Aphids gather on a Jerusalem artichoke plant. Attribution: Benny Mazur (Flickr) http://www.flickr.com/photos/benimoto/2712790382/
They buzz, fly, jump, creep, and crawl in and around our home gardens. Most gardeners learn to quickly identify and control insect pests like aphids and cutworms, but this doesn’t make them any less of a nuisance. These “bad” bugs can cause significant damage to trees, shrubs, flowers, plants, and crops, and they can be highly difficult to control. Here we bring you the worst insect invaders and how you rid them from your garden.
1. Aphids
Measuring only a tenth of an inch long, sap-sucking aphids can weaken vegetation and spread disease from plant to plant. For a small infestation, a blast of water or a spray of insecticidal soap is usually enough to kill off these pests. The introduction of “good” bugs, such as ladybugs, can also clean up an aphid infestation quickly.
2. White Flies
Clusters of white flies can commonly be found on the underside of leaves. These tiny winged insects closely resemble aphids and ingest plant juices. When plant juice is ingested, white flies excrete a sticky substance known as honeydew, which can cause fungal diseases to form on leaves. Get rid of white flies with the use of white fly traps or an insecticidal soap spray. Spiders and ladybugs can also help with a white fly population.
3. Cabbage Worms
Cabbage worms prey on various members of the cabbage vegetable family, including cauliflower, kale, and broccoli. Damage done to these crops during seedling establishment or early head formation can affect both growth and yield. Keep these pests away by covering the plants with row covers, spraying with BTK (Bacillus thuringiensis var. kurstaki) every one to two weeks, and introducing “good” insects like trichogramma wasps.
4. Flea Beetles
Small, shiny flea beetles pose a threat to newly emerging plants, producing “shootholes” in the leaves and spreading bacterial diseases, such as wilt and blight. Flea beetles typically cause the most harm early in the planting season when the weather reaches 50 degrees. Delay the planting or transplanting process by a couple weeks in the early spring to cut off their food supply.
5. Caterpillars
Caterpillars are the larvae of butterflies and moths and are regarded as voracious eaters. To gain enough energy for transformation, these garden pests must consume large amounts of plant material, stripping plants of their leaves. If the insects are few and far between, simply pick them off and relocate them to a different area. Spray the foliage of plants with neem oil, which controls caterpillars and other pests.
6. Fire Ants
While most species are neutral and some even beneficial, certain species like the red imported fire ant (Solenopsis invicta) can wreak havoc on your garden. These pests can devour germinating speeds, tunnel into tomatoes and potatoes, and will bite and sting upon contact. Control fire ants by using a fire ant bait product containing spinosad, a natural metabolite, one to two times per year.
7. Bean Leaf Beetle
Colorful bean leaf beetles measure approximately ¼ inch long and prefer to snack on snap beans, soybeans, dry edible beans, clover, and various leguminous weeds. They feed primarily on the undersides of leaves, creating 1/8-inch holes. Bean leaf beetles can be handpicked from your garden and dropped into a pail of soapy water. For larger infestations, insecticides may be needed.
8. Spider Mites
Spider mites are commonly found indoors and out, but their presence is usually not recognized until plant damage occurs. These teeny-tiny pests congregate on the underside of leaves and sip on plant fluids. Dislodge and kill off spider mites with a high-pressure stream of water from the hose or with a wet sponge wiped on the leaves. Remove any heavily infested leaves and discard them in a sealed plastic bag. Ward off new insects by spraying a soap solution directly on the foliage.
9. Tarnished Plant Bugs
Tarnished plant bugs feed on vegetable plants as well as strawberries and other soft fruits. These pests will suck sap from flower buds and young foliage, causing leaves to become distorted and buds to never open. Since tarnished plant bugs tend to hide, keep plant litter and weeds cleared away. Spray the plants with insecticidal soap every couple of weeks.
10. Tomato Hornworm
Tomato hornworms are common in most regions in the United States and are attracted to crops like tomatoes, eggplant, potatoes, and peppers. These green caterpillar pests blend in with green foliage and are always eating, leaving chewed leaves and fruit. To rid your garden of these pests, till the soil at the beginning and end of the gardening season to destroy larvae. Wasps are considered “good” insects and feed on hornworms.
11. Scales
Scale insects are parasitic pests that adhere to plants and gain nourishment from their sap. Treat scales with dormant oil in the late spring, just before the plant leaves unfurl. If caught early enough, the infected branches can also be pruned. If you continue to have problems, introduce other insects that prey on scales, such as lady beetles, soldier beetles, and parasitic wasps.
Aphids, cabbage worms and caterpillars – among others – are considered some of the most vile pests around, damaging plants and entire gardens. What garden pests do you consider the worst? And what solutions have you found to conquer these creepy critters?