Garden Insect Control Guide
E-331 (Revised), Reviewed December 1996
Dean K. McBride, Extension Entomologist
Colorado potato beetle or potato bug (21KB color photo) |
 Flea beetle (10KB color photo) |
Colorado potato beetle or potato bug larva (17KB color photo) |
 Flea beetle (18KB color photo) |
 Potato leafhopper (21KB color photo) |
 Thrips (15KB color photo) |
 Differential
grasshopper (11KB color photo) |
 Webworm (14KB color photo) |
 Cabbage
looper or inchworm (11KB color photo) |
 Cutworm (27KB color photo) |
 European corn borer (18KB color photo) |
 Wireworm (13KB color photo) |
Cucumber beetle (4KB b&w illustration) |
 Potato flea beetle (4KB
b&w illustration) |
This bulletin is intended for use in providing helpful information for the control of garden insect pests. Use chemical control only when necessary and always read the label on the package before applying the product.
| Pest | Crops | Insecticide To Use and Rates of Application* | Remarks |
| Aphids | Cabbage, corn, cucumbers, melons | Malathion: 2 tsps. 57% emulsifiable concentrate | Observe a 3-7 day waiting period depending on vegetable. |
| Diazinon (Spectracide): Several formulations. Follow label directions. | Up to 7 days waiting period on some vegetables, see label instructions. | ||
| Asparagus Beetle | Asparagus | Malathion: 2 tsps. 57% emulsifiable concentrate | One day waiting period. |
| Carbaryl (Sevin): 2 Tbls. 50% wettable powder | One day waiting period. | ||
| Cucumber Beetles | Melons, cucumbers, squash. (These vegetables are easily injured by most insecticides; therefore, apply light application only.) | Methoxychlor: 2 Tbis. 50% wettable powder | Seven day waiting period. |
| Diazinon (Spectracide): Several formulations Follow label directions. | Up to 7 days waiting period on some vegetables, see label instructions. | ||
| Carbaryl (Sevin): 2 Tbls. 50% wettable powder | One day waiting period. | ||
| Colorado Potato Beetle & Flea Beetle | Potatoes | Methoxychlor: 2 Tbls. 50% wettable powder | Treat for Colorado potato beetle as soon as brick colored larvae appear. Seven day waiting period. No waiting period. |
| Carbaryl (Sevin): 1 Tbls. 50% wettable powder | |||
| Diazinon (Spectracide): Several formulations. Follow label directions. | Thirty-five day waiting period. | ||
| European Corn Borer | Corn, tomato, potato and peppers | Carbaryl (Sevin): 3 Tbls. 50% wettable powder | Make first application when 50 or more egg clusters are found per 100 plants. Egg masses are found on underside of leaves. Use 1-1/2 gals. of spray per 100 plants. Repeat treatment 3 times at 5 day intervals beginning about July 4. |
| Bacillus thuringiensis (Dipel, Biotrol, Thuricide) | Apply according to label instructions. | ||
| Flea Beetle | Tomatoes, potatoes, radishes | Carbaryl (Sevin): 1 Tbls. 50% wettable powder | Waiting period is 3 days. |
| Methoxychlor: 2 Tbls. 50% wettable powder | Waiting period is 7 days. | ||
| Diazinon (Spectracide): Several formulations Follow label directions | Waiting periods: Tomatoes - 1 day Potatoes - 35 days Radishes - 10 days |
||
| Corn Ear Worm | Corn | Carbaryl (Sevin): 3 Tbls. 50% wettable powder | If control is necessary, mix 3 Tbls. carbaryl (Sevin) 50% wettable powder per gallon of water. Direct sprays at ear zone and silks every 4 days during silking until silks dry up. |
| Bacillus thuringiensis (Dipel, Biotrol, Thuricide) | Apply according to label instructions. | ||
| Grasshopper | General feeders | Carbaryl (Sevin): 3 Tbls. 50% wettable powder | May be used within 3 days of harvest. |
| Malathion: 2 tsps. 57% emulsifiable concentrate | May be applied to vegetables within 3 days of harvest. | ||
| Diazinon (Spectracide): Several formulations Follow label directions | Up to 10 days waiting period on some vegetables; see label instructions. | ||
| Leafhoppers | General feeders | Malathion: 2 tsps. 25% wettable powder or 2 tsps. 57% emulsifiable concentrate. | Wait at least 4-7 days before harvesting. |
| Carbaryl (Sevin): 3 Tbls. 50% wettable powder | May be used within 3 days of harvest. | ||
