How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST

The potato leafhopper is a potential pest of citrus in some areas, especially in groves near tomato fields, cotton fields, or pastures in the San Joaquin Valley. It is a green, slender insect with bristlelike antennae and rows of spines along its hind legs. It breeds in large numbers on wild plants and field crops. During late summer and fall, the leafhoppers may migrate to citrus groves to spend the winter in the shelter of the trees.

DAMAGE

The potato leafhopper feeds on fruit by puncturing rind cells, causing yellowish to light brown, roundish scars on fruit. The scars are particularly apparent on green fruit and resemble thrips oviposition scars except they are more clustered and do not have darkened centers.

MANAGEMENT

Leafhoppers are not a problem every year. In addition, they do not remain in the orchard long. Usually by the time they are detected, the leafhoppers are already gone; a preventive treatment is best if there is a history of problems with this pest. A yellow, sticky card, such as the one used for the California red scale, or traps can be used to help determine if leafhoppers are present.

If you apply a Bordeaux spray in fall against brown rot and Septoria, you may want to add some additional hydrated lime to repel leafhoppers. Because this is a preventive treatment, it must be made before migration into the grove occurs.

Common name		Amount to Use	R.E.I.+	P.H.I.+
(trade name)		(type of coverage)	(hours)	(days)
When choosing a pesticide, consider information relating to impact on natural enemies and honey bees as well as environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A.	HYDRATED LIME#	15–30 lb/100 gal (OC)	0	0
	RANGE OF ACTIVITY: Pests: narrow (leafhoppers); Natural enemies: interferes with searching ability of many natural enemies
	PERSISTENCE: Pests: long; Natural enemies: long
	COMMENTS: For use on all varieties.
**	OC - Outside coverage uses 100–250 gal water/acre.
+	Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
#	Acceptable for use on organically grown produce.

PUBLICATION

UC IPM Pest Management Guidelines: Citrus
UC ANR Publication 3441
Insects, Mites, and Snails
E. E. Grafton-Cardwell, Kearney Agricultural Center, Parlier
J. G. Morse, Entomology, UC Riverside
N. V. O‘Connell, UC Cooperative Extension, Tulare County
P. A. Phillips, UC IPM Program, UC Cooperative Extension, Ventura County
C. E. Kallsen, UC Cooperative Extension, Kern County
D. R. Haviland, UC Cooperative Extension, Kern County
Acknowledgments for contributions to Insect, Mites, and Snails:
J. Barcinas, E. S. I., Corona, CA
R. Dunn, Badger Farming County, Exeter, CA
J. Gorden, Pest Management Associates, Exeter, CA
H. Griffiths, E. S. I., Corona, CA
D. Machlitt, Consulting Entomology Services, Moorpark, CA
C. Musgrove, retired entomologist, Riverside, CA
K. Olsen, S & J Ranch, Pinedale, CA
T. Roberts, E. S. I., Corona, CA
J. Stewart, Pest Management Associates, Exeter, CA
P. Washburn, Washburn & Sons Citrus Pest Control, Riverside, CA
K. Godfrey, USDA Biological Control, Sacramento
D. Headrick, California Polytechnic State University, San Luis Obispo
B. Faber, UC Cooperative Extension, Ventura County
J. Kabashima, UC Cooperative Extension, South Coast Research and Extension Center

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