How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PESTS

Several species of leafhoppers are found in dry beans with Empoasca fabae and E.solana being the most common. 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 [3 mm] long), bright green, wedge-shaped insects. 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.

DAMAGE

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.

MANAGEMENT

Start inspecting plants for leafhopper damage along with other pests and their damage during the vegetative growth period. Continue looking through the flower bud-to-bloom and pod fill periods. Look for plant damage and Empoasca leafhoppers on the undersides of leaves. Examine a minimum of 10 leaves from 10 plants in at least four areas of the field. Measurable thresholds are not available.

Common name		Amount/Acre**	R.E.I.+	P.H.I.+
(trade name)			(hours)	(days)
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.
A.	DIMETHOATE
	2.67 lb/gal EC	1–1.5 pt	48	0
	MODE OF ACTION GROUP NUMBER1: 1B
	COMMENTS: Ground or air application. Do not feed treated vines to livestock. Use of product may result in mite outbreak. Highly toxic to honey bees; do not apply when bees are present.
B.	ACEPHATE
	(Orthene) 75SP	0.67 lb	24	14
	MODE OF ACTION GROUP NUMBER1: 1B
	COMMENTS: Use of product may result in mite outbreak. Highly toxic to honey bees; do not apply when bees are present.
**	Mix with sufficient water to obtain full coverage.
+	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.
1	Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.

PUBLICATION

UC IPM Pest Management Guidelines: Dry Beans
UC ANR Publication 3446
Insects and Mites
L. D. Godfrey, Entomology, UC Davis
R. F. Long, UC Cooperative Extension, Yolo County

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