Oklahoma State University Stillwater, OK
Oklahoma Alfalfa Oklahoma Cooperative Extension Service Oklahoma Agricultural Experiment Station

STEM GIRDLING BY THREE-CORNERED ALFALFA HOPPER
The three-cornered alfalfa hopper completes several generations per year while feeding ins legume crops such as alfalfa and soybeans. However, populations are rarely high enough in alfalfa in the southern plains to cause noticeable damage until September or October. Nymphs and adults of this species make repeated punctures to feed on plant fluids while moving around stems, which results in girdling of stems. Stems are typically girdled within 2-3" of the soil surface. Leaves on girdled stems become chlorotic and often turn red to purple in color. Stems that have been weakened by girdling often break and lodge.    Although, discoloration of foliage due to damage by the three-cornered alfalfa hopper may be quite noticeable, it is seldom profitable to apply insecticide for control. The only conditions under which control may be warranted would be in instances when damage is observed during vegetative growth of a productive crop of alfalfa. Often, symptoms are observed in fall growth after the last harvest of alfalfa has been taken.    Image of three-cornered alfalfa hopper Image of damage by the three-cornered alfalfa hopper
Richard Berberet, Alfalfa Entomologist  Department of Entomology and Plant Pathology  Oklahoma State University

 

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