How to Manage Pests
UC Pest Management Guidelines
Sugarbeet
Empoasca Leafhoppers
Scientific names: Empoasca fabae and Empoasca solana
(Reviewed 11/05,
updated 11/05)
In this Guideline:
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The two species Empoasca fabaeand E. solana constitute over 90%
of the Empoasca species found in
sugarbeet. They are nearly identical morphologically and can only be
distinguished by experts. The damage they cause is also nearly identical as are
the treatment guidelines.
Empoasca
leafhoppers are small (0.125 inch long), bright green, wedge-shaped insects. They may be
distinguished from the green form of beet leafhopper by the lack of dark markings on the body. The small, wingless nymphs (immatures) are
also wedge shaped and green and move rapidly forward, backward, and from side
to side. Both adults and immatures are found primarily on the underside of
leaves.
Empoasca leafhoppers cause a symptom known as hopperburn in
which the leaf margins turn yellow, particularly at the leaf tip, and these
areas soon become necrotic. The entire leaf may become yellowed and the
symptoms often resemble virus symptoms. The presence of adult and immature
leafhoppers on the undersurface of the leaf serve to distinguish leafhopper
injury from virus symptoms or mineral deficiencies. Empoasca leafhoppers do not
spread beet curly top virus.
Sample for Empoasca leafhoppers by counting the number of adults and
nymphs per leaf. Examine a minimum of 10 leaves from 10 plants in at least four
areas of the field. Pick fully expanded leaves, avoiding older leaves or leaves
in contact with the ground. Also, select leaves that are shaded by other leaves
because leafhoppers try to avoid the sun. Leafhoppers are found on the under
surface of the leaf, so turn the leaf over and QUICKLY count the number of
leafhoppers; both adults and immatures can run very fast so you must be quick.
Before starting your actual count, look at and count three to four leaves so
that you will know what the leafhoppers look like, particularly the small ones,
and how they behave. Then begin your sampling and actual counts.
Apply treatments when leafhoppers
(both nymphs and adults) reach 10 to 15 per leaf. Use the lower number for
fields 2 to 3 months up to several months from harvest. Use the higher number
for fields within 1 to 2 months of harvest. Do not treat if fields are within 2
to 3 weeks of harvest.
| Common name |
Amount/Acre |
P.H.I.+ |
| (trade name) |
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(days) |
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| When choosing a pesticide, consider information relating
to water quality and impact on natural enemies and bees.
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| A. |
PHORATE* |
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(Thimet) 20G |
4.5 oz/1000 ft. row |
30 |
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MODE OF ACTION: An organophosphate (Group 1B)1
insecticide.
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COMMENTS: Do not feed tops to livestock. Do not place Thimet granules in contact with seed. |
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| B. |
OXYDEMETON-METHYL* |
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(Metasystox-R) SC |
1.5-3 pt |
30-tops and roots |
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MODE OF ACTION: An organophosphate (Group 1B)1
insecticide.
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COMMENTS: No more than 2 applications/year. |
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| C. |
NALED* |
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(Dibrom 8) |
1 pt |
2 |
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MODE OF ACTION: An organophosphate (Group 1B)1
insecticide.
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| D. |
ESFENVALERATE* |
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(Asana XL) |
5.8-9.6 fl oz |
21 |
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MODE OF ACTION: A pyrethroid (Group 3)1
insecticide.
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UC IPM Pest Management Guidelines: Sugarbeet
UC ANR Publication 3469
Insects and Mites
C. G. Summers, Entomology, Kearney Agricultural Center, Parlier
D. R. Haviland, UC IPM Program, Kern Co.
L. D. Godfrey, Entomology, UC Davis
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