- medium brown with dark brown stripe
- hard wing covers
◉ What kind of damage does alfalfa weevil cause? Answer: - larvae
skeletonize leaves, causing fields to appear "frosted"
- adults "feather" the leaves and chew on stems
Economic Thresholds:
-at first cutting: >3 larvae per stem and 20% of the tips skeletonized
-later cuttings: feeding on 50% of crowns and no regrowth for 3-6
days
◉ describe the appearance of potato leafhopper Answer: green
wedge shaped about 1/8 inch long
, ◉ what kind of damage does potato leafhopper cause? Answer: -
yellowish leaflets
- dark brown triangular leaflet tips
- suck fluids from leaves
◉ when is alfalfa most suceptible to potato leafhopper damage, and
as a consequence, when is scouting for this pest most critical?
Answer: right after cutting
◉ Describe the appearance of older armyworm larvae Answer: -
green/brown with orange stripes
- up to 1 1/2" long
◉ What kind of damage do armyworms cause to wheat Answer: -
feed on leaf edges
- chew through wheat stems, causing heads to fall off
◉ Economic Thresholds for grasshoppers Answer: Non-crop Areas:
15-20 nymphs per square yard
Corn: > 7 per square yard
Soybean: 5-10% pod feeding
◉ List the types of leaf sheaths used to identify grass weed seedlings
Answer: - closed or split
