Aphids and Hydroponic Bug Killers

Aphids

• Aphids are sometimes referred to as plant lice and are small insects that range in color, from black, brown and white, to pink, green, red, orange or yellow. Aphids reproduce quickly and asexually, oftentimes giving birth to three to 100 daughter aphids each day. The daughter aphids start reproducing shortly after birth. This leads to rapid infestations. Aphids feed on the sap from the plant then exude honeydew, a sticky-sweet substance that breeds sooty mold and attracts other insects, such as ants, that feed on the honeydew.

Aphid Damage

• As aphids feed on hydroponic plants, the leaves start to curl, turn mottled and yellow, and eventually die. Large infestations may kill the entire plant if the problem is left unchecked. As the aphids excrete honeydew, sooty mold begins to breed on the sticky substance. Sooty mold is a grayish-black, powdery pathogen that prevents the plant from photosynthesizing, eventually killing it.

Prevention

• Aphids enter the indoor grow room from the outside. Keep track of the outdoor aphid population by setting sticky traps near windows and doors. Keep the grow area clean and keep the indoor garden enclosed to keep outside pests from entering. It's best to have a separate set of indoor and outdoor gardening tools so that small pests or eggs aren't transported from outside to indoors; however, if the same tools are used, disinfect them thoroughly first.

Insecticidal Soap

• The same insecticides that are used to kill aphids outside are used for hydroponic gardens as well. Dip a cloth in insecticidal soap and wipe the aphids off of the plant, including the undersides of the leaves. Commercial insecticidal soaps are available, or you can make one at home by filling a clean spray bottle with water and a squirt of mild dish soap. Spray the infested areas every four to five days until the problem ceases.

Ryania

• The stems and roots of the tropical shrub, Ryania speciosa, are powdered into a dust that acts as a stomach poison to aphids and many other insects. As the aphids feed on the plant, they ingest the poisonous plant powder, stop feeding and die within 24 hours. Follow the directions for how to dust Ryania onto the foliage. The poison persists for approximately two weeks.

Pyrethrin and Pyrethroids

• Pyrethin is a chemical produced by chrysanthemums that kills many insects, including aphids, on contact. Pyrethroids are a synthetic, stronger, more effective chemical based on pyrethrin's structure. They come in many forms, including, aerosol, liquid and powder. Both are somewhat toxic to animals so wear protective gear and clothing when applying and follow the directions on the product carefully.

Neem Oil

• Neem oil contains extract from the neem seed, which is an effective pesticide and fungicide. When purchasing neem oil, look for cold-pressed oil that is stronger and purer. Mix neem oil with water that has a pH below 7 and shake it up constantly while spraying. Spray the foliage and under the leaves. Neem causes the plant to become unpalatable to aphids; and because neem has a systemic effect that soaks inside of the plant, even those aphids that continue to feed are unable to reproduce.