Potato Leafhopper (Empoasca fabae)
Integrated Pest Management for Commercial Horticulture
extension.umd.edu/ipm
PEST ALERT - 2014 (revised)
Introduction
Every year starting in May in Maryland, American red maples suffer
from potato leafhopper damage. The curled and twisted tip growth is all
too familiar to most nursery managers. In dry years the damage is usually
heavier.
Generally, the potato leafhopper (Empoasca fabae) cannot overwinter
in the North because of sensitivity of the eggs to the cold. On occasion,
the leafhopper has been found overwintering in the southern area of the
Eastern Shore of Maryland. The potato leafhopper is found year-round in
the Gulf of Mexico. In May and June the prevailing northern winds carry
the leafhoppers into the Jet stream and drop them out in states such as
Maryland.
Life Cycle
The females will deposit eggs in slits in veins on the undersides of maple
Close-up of potato leafhopper
leaves or in petioles. It is very difficult to detect the eggs. The nymphs
damage on red maple
hatch in about 7 – 14 days after egg laying. The nymphs go through 5
instars (shed their skin 5 times). Up to 6 generations per summer have
been recorded in Maryland. Potato leafhopper nymphs and adults have
piercing-sucking mouthparts and feed in the vascular tissue, primarily
in the phloem. As the stylet probes the plant tissue, internal cells are
lacerated and plants cells fragmented. Salivary toxins injected into tissues
cause the cells to collapse. When vascular tissue is damaged in shoots,
the tip growth tissue becomes distorted. This feeding by the leafhopper
causes tip growth on the maples to curl over and harden. This damage
is typically referred to as ‘hopperburn’. The multiple generations keep
damaging the new tip growth that flushes out on the maples.
Potato leafhopper nymph (right) and adult (left)
Overview view of potato
leafhopper damage on tree
Solutions
Plant breeders at the National Arboretum have released 3 red maples (Acer rubrum) that have fair resistance
to leafhopper damage. A. rubrum ‘Somerset’ (a cross between A. rubrum ‘October Glory’ and A. rubrum
‘Autumn Flame’) and ‘Sun Valley’ (a cross between A. rubrum ‘Red Sunset’ and A. rubrum ‘Autumn Flame’)
were released to the nursery trade in 1994. ‘Sun Valley’ is hardy in zone 4 – 7. ‘Somerset’ is hardy to Zone
8. Both of these male selections have excellent fall color that is long lasting and have significant tolerance
to leafhopper injury. ‘Somerset’ at 12 years old is 23 feet tall with an 11 foot crown. ‘Sun Valley’ at 10 years
of age is 21 feet tall and 10 feet wide. A. rubrum ‘Brandywine’ (another cross between A. rubrum ‘October
Glory’ and A. rubrum ‘Autumn Flame’) is a male selection that was also released in 1994 and has similar
resistance to leafhopper damage. The fall color on this red maple is a brilliant red-purple. Over 12 years, it can
grow to 25 feet tall with a 12 foot crown.
Chemical Control Options
Read labels on the pesticide container to see if they impact pollinators. Do not spray plants that are in bloom
with materials that have listed on the label “do not spray when a plant is in bloom”. The impact of the
neonicotinoid class of insecticides on pollinating insects such as honey bees and native bees may be a cause
of concern. Presently, it is unknown at what level, if any, neonicotinoids are present in the blooms or pollen.
Applying imidaclopid (Merit, Mallet, and many other brand names) as a foliar spray after bloom time reduces
the chance that pollinators will contact the insecticide. Foliar applications of the material does not result in long
term persistence in the plant. When imidacloprid is applied as a soil drench, it acts differently and remains in a
plant for longer periods of time. If applied as a soil drench, imidacloprid has to be applied 2 to 3 months before
the targeted insect is present. The chemical could be present in flower blooms, thus impacting pollinators. Soil
applications of imidacloprid that are absorbed through roots result in the plant metabolizing the compounds.
Some of the resulting breakdown products are equally toxic or even more toxic to pollinators than the original
compound. Also, the imidacloprid when absorbed through roots of plants remains in the plant for 2 to 3 years,
and it is unknown if it is present in the pollen for this length of time.
Dinotefuran (Safari, Transtect) is also a neonicotinoid. It is more water soluble and is taken up by plants
faster than imidacloprid. It can be applied as a basal trunk spray and be taken up into foliage in a couple of
weeks. When dinotefuran is uptaken into the plant, it also forms metabolites, but they can break down rapidly
compared to imidacloprid, and are non-detectable by the end of the season.
Acetamiprid is another neonicotinoid that is highly water soluble, and has a realatively short residual lasting a
couple of weeks. Apply acetamiprid after bloom only as a foliar application. You can make foliar applications
of Acephate (Orthene), but this treatment would have to be repeated for the multiple generations that occur
over the summer. Acetamiprid (Tristar), Discus and Kontos can also be applied as a foliar spray in nursery
beds.
Potato Leafhopper (Empoasca fabae)
by
Stanton Gill, Extension Specialist, IPM and Entomology
Central Maryland Research and Education Center, University of Maryland Extension
The information given herein is supplied with the understanding that no discrimination is intended
and no endorsement by University of Maryland Extension is implied.
Read labels carefully before applying any pesticides.
Photographs are by Suzanne Klick and Stanton Gill unless stated otherwise.
The University of Maryland Extension programs are open to any person and will not discriminate against anyone because of race, age, sex, color, sexual orientation,
physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, and gender identity or expression.
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