Staying Ahead: Managing the corn leafhopper comeback in Texas

Entomologists track in-state progression, offer management insights

Last year, the corn leafhopper made a resurgence as a major pest for corn farmers across parts of the Lone Star State. The pest can transmit pathogens that lead to disease or other issues — preventing Texas farmers from growing a healthy, thriving corn crop.

What’s it “dew”?

• The corn leafhopper produces a sugary substance, called “honeydew,” that can grow on corn stalks and leaves. 
• Honeydew can lead to the growth of sooty mold that may block leaf photosynthesis.
• The pest can transmit four main plant pathogens (two bacterial and two viral), with the potential to cause the primary concern: red stunt disease.
• Symptoms of corn leafhopper infestation: 
  • Yellowing and reddening leaves
  • Rapid death of the lower canopy
  • Death of the ear leaf and corn husks
  • Poor pollination and extensive blank ear tips
  • Incomplete kernel fill
  • Stunted or excessively thin and tall plants
  • Formation of multiple deformed ears from the primary ear position
  • Abnormal tillering

5 Things to know about corn leafhopper

1. It is a semitropical/tropical corn pest thought to have originated in Mexico.
2. It can survive at temperatures of 50 degrees to 68 degrees in the absence of a corn crop, feeding on other grass species. 
3. Corn is the best host for the insect, and it needs corn to reproduce.
4. It can survive on grass species such as eastern gamagrass, sorghum and johnsongrass in the absence of corn.
5. It is one of the most destructive corn pests in Brazil, Paraguay and Argentina. It is an occasional pest in the U.S. that is most common in southern Texas, the southern San Joaquin Valley of California and Florida. 

Preventative measures

• Eliminate volunteer corn: Particularly in regions that do not experience freezing temperatures, as corn can serve as a host for the pest.  
• Plant early: Early-planted corn has been shown to escape corn leafhopper infestations and subsequent issues with pathogens.

Pest progression & monitoring

Corn leafhoppers need to be detected before their population increases, making visual scouting ineffective. David Kerns, Ph.D., the Texas A&M AgriLife Extension Service statewide integrated pest management coordinator, is working with extension agents across the state to monitor the pest’s presence in Texas’ corn fields.

Kerns provides regular online audio updates, which are typically brief and offer a comprehensive overview of corn leafhopper activity across the state. Texas Corn Producers has compiled these updates into an easily accessible playlist on SoundCloud: Texas Corn Producers Corn Leafhopper Audio Updates.

Effective management

• The most critical window to prevent yield-damaging infections is the VE to V5 growth stage; however, protecting through V8 is recommended. 
• Corn should be scouted from V3 through V8 to lessen the risk of red stunt transmission.
• Farmers can apply insecticides during emergence through V8 when corn leafhoppers are detected, especially for late-planted corn or second-crop corn.

Access additional information about the corn leafhopper from Texas A&M AgriLife HERE.