Insects on Sweet Basil Plants

Basil-loving Pests

• Sweet basil plants are primarily plagued by five pests: aphids, slugs, Japanese beetles, nematodes and whiteflies.

Symptoms of Infestation

• Signs of whitefly and nematode infestation include yellowed, wilting and/or dropping leaves, while slugs and Japanese beetles will leave holes in the plant's foliage. Aphids excrete a sticky substance called honeydew which is easy to feel on the plant and which can cause the plant to develop black areas.

Treatments

• Control aphids by knocking them off the plant with a strong blast from the hose or by treating the plant with insecticidal soap or neem oil. You can also use insecticidal soap or neem oil to control whiteflies. Bacillus thuringiensis, or Bt, kills nematodes. You must pick Japanese beetles off the plant by hand and drown them in a pail of soapy water, but you can kill slugs with commercial or homemade slug bait traps.