Meadow Spittlebug in Alfalfa

Crop Injury: Meadow spittlebug (Philaenus spumarius) is a minor pest of alfalfa and other legume forage crops. Injury to alfalfa occurs when nymphs and adults use piercing-sucking mouthparts to consume sap from plants. First harvest yield can be greatly reduced when high nymph populations are present. Plant symptoms include stunting, wilting, rosetting, and early stem maturation, but yellowing does not occur.

Pest Description: This insect produces small, spit-like masses on plants, which surround and protect developing nymphs. Light green nymphs lack wings and have red eyes. Adult spittlebugs are tan to brown; occasionally they have striped or mottled markings. Each mass of spittle has one to 25 spittlebugs. 

Life Cycle: Meadow spittlebugs overwinter as eggs and hatch in the spring. They secrete plant sap along with a mucus-like substance and fill it with air bubbles. This frothy “spittle” protects the nymphs from drying out and natural enemies. There are five instars before adulthood is reached. Adults feed throughout the remainder of the season and lay eggs in plant debris. Meadow spittlebugs have one generation per year.

Scouting: Risk is highest in second-year alfalfa originally established with a companion small grain crop.

Management: Alfalfa varieties tolerant or resistant to meadow spittlebug are available. Second year alfalfa infestations may be reduced by removing grass companion crop stubble from a field. Insecticides can also be used if the economic threshold of one spittlebug per stem is observed. Be aware that insecticide use can kill important natural enemies of the meadow spittlebug and other alfalfa pest insects.

Prepared and reviewed by the Alfalfa Pest Management Working Group.