Illinois Field Crops Pesticide
Application Q’s and A’s
What is an Integrated Pest Management (IPM) program based on? - <CORRECT ANSWER >>-
scouting for pests
- environmental information
- technology to prevent unacceptable thresholds of pest damage by most economic means
- lowest possible risk to people, property, resources and environment
What should be done if scouting detects an important pest but its numbers do not reach the
economic threshold? - <CORRECT 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? - <CORRECT ANSWER >>Economic Threshold
Factors that are considered in determining an economic injury level - <CORRECT ANSWER >>-
Number of pests or estimate of the amount of damage
- Cost of various treatment options
- expected yield
- expected grain value
Economic Injury Level - <CORRECT 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 - <CORRECT 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 - <CORRECT ANSWER >>- Cultural (rotation, fertility,
resistant varieties)
- Mechanical (pest removal)
- Biological (bacteria, predators)
- Chemical
What kind of damage is caused by corn rootworm LARVAE? - <CORRECT 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? - <CORRECT ANSWER >>Silk
Clipping (prevents pollination & causes immature kernels)
What is the most important economic insect of pest of corn in Illinois? - <CORRECT ANSWER
>>Corn Rootworm
Economic thresholds when scouting for corn rootworm beetles - <CORRECT 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? - <CORRECT 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? - <CORRECT ANSWER >>- crop debris
- winter annual weeds
- late planted
What is the recommended methods for managing black cutworms in Illinois? - <CORRECT
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? - <CORRECT 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? - <CORRECT ANSWER >>honeydew coats the
tassel and possibly the silks reducing pollination
Describe wireworms and their damage - <CORRECT 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? - <CORRECT ANSWER >>Full
grown larvae are white, C-shaped, and about one inch long
How are Japanese beetle grub species identified - <CORRECT ANSWER >>the pattern of bristle-
like setae on the end of the abdomen, called the raster pattern
Application Q’s and A’s
What is an Integrated Pest Management (IPM) program based on? - <CORRECT ANSWER >>-
scouting for pests
- environmental information
- technology to prevent unacceptable thresholds of pest damage by most economic means
- lowest possible risk to people, property, resources and environment
What should be done if scouting detects an important pest but its numbers do not reach the
economic threshold? - <CORRECT 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? - <CORRECT ANSWER >>Economic Threshold
Factors that are considered in determining an economic injury level - <CORRECT ANSWER >>-
Number of pests or estimate of the amount of damage
- Cost of various treatment options
- expected yield
- expected grain value
Economic Injury Level - <CORRECT 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 - <CORRECT 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 - <CORRECT ANSWER >>- Cultural (rotation, fertility,
resistant varieties)
- Mechanical (pest removal)
- Biological (bacteria, predators)
- Chemical
What kind of damage is caused by corn rootworm LARVAE? - <CORRECT 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? - <CORRECT ANSWER >>Silk
Clipping (prevents pollination & causes immature kernels)
What is the most important economic insect of pest of corn in Illinois? - <CORRECT ANSWER
>>Corn Rootworm
Economic thresholds when scouting for corn rootworm beetles - <CORRECT 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? - <CORRECT 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? - <CORRECT ANSWER >>- crop debris
- winter annual weeds
- late planted
What is the recommended methods for managing black cutworms in Illinois? - <CORRECT
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? - <CORRECT 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? - <CORRECT ANSWER >>honeydew coats the
tassel and possibly the silks reducing pollination
Describe wireworms and their damage - <CORRECT 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? - <CORRECT ANSWER >>Full
grown larvae are white, C-shaped, and about one inch long
How are Japanese beetle grub species identified - <CORRECT ANSWER >>the pattern of bristle-
like setae on the end of the abdomen, called the raster pattern
