Leafhoppers belong to Hemiptera: Cicadellidae and one of the most well-studied species is the potato leafhopper, Empoasca fabae Harris. It has been proven ^(1,2) that these insects are long-range migrants, and tend to colonize an area based on surface airflow convection currents and high and low pressure fronts. Because they can be significant agricultural pests (alfalfa, clover, beans, tomato, potato, hops, maple, apple), it is important to understand the factors that contribute to their abundance…

Potato leafhopper overwinters only in Texas and the south-eastern United States⁽⁴⁾. A 1964 study used sweep nets and light traps to track the arrival of potato leafhopper in Wisconsin then compared it to wind and temperature patterns, and found significant correlations (FIG. 1)⁽¹⁾. When there was sufficient wind speed (>20 mph) and warm temperatures within the air column (>13.9C), leafhoppers could be transported northward on what is now called the “Mississippi Flyway”⁴ over 800 miles!

Baker et al. (2015) have continued assessing this pattern, and found that E. fabae is arriving into eastern U.S. states about 10 days earlier than it used to. However, advances in transgenic resistance (alfalfa) and systemic insecticides (potato) have mitigated the impact thus far.

Adult potato leafhoppers are about half the size of a grain of rice (3mm), bright green, and wedge shaped. They can be distinguished by the six white dots just behind their head (FIG. 2). Leafhoppers feed by piercing and sucking, and the toxins in their saliva cause drying and curling of leaf tissue. This particular type of damage is called “hopperburn“ and can be hard to diagnose because leafhoppers are so small and mobile, they’re rarely detected. To monitor, look on the underside of leaves, use a vacuum sampler, or yellow sticky cards deployed along field edges.

NOTE: E. fabae has been detected in California⁽⁶⁾, but if you’ve read this far, please take a moment to learn about other, more common leafhoppers in Oregon including beet leafhopper and aster leafhopper that are important vectors of plant pathogens.

1. _{Baker, M. B., et al. (2015). “Climate Change and Phenology: Empoasca fabae (Hemiptera: Cicadellidae) Migration and Severity of Impact.” PLoS One 10(5): e0124915.}
2. _{Pienkowski, R. L. and J. T. Medler (1964). “Synoptic Weather Conditions Associated with Long-Range Movement of the Potato Leafhopper, Empoasca fabae, into Wisconsin.” Annals of the Entomological Society of America 57(5): 588-591.}
3. _{Dietrich Leafhopper Lab FAQ page “What is a leafhopper?”, Illinois Natural History Survey Prairie Research Institute}
4. _{Taylor, R.A.J. and E.J Shields (2018). Revisiting Potato Leafhopper, Empoasca fabae (Harris), Migration: Implications in a World Where Invasive Insects are All Too Common, American Entomologist, Volume 64, Issue 1, Spring 2018, Pages 44–51, https://doi.org/10.1093/ae/tmy009}
5. _{Zahniser, J. Smithsonian Institute Interactive key to the Deltocephalinae}
6. _{GBIF.org occurrence records for E. fabae}