Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: Level 1

Questions and Answers List

level questions: Level 1

QuestionAnswer
Insect partsHead, thorax, abdomen
Gradual metamorphosisGrasshoppers, cockroaches, aphids. Go through several instars. Insect that hatches from the egg looks like a small adult.
Complete metamorphosisEgg, larvae, pupae, adult. Juveniles look nothing like the adults. Black cutworm, European corn borer, corn rootworm.
Scouting depends on two important factors:Time of day & temperature
Economic Injury LevelDensity of the pest population where the cost of control equals the crop loss due to pests.
Economic thresholdDensity of insects that justify control to prevent population from reaching EIL
If ETs are not established?Nominal thresholds are used (best judgment of specialists with experience).
Example of cultural controlCrop rotation, adjusting planting/harvest date
Example of mechanical controlShredding corn stalks to prevent European corn borer from overwintering
Example of resistant variety control?Biotechnology (Bt corn)
Insect resistant management (IRM) includes what crops?Refuge crops
What percentage of a field needs to be refuge crops?20%
Example of biological controlPredators, parasites, parasitoids, pathogens
Examples of chemical control?Emulsifiable Concentrates, Wettable Powders, Granular. Most are contact killers.
Which are safer on bees, ECs or WPs?ECs
Which is safer on honeybees, ground or aerial application?Ground
To avoid killing bees, apply before _ and after _?7 AM and 7 PM
Between _ and _, you cannot apply insecticides toxic to bees on blooming crops.8 AM and 6 PM
How far away must you stay from apiaries?1 mile
To avoid excessive residues, _ are set in units of _Tolerances, ppm
What is phytotoxicity?Injury to plants due to chemicals.
When mixing, how can you avoid phytotoxicity?Do not tank mix insecticides that are not labeled, and do not tank mix with products that are not labeled.
Which groups of insecticides are extremely toxic?Organophosphates and carbamates
What is this?Seed corn maggot
Seed corn maggot - Larvae develop in how many days?7-10
Seed corn maggot life cycle?4-8 weeks
When do seed corn maggots do the most damage?In a cool, wet spring when corn emergence is slow
Seed corn maggot - What to do if corn plants don't emerge?Dig down and look for feeding
Seed corn maggot treatmentsNo rescue treatments. Seed treatments, in-furrow insecticides.
What is this?Wireworm
Corn pest - What do wireworms become as adults?Click beetles
Corn pest - When are wireworm eggs laid?May - September
Corn pest - How long is a wireworm life cycle?Larvae occupy soil for 1-6 years, but entire life cycle can be 1-7.
Corn pest - Wireworm activity is highest in the spring in what area of the soil?Top 6 inches
Corn pest - Wireworm scouting includes 1:1 corn:wheat traps. What is the threshold that justifies treatment?1 wireworm per trap
Corn pest - Treatment options for wireworms?No rescue treatments. Seed treatments, in-furrow insecticides, or planter insecticides.
Corn pest - What is this?White grub
Corn pest - What two kinds of white grubs are there?True white grub and annual white grub
Which white grub rarely causes economic injury, the true white grub or the annual white grub?Annual white grub
How do you tell the difference between a true white grub and an annual white grub?True white grubs have a "zipper" of hair on their rasters (end of abdomen). Annual white grubs do not have any patterns of hair.
White type of grub causes economic injury, the true white or the annual white grub?True white grub
Annual white grubs become what kind of adult beetle?Masked chafers
True white grubs become which beetle as adults?June bug
True white grub life cycle?3 years
Annual white grub life cycle?1 year
Grubs move _ in the soil in the fall and move _ in the soil to feed in the springDeeper, shallower
When does true white grub cause the most damage?When soils are cooler in May and early June
True white grub treatments?No rescue treatments. Soil insecticides in-furrow, seed treatments, planter box seed treatments.
What kind of corn pest is this?Black cutworm (top) and dingy cutworm (bottom)
How do you tell black cutworms and dingy cutworms apart?Black cutworm: One pair of tubercles is smaller than the other Ding cutworm: Both pairs of tubercles are the same size
When do cutworms emerge to feed?At night
Which cutworm overwinters in Iowa?Dingy cutworms, as partially-grown larvae
Which cutworm migrates into Iowa in the spring as moths?Black cutworms
How many generations of black cutworms cause problems?Only the first
How do black cutworms damage corn?Will cut the young corn down. They feed on seedling plants and tissue
How do dingy cutworms damage corn?Climb plants and feed on leaf tissue. Will rarely cut plants down.
When to treat black cutworms?If at least 8 moths are trapped on 2 consecutive nights by ISU trapping projects, cutworms could cause injury. Check ISU predicted cutting dates.
How to scout for black cutworms?Scout 20 plants in a row, before cutting date, before V5.
When to treat dingy cutworms?Only when damage is excessive and growing conditions are bad
When do you treat cutworms when larvae are less than 3/4 inch?When 2-3% of plants are wilted or cut
When do you treat cutworms if they are ~ 1 inch in length?When 5% of plants are wilted and cut
Cutworm treatment optionsPrevention/reactive insecticides. Bt corn works on black cutworms.
When are planting time treatments justified for treating black cutworms?Only when there are several perennial problems
What is this corn pest?Grape colaspis
Grape colaspis adults emerge when?Late June - early July
When do grape colaspis adults emerge to feed on corn root hairs?Spring
What are symptoms of grape colaspis injury?Stunting, wilting, purpling, browning of leaf tips and edges
How many generations of grape colaspis beetles?Only one
What are the grape colaspis thresholds?No thresholds established
Management options for grape colaspis?No rescue treatments. Soil in-furrow insecticides, seed treatments if necessary.
What is this corn pest?Common stalk borer
Common stalk borers burrow into _ when small, and then move to _ when they are largerGrass, corn