Stem Breaks from Alfalfa Hopper

The three-cornered alfalfa hopper is a green, wedge-shaped, sap-feeding insect (Figure 1) that causes distinct physical injury. Adults and nymphs girdle stems, lateral branches, or petioles as they feed on legumes and a variety of other plants. Symptoms include yellowing and wilting above the callus tissue that develops at the injury site.  Damaged plants may also break or lodge.

Figure 1. Three-cornered alfalfa hopper adult (University of California IPM)

Figure 1. Three-cornered alfalfa hopper adult (University of California IPM)

Low numbers of three-cornered alfalfa hoppers are probably present in many Kentucky fields in late summer, but they can reach damaging levels during late summer in alfalfa and double-cropped or late-planted soybeans.

Management

Generally, an insecticide application is not needed at this point in the season.

 

 

By Lee Townsend, Extension Entomologist

 

 

Posted in Forages, Grains