Meet the Aster Leafhopper and Learn How to Distinguish it From the Corn Leafhopper

Last year’s corn stunt disease outbreak, caused by the corn leafhopper transmitting pathogens associated with corn stunt disease, has been on everyone’s minds. Over the past few weeks, I’ve received several calls from growers, crop consultants, and industry partners concerned about leafhoppers in corn. Fortunately, none have been corn leafhoppers, the vast majority have instead been aster leafhoppers. So far, no corn leafhoppers have been reported north of central Texas. Oklahoma did not have any reports of overwintering corn leafhoppers so if we have the insect this year it will need to migrate northward from where it currently resides. For a refresher on the corn leafhopper and corn stunt disease, check out these two previously posted OSU Pest e-Alerts: EPP-25-3 and EPP-23-17.

 

Leafhoppers in general are insects that we have had for many years in our row and field crops. But we likely did not pay attention to them or notice them until this past year due to our heightened awareness of their existence thanks to the corn leafhopper and corn stunt disease. Below is guidance on how to distinguish between the corn leafhopper and aster leafhopper. Remember, if the corn leafhopper is detected in the state, OSU Extension will notify growers, consultants, and industry partners through Pest e-Alerts and our social media channels.

 

Aster Leafhopper Overview

The aster leafhopper (aka six spotted leafhopper), Macrosteles quadrilineatus, is native to North America and can be found in every U.S. state, as well as Canada. This polyphagous insect feeds on over 300 host plant species including weeds, vegetables, and cereals. Like many other leafhoppers, the aster leafhopper can be a vector of pathogens that cause disease, but corn stunt is not one of them. Instead, aster leafhoppers cause problems in traditional vegetable growing operations, as well as floral production. There is currently no concern for this insect being a vector of disease in row or field crops, including corn. Check out the OSU Pest a-Alert EPP-23-1 to learn more about this insect and aster yellows disease.

 

Aster Leafhopper Versus Corn Leafhopper

The corn leafhopper (Photo 1A) and the aster leafhopper, as well as many other leafhopper species have two black dots located between the eyes of the insect (Photo 1). Aster leafhopper adults are 0.125 inches (3 mm) long, with transparent wings that bear strong veins, and darkly colored abdomens (Photo 1B). Their dark abdomen can cause the aster leafhopper to appear grey when you see them in the field. Their long wings can also make the insect appear to have a similar appearance to the corn leafhopper (Dalbulus maidis) (Photo 1).

 

Photo 1A. Above (dorsal) view of the corn leafhopper (A). The corn leafhopper has two black dots between their eyes. These dots are surrounded by light/white “halos”. The corn leafhopper also has light in color wing veins.

 

Photo 1B. The aster leafhopper also has two black dots between their eyes, however, there is no light coloration surrounding these dots. The aster leafhopper also has dark wing veins, making the veins appear thicker than those of the corn leafhopper.

 

Characteristics that differentiate the corn leafhopper from the aster leafhopper are as follows. When viewed from above (dorsally): 1) the corn leafhopper’s dots between the eyes have a white halo around them and the aster leafhopper’s dots between eyes lack the white halo and 2) the corn leafhopper has lighter/finer wing venation than the aster leafhopper (Photo 1). When when viewed from their underside (ventrally) 3) the corn leafhopper lacks markings on their face whereas the aster leafhopper has lines/spot on the face and 4) the abdomen of the corn leafhopper lacks the dark coloration of the aster leafhopper (Photo 2).

 

Photo 2 A & B. Underside (ventral) view of the corn leafhopper (A) and the aster leafhopper (B). A) The corn leafhopper has no markings on the face and their abdomen is lighter in color. B) The aster leafhopper has markings on the face as well as a dark abdomen color.

 

Confirming Corn Leafhopper Identification

It is important to note that many insects will have their cuticle darken as they age. This, along with there being light and dark morphs of many insects can lend to additional confusion when distinguishing one species from another. If you believe that you have a corn leafhopper then you need to collect the insect and send it to a trained entomologist that can verify the identity of the insect under the microscope. Leafhoppers in general are fast moving insects but they can be collected in an insect net or using a handheld vacuum (see EPP-25-3). You can submit samples to the OSU Plant Disease and Insect Diagnostic Lab for identification by OSU Cropping Systems Extension Entomologist Dr. Ashleigh Faris.