| POTATO
LEAFHOPPER
 There
are many insects under the umbrella term of “leafhoppers” of which
the two that are economically important to potato growers are the
aster leafhopper (Macrosteles quadrillineatus) and the potato leafhopper
(Empoasca fabae). These are pests throughout the US mid-west and
southern Canada. Among entomologists, the leafhopper ranks third
as the most important insect pest in North America, after the Colorado
potato beetle and green peach aphid. Of the two leafhoppers above,
the potato leafhopper has the most effect on yield reduction.
POTATO
LEAFHOPPER
 Potato
leafhopper (Empoasca fabae) damages crops through direct feeding
on the sap. It is a piercing-sucking insect that causes injury referred
to as “hopperburn.” This is characterized by necrosis of leaflets
starting at the tips and margins resulting, with progress, in defoliation.
Description
Adult
potato leafhoppers are wedge or spindle-shaped, and about an eighth
of an inch long. They appear bright lime-green to yellow green with
white markings. Wings are transparent green and are folded back
when at rest. They have a variable number of white spots on top
of their head and along their thorax. Nymphs are similar to adults
but are smaller and wingless. Several nymphal stages occur in the
generation.
Life
Cycle
Potato
leafhoppers overwinter as adults between southern Louisiana and
northern Florida. They fly north in the spring on the winds in the
upper atmospheric levels. They are mostly found in Wisconsin and
Illinois during the growing season. However, in some years, they
have been identified as far west as the Panhandle of Nebraska and
as far east as Maine.
Adults
live 30-40 days but may live as much as 90 days. Two to three small
white eggs are laid per day onto stems or large leaf veins, and
200 eggs per adult life is possible. Potato leafhoppers will lay
eggs on potatoes. Eggs hatch in ten days forming the first of several
nymphal stages. Nymphal stages are short and within 12 days of hatching
the nymphs will become adults. Adults are able to lay eggs six days
later. Nymphs move backwards and sideways in a crab-like fashion
and cannot move from field to field. There can be one to three overlapping
generations per season in the north-central States.
Damage
Potato
leafhopper, primarily adults, cause feeding injury to potato plants.
They feed on the underside of leaflets. Injury starts with a yellowing
along leaflet margins with a slight rolling. This slight injury
is soon followed by a gradual browning starting at the leaflet’s
tip and margin (hopperburn), and extending basipetally until the
leaflet is all dead and desiccated. The browning is due to cellular
death or necrosis. Defoliation will occur. The result is a reduction
in yield. No effects on tuber quality has been reported by potato
leafhopper.
Management
Sustainable
Agriculture — Monitoring fields for populations and correctly identifying
the leafhopper is essential to good management. There are many leafhoppers
that do not damage potato. A threshold for treatment has been established
for potato leafhopper as one nymph per 10 leaves. Sample 35 leaves,
three to five times in the field.
Chemical
Management — Many insecticides will kill leafhoppers. At planting,
Admire, Platinum, Thimet and DiSyston are common. Foliar treatments
include Actara, Asana, Ambush/Pounce, Baythroid, Dimethoate (formerly
Cygon, also used for false chinch bug), Furadan (also used for sand(hill)
chafer), Monitor (also used against aphids), Provado, and Thiodan.
For gardening, Sevin is recommended.
Effect
of Seed and In-furrow Treatments on Leafhopper Symptoms on Potato
Plants in 2001 at Scottsbluff, NE.
| Seed
Treatment |
In-Furrow
Treatment |
Hopperburn
% Plants |
Yield
of US #1
cwt/acre |
| Maxim
MZ 10.1D1 |
none |
16
A2 |
322
B |
| Maxim
MZ 10.1D |
Platinum
2SC |
2.7B |
368A |
| Maxim
MZ Adage |
none |
3.5
B |
389
A |
| Tops
MZ 2.5D |
none |
11
A |
325
B |
| Tops
MZ 2.5D |
Admire
2F |
2.1
B |
390
A |
| Tops
MZ Gaucho |
none |
5.9
B |
377
A |
|
1
Maxim MZ treatments applied at 8 oz/cwt, Tops MZ at 12 oz/cwt,
Admire at 1.3 fluid oz/1000 linear feet, and Platinum at 0.55 fluid
oz/1000 linear feet.
2 Treatments in columns followed by different letters
were significantly different from each other at p=0.05.
Hosts
for potato leafhopper besides potato include edible beans especially
lima and snap, alfalfa, and soybeans which is not seriously affected.
When alfalfa is harvested, adults may move into potato fields; nymphs
die of starvation.
Quick
Review / Potato Leafhopper
Appearance:
- Adults
- bright green, variable white spots, 1/8 inch long
- Nymph
- like adult but smaller and wingless
Life
Cycle:
- Overwinters
- Louisiana to Florida
- One
to three generation/ season in north-central U.S.
- Adults
- June to early July
Damage:
- Adult
- feeding on sap (sucking-piercing insect)
- Nymph
- same
Management:
- Monitor
and Identify
- Economic
Threshold = 1 nymph/10 leaves
- At-planting
Insecticides
- Foliar
Insecticide
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