Potato vine (Solanum jasminoides) is a flowering vine that does not create vegetables of any kind. This evergreen plant develops in U.S. Department of Agriculture plant hardiness zones 9 through 11, producing fragrant bluish-white flowers. Potato vines attract various guests with their leaf and blooms, including hummingbirds and butterflies. Some butterflies utilize the potato vine as a host plant for their larvae — caterpillars — which utilize the plant for shelter and food.
Despite their name, tomato hornworms don’t restrict their feeding to plants. These annoying pests feed any plant from the nightshade family (Solanum), for example, flowering potato vine. Tomato hornworms are big caterpillars measuring around 4 inches long, with a bright green body and white stripes on their sides. The most distinguishing quality of this caterpillar is the horn located at its rear. These pests feed on foliage, leaving the leaves with holes, notches and ragged edges. In addition they can consume little stems and entire leaves. Hawk moths — also called sphinx or hummingbird moths — would be the adult stage of the tomato hornworm.
Instead of harsh pesticides that may kill beneficial insects along with the caterpillars, utilize a bacterium insecticide, such as Bacillus thuringiensis. Bacillus thuringiensis kurstaki strain is naturally found in the dirt and targets only the larval stage of moths and butterflies. You spray it on the potato vine plant, and after the caterpillar absorbs the bacteria, it stops feeding and dies of starvation. This stomach poison usually kills the caterpillar within three days. Bacillus thuringiensis is safe to use around people, mammals, birds, pets and fish.
Manually picking caterpillars off the potato vine is generally sufficient to control modest infestations. As soon as you’ve picked the caterpillar off, put it into a bucket of hot, soapy water. Think about wearing a pair of work gloves while eliminating the caterpillars to prevent any potential skin irritation they may cause. Hornworms may appear menacing but are not harmful to pets or humans.
Several predatory insects will dominate caterpillars on your garden naturally. Trichogramma and Hyposoter exiguae are two little parasitic wasps that attack hornworms. Trichogramma prey around the hornworm eggs while Hyposoter exiguae lays its eggs in the hornworm caterpillar. You can attract these beneficial predators by expanding plants from the mint family near the potato vine. This includes sage (Salvia spp.) , catnip (Nepeta cataria) and peppermint (Mentha x piperita).