• Three-cornered alfalfa hopper, Latin name Spissistilus festinus, is part of the Membracidae, or tree hopper family.
• Both nymphs and adults have piercing-sucking mouthparts.
• It was first discovered and identified in 1831.
• Although it has a wide host range, it shows a preference for leguminous species and is an occasional pest of soybeans.
• Spissistilus festinus is established in the Southeastern and Mid-southern U.S.
• Adults typically fly within or just above plant canopies.
• Some studies suggest that populations tend to be greater in no-till or reduced tillage systems.

• Both adults and nymphs are wedge-shaped, and triangular when viewed from above.
• The “three corners” can be observed from the two points at each shoulder and one at the apex of the pronotum.
• Adult bodies are typically very small, 6-7 mm long.
• Coloration on mature adults range from green-brown to vibrant green.
• Nymphs have lighter colored dorsal spines to deter predators.
• Females are distinguishable from males because they have an ovipositor that deposits egg directly into plant material, whereas males have a red tint on the edges of their pronotum.

• Eggs are laid within plant tissue either singly or in small clusters.
• Feeding typically starts in other crop and non-crop species before progressing to soybeans.
  • Examples include cotton, clovers, dock, wild geraniums, sunflowers, tomatoes, etc.
• As the season progresses, the pest beings to move towards soybeans.
• Spissistilus festinus can overwinter as eggs in plant tissue or as adults under cover.

• Spissistilus festinus is a phloem feeder, meaning it sucks the sugary sap out of the plant.
• The removal of nutrients and sugars impede growth of the plant.
• Feeding can occur sporadically on tissues or in a ring around the circumference of the stem.
• The series of lateral punctures can cause a girdle, preventing the plant from transporting nutrients.
• Girdles diminish structural integrity of the targeted stems and petioles, making them more susceptible to their environment.
• Weakened plants may snap and lodge; severity depends on population and growth stage.
• Wounds caused by feeding can also predispose the plant to pathogen attack.

Management Considerations

• There is no universal economic threshold that has been developed for this pest.
• Some states recommend treatment after 50 percent or more of seedling plants are girdled during early infestation.
• During reproductive stages, a treatment threshold of one hopper per sweep (100 per 100 sweeps) is sometimes recommended.
• In Tennessee, treatment for hoppers is recommended when 10 percent or more of plants less than 10-12 inches tall are infested.
• Consult your local university recommendations for best management practices.

• Beyer, B. A., Srinivasan, R., Roberts, P. M., & Abney, M. R. 2017. Biology and Management of the Threecornered Alfalfa Hopper (Hemiptera: Membracidae) in Alfalfa, Soybean, and Peanut. Journal of Integrated Pest Management, 8(1).
• Stewart, S., Thompson McClure, A., & Russ, P. (n.d.). Threecornered Alfalfa Hopper. Retrieved from UT Extension.