| Insect parts | Head, thorax, abdomen |
| Gradual metamorphosis | Grasshoppers, cockroaches, aphids. Go through several instars. Insect that hatches from the egg looks like a small adult. |
| Complete metamorphosis | Egg, 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 Level | Density of the pest population where the cost of control equals the crop loss due to pests. |
| Economic threshold | Density 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 control | Crop rotation, adjusting planting/harvest date |
| Example of mechanical control | Shredding 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 control | Predators, 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 treatments | No 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 spring | Deeper, 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 options | Prevention/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 larger | Grass, corn |
