How to Manage Pests
UC Pest Management Guidelines
Scientific Name: Macrosteles fascifrons
In this Guideline:
Several species of leafhoppers feed on rice plants in California,
but the only one known to be of economic importance is the aster leafhopper.
The adults are about 0.125 inch long, with transparent wings that are strongly
veined, and body background colors of gray and black. The nymphs have small wing pads in their last instar and range in color from yellow to
Leafhoppers usually pass the winter in the egg stage, although
nymphs and adults may be found all year round. The leafhopper inserts its eggs
into tender plant tissues. Wingless nymphs hatch from the eggs and go through
four to five molts before reaching maturity. Up to six generations may be
completed between spring and fall.
Although leafhoppers can be present in fields during most of the
growing season, the heaviest populations usually occur from early July through
mid-August. Leafhoppers feed on rice plants by sucking up plant fluids through
their long, piercing mouthparts. Although they are not known to vector of any
rice pathogens in California, leafhoppers may occasionally occur in sufficient
numbers to cause damage by their feeding. Injury associated with leafhoppers include stippling,
yellowing, and drying leaves. Leafhoppers prefer senescing leaves, and symptoms
usually occur on older leaves first. Leafhoppers are very mobile; adults fly and
nymphs jump. Thus, infestations are rarely localized but appear generally
throughout the field.
High populations of this pest are associated with weedy rice fields.
Control weeds and monitor during the summer to determine the need to treat.
Predation can provide significant reduction of leafhopper populations.
Small plot studies in rice paddies have shown a spider, Pardosa
ramulosa, to significantly reduce
populations of the aster leafhopper.
High populations of aster leafhoppers are frequently associated with
paddies heavily infested with broadleaf weeds and sedges. An early and
effective weed control program is an important way to discourage the
development of economically damaging populations of leafhoppers on weeds and
future movement of leafhoppers to rice.
Organically Acceptable Methods
Cultural controls, such as described above, and reliance on biological
control are organically acceptable methods.
Monitoring and Treatment Decisions
Observe fields weekly from July through August for leafhoppers and their damage. Leaf
yellowing and stippling can be associated with other stresses, so always check
for the presence of leafhoppers. Leafhopper adults, nymphs, and molted skins
are easy to see as you walk slowly through a field. Always inspect fields
carefully after broadleaf herbicide treatment; the killing of broadleaf weeds
may cause the leafhoppers to move from the dying weeds to the rice plants.
Although there are no available treatment thresholds, a good rule of thumb is
to treat when young upper leaves become infested and begin to dry.
|When choosing a
pesticide, consider information relating to the impact
on natural enemies and honey bees and environmental impact Not all registered pesticides are listed. Always read label of product being used.
||(Sevin) XLR Plus
||MODE OF ACTION GROUP NUMBER1: 1A
||COMMENTS: Do not apply
within 15 days before or after application of propanil or crop injury may result.
UC IPM Pest Management Guidelines: Rice
UC ANR Publication 3465
L. D. Godfrey, Entomology,
L. A. Espino, UC Cooperative Extension, Colusa County
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