What Insects Eat Sweet Peas?

Aphids

• According to "Rodale's Ultimate Encyclopedia of Organic Gardening,” aphids are the primary pests of sweet pea vines. Squirting plants with liquid soap and water from spray bottles may get rid of the pests. A strong jet of water from the hose will also work because the blasts of water knock off ants that aphids eat. Aluminum foil around the base of sweet pea vines also repels aphids, according to the University of California’s Integrated Pest Management Program.

Nematode

• Nematodes feed on plant roots. They stunt vine growth and kill plants, especially seedlings. Before planting your sweet pea vines, cover the soil with clear plastic for about a month in order to kill nematodes and their eggs. Adding hummus to the soil in the form of compost and peat moss can also help. While marigolds protect many plants from nematodes, annual ornamental vines don’t benefit from their insect-repellant properties, according to the University of California’s IPM Program.

Leaf Miners

• Spindly white lines and spots on sweet pea leaves indicate the presence of leaf miners. While leaf miners don't damage sweet peas as much as aphids, they cause stunted vine growth. Combat them with their natural enemies, such as parasitic wasps, that are available from garden suppliers.

Thrips

• Thrips are gnat-like insects that damage leaves. They also prevent sweet pea flowers from opening. Thwart thrips with many of the same controls used for aphids by removing the pests with blasts of water. Pruning damaged sections will disorient them. Aluminum foil or reflective mulch will also confuse them. Natural predators, including parasitic wasps and green lacewings, are available from garden suppliers.

Spider Mites

• Little red dots on the underside of your sweet pea’s leaves are spider mites. Small infestations cause unsightly foliage, but large colonies kill vines. Properly watered soil can keep populations of the drought-loving pests down. Also, hosing down dusty paths and bare patches of lawn will keep numbers down. Predatory mites that kill spider mites combat them.

Caterpillars

• Caterpillars munch whole sweet pea seedlings. They gnaw holes in foliage and flowers. Examine the plants for the pests, and pick them off the plants. Also, use organic insecticides, such as Bacillus thuringiensis.