| Methoxychlor: 2 Tbls. 50% wettable powder | Seven day waiting period. | ||
| Diazinon: 2 tsps. 25% emulsifiable concentrate | Up to 10 days waiting period on some vegetables see label instructions. | ||
| Cabbage Looper & Cabbage Worm | Cabbage and related crops | Malathion: 2 tsps. 57% emulsifiable concentrate | Seven day waiting period. Wait 14 days for leafy vegetables. |
| Carbaryl (Sevin): 3 Tbls 50% wettable powder | May be used within 3 days of harvest. | ||
| Bacillus thuringiensis (Dipel, Biotrol, Thuricide) | Apply according to label instructions. No waiting period. | ||
| Diazinon (Spectracide): Several formulations Follow label instructions | Seven day waiting period. | ||
| Onion Thrips | Onions | Diazinon (Spectracide): Several formulations Follow label directions | Spray every 10-14 days as needed. Wait 10 days to harvest |
| Malathion: 2 tsps. 57% emulsifiable concentrate | Repeat application every 7-10 days. Three day waiting period. | ||
| Mites (Red Spider) | Before treatment, check the label of the pesticide you intend to use to be sure that it is registered for the vegetable you want to treat as mites will attack various vegetables. | Malathion: 2 tsps. 57% emulsifiable concentrate | Waiting period varies depending upon vegetable treated. |
| Diazinon (Spectracide): Several formulations Follow label directions | Waiting period varies depending upon vegetable treated. | ||
| Hornworm | Tomatoes | Carbaryl (Sevin): 2 Tbls. 50% wettable powder | One day waiting period. |
| Bacillus thuringiensis (Dinel. Biotrol. Thuricide) | Use according to label instructions. | ||
*Rates of application for dusts are to 50 feet of garden row Rates of
application for wettable powders and emulsifiable concentrates are for 1 gallon of water.
Soil Treatments for Garden Pests
| Pest | Crops | Insecticide To Use & Rates of Application* |
Remarks |
| Cutworms | General feeders | Carbaryl (Sevin): 5% bait (as directed). Sevin 50% wettable powder at 3-4 Tbls. per gal. water. | If cutworms appear after planting, apply insecticide to soil surface around plants. |
| Diazinon (Spectracide): Several formulations Follow the label | Use as preplant broadcast, work into upper 3-4 inches of soil for surface cutworms - 3-6 inches for subterranean cutworms. | ||
| Bacillus thuringiensis (Dipel, Biotrol, Thuricide) | Apply according to label instructions. | ||
| Cabbage or Onion Maggot | Cabbage or onion | Diazinon (Spectracide): Several formulations | Apply as a preplant broadcast treatment and work into the of soil. top 3-4 inches |
| White Grubs, Wireworms | General feeders | Diazinon (Spectracide): Several formulations Follow the label | Apply broadcast just before planting. Immediately work into soil 4-8 inches. Waiting period varies depending upon vegetable treated. |
| Slugs** | General feeders | Metaldehyde 4% liquid bait | Apply a iine of drops 3-4 inches apart on soil between vegetable plants. Do not apply directly onto plants. |
| Metaldehyde 3.25% dry pellet bait: 1 lb. per 1,000 sq. ft. | Water lightly after application. Do not contaminate edible plant parts. | ||
| Stale beer | Bury pans near dense vegetation so that top of the rim is flush with soil surface. Fill pans to rim level with beer. Remove slugs frequently. | ||
*Rates of application for dusts are to 50 feet of garden row Rates of
application for wettable powders and emulsifiable concentrates are for 1 gallon of water.
**Avoid watering garden daily, allow the surface to dry between waterings. The removal of
excess plant debris, stones, etc. aids in eliminating hiding places for slugs.
Be A Competent Applicator of Pesticides
- Read and understand pesticide labels and labeling.
- Recognize common pests and the damages they cause.
- Apply pesticides according to label instructions.
- Recognize environmentally hazardous situations to avoid.
- Recognize poisoning symptoms.
To become a certified pesticide applicator contact your county agent.
E-331, Revised, Reviewed December 1996
