How to Manage Pests

UC Pest Management Guidelines

Cherry

Mountain Leafhopper

Scientific Name: Colladonus montanus

(Reviewed 11/09, updated 11/09)

In this Guideline:

DESCRIPTION OF THE PEST

The mountain leafhopper is a slender, dark brown leafhopper with red eyes and a yellow band behind the head, and a yellow spot in the center of each wing. The leafhopper overwinters on herbaceous vegetation like alfalfa, clovers, and weedy sugarbeet fields. When fields are harvested in spring, the leafhopper disperses to adjacent orchards and can be widely distributed throughout an orchard within a few days. A second peak of leafhoppers may be seen in late July. This leafhopper does not prefer cherry trees, but breeds on weeds (curly dock, California burclover, sweetclovers) on the orchard floor.

Damage

This leafhopper is a concern because it vectors the pathogen that causes X-DISEASE (aka cherry buckskin). It acquires the disease agents by feeding on diseased cherry trees or infected weeds such as clover. It then may infect healthy cherry trees.

Management

Treat immediately after harvest and at 4- to 6-week intervals thereafter. Length of interval depends on residual effectiveness of material used. Remove buckskin-diseased trees immediately after treatment so that the leafhoppers are destroyed before trees are removed.

Common name		Amount to use**		R.E.I.‡	P.H.I.‡
(trade name)		(conc.)	(dilute)
				(hours)	(days)
The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, the pesticide's properties, and application timing. Not all registered pesticides are listed. Always read the label of the product being listed.
POSTHARVEST
A.	ESFENVALERATE*
	(Asana XL) 0.66EC	4.8-14.5 oz	2.0-5.8 oz	12	14
	MODE-OF-ACTION GROUP NUMBER1: 3
	COMMENTS: Provides long-term control. May cause serious outbreaks of spider mites. Do not exceed 0.375 lb a.i./acre/season. At 10 oz/acre has a 4-week residual; at 14 oz/acre has a 6-week residual.
B.	LAMBDA-CYHALOTHRIN*
	(Warrior II with Zeon)	1.28-2.56 fl oz	0.32-0.84 fl oz	24	14
	MODE-OF-ACTION GROUP NUMBER1: 3
C.	THIAMETHOXAM
	(Actara) 25WDG	5.5 oz	1 oz	12	14
	MODE-OF-ACTION GROUP NUMBER1: 4A
	COMMENTS: May only be applied once after bloom. Do not apply by air. Has a 4-week residual at the highest label rate.
D.	DIAZINON* 50WP	2 lb	0.5 lb	4 days	21
	MODE-OF-ACTION GROUP NUMBER1: 1B
	COMMENTS: Provides only immediate control. No control 2 days after application. Avