If you are seeing white foam on your perennials, chances are spittlebugs have moved onto the plants. Extension specialists at Univ. of Ma. and Univ. of Conn. said the bugs don’t generally harm the plants and create more cosmetic damage. Plants most often affected include Achillea, Boltonia, Coreopsis, Phlox and Potentilla.
These sucking insects are about 1/8-inch long. The white foam appears along the stems and leaf axils and surrounds the light green nymphs. The foam helps the nymphs stay moist and protects them from predators. Univ. of Conn. extension horticulture and greenhouse IPM specialist Leanne Pundt said the spittle masses can be removed by hand or a forceful water spray can be used to dislodge the nymphs.
Pictured: Spittlebug nymph on Achillea.
Photo by Tina Smith, Univ. of Ma.
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