Wisterias are fast growing vines that are often grown as trees or shrubs. They produce clusters of drooping flowers that are white, pink or blue. Wisterias are easy to grow because they're very adaptable. However, they are prone to attack by a large number of insects, like leafhoppers, skippers, lantern bugs and scales.
Consult your gardening guide to find out what insect pests wisterias are susceptible to. County extensions provide gardening guides and fact sheets online. Other sources include gardening organisations like the National Gardening Association.
Compare the insects that are eating your wisteria with pictures of insects in your insect identification field guide. Since control varies, depending on the species of insects, you need to know exactly what's attacking your plant. Jot down the names of any insects you identify.
Visit your local gardening centre and speak to an expert about different options they offer for controlling the pests on your list. For instance, you may need to purchase aluminium foil mulches, insecticidal soaps, neem oil or systemic insecticides, depending on whether you have aphids, soft scales or leafhoppers.
Read labels before purchasing chemicals. Some insecticides will destroy beneficial insects, like lady beetles, along with your insect pests. Some insecticides are poisonous to pets and children, or may damage other plants growing nearby. Know what you're buying.
Handpick any caterpillar pests and put them in a pail of soapy water to dispose of them first. Spray a strong stream of water on your plants to knock aphids off the leaves, if they are feeding on your wisteria. Employ all nonchemical treatments first to reduce how much contact you have with chemicals.
Apply insecticides according to label instructions. Some insecticides can't be applied if the temperature is over 32.2 degrees C. Others must be applied when the insect pest is small. Follow directions carefully to ensure proper treatment and to prevent injury to yourself or your plants.
Use the least poisonous treatments first. For instance, if you need an insecticide, consider using horticultural oils, neem oil or Bacillus thuringiensis, instead of stronger chemicals like malathion or permethrin, because they don't leave toxic residues behind that kill beneficial insects like more powerful chemicals do. Apply insecticides to both sides of the leaves to ensure that you reach all pests. Eliminate weeds from your garden, because they often serve as alternate hosts for insect pests.
Wear protective clothing, including water-impervious gloves, long-sleeved shirt and eye protection, when you're applying insecticides. Wash clothes separately when you're done.