The root aphids (Phemphigus) is a plant pest that makes its home on the roots of plants. They feed by sucking the juices out of the roots. This causes plants to lose the nutrition they need to thrive. You may notice your plants start to wilt or wither without any apparent explanation. Although root aphids appear either light green or off-white in colour, you most likely won't spot them. To tell whether root aphids are present, however, lift the plant and examine the roots. A white powdery wax indicates root aphids.
Mix one packet of nematodes with 1 gallon of water. Fill a spray bottle with this mixture and saturate your plant soil with it. The nematodes will find the root aphids for you and kill them from the inside out. Nematodes are safe for use around plants, pets and people.
Administer an insecticide with the active ingredient beauveria bassiana. Beauveria bassiana is a fungus that infects and kills root aphids. It will not cause any harm to the plant. Be sure to follow all the instructions on the product label for effectiveness and safety.
Spray the plant soil with an organic pyrethrum. This all-natural insecticide is made from dried chrysanthemums. It is a good choice for killing root aphids if the affected plant is a houseplant. This is because it is safe to use around children and pets. Be sure to follow the product label to completely eradicate the root aphids.
Mix an insecticide with the active ingredient azadirachtin with water based on the product's instruction label. Azadirachtin is organic and works to kill root aphids by preventing them from eating or moulting. Eventually, they become paralysed and die.
Repeat your choice of treatment per the instruction label until all the root aphids have been killed.
Do not use neem oil to kill the root aphids. Neem oil is often used to kill aphids, but it can cause damage to plant roots. Since your plant roots are already damaged by the aphids, they might not survive the additional damage done by the neem oil.