How to Kill Root Aphids
When it comes to gardening, insects can be your worst nightmare. Insects like the various root aphids species (family Phylloxera according to Organic Pest Control) leach nutrition and moisture from your plants by attacking their roots, leaving plants yellowed and unhealthy in otherwise ideal conditions. Controlling root aphids can revive withered plants affected by the insects. If root aphids are prevented or eliminated before they damage roots, your plants will stay heartier and healthier.
Identifying and Treating Root Aphids
Relatives of the more visible leaf aphids (Hemiptera according to Missouri Botanical Garden), root aphids are white to light green in color, but you may not notice the actual bugs. Instead, you may notice the white, powdery, waxlike substance they leave behind on your plant's roots. Root aphids do not only attack outdoor plants and crops, but also can be indoor plants' pests. If you don't want to destroy your infested indoor plants, you can bake the soil in the oven or use black plastic over the soil to raise the soil temperature high enough to kill root aphids.
Outside, using broad spectrum insecticides adversely impacts beneficial insect population so those chemicals are not recommended for use against aphids according to University of California Agriculture and Natural Resources. Instead, beneficial nematodes, tiny parasitic worms that infect many soil-dwelling insects like root aphids, are a natural way to control garden pests without harming earthworms, ladybugs and other beneficial species, according to Garden Insects, and without creating a toxic environment for you and your family.
Pyrethrum-based sprays, although best used early during an infestation, also provides an environmentally safer treatment for root aphids. Although pyrethrum is not toxic to animals or people, it can produce skin irritation in sensitive or allergic people or animals. Keep children and animals away from treated plants for 24 hours after application to minimize this risk. Like any other chemical, natural or synthetic, be sure to follow all directions and precautions.
Root Aphid Treatment: Beneficial Nematodes
1. Prepare the Nematode Solution
Fill a spray bottle with water and the appropriate amount of nematodes, according to the package instructions. Shake the bottle lightly to mix. You can buy nematodes at garden centers. These all-natural biological agents kill root aphids within a few days and are completely harmless to earthworms, plants, animals and people.
2. Prepare the Soil
Water the soil around the plant you intend to treat with nematodes so the soil is moist.
3. Spray the Soil
Spray the nematode mixture onto the soil around the root aphid-infested plant until the ground is wet. The nematodes will begin to penetrate the soil and start killing the root aphids in 24 to 72 hours. There is no need to wait to water your plants after application. The nematodes will continue to control pests that could damage your plants for months and you can reapply them if the aphids return.
Root Aphid Treatment: Pyrethrum
1. Spray the Soil
Spray a pyrethrum-based insecticide onto the soil around the root-aphid infested plant. Pyrethrum is a natural, organic insecticide that is derived from the chrysanthemum flower. It is toxic to root aphids and many other garden pests, but safe to use around animals and children at the concentrations recommended for garden use.
2. Water After Application
Water the plant lightly to wash the pyrethrum deep into the soil. Let the plant sit for 12 hours before watering again. The pyrethrum will begin to kill root aphids within hours.
3. Reapply to Prevent Reinfestation
Reapply pyrethrum every two to three weeks or after heavy rains during the growing season to prevent root aphid reinfestation.
Things You Will Need
Clean spray bottle
- While pyrethrum is not toxic to animals or people, it can produce skin irritation in sensitive or allergic people or animals. Keep children and animals away from treated plants for 24 hours after application to minimize this risk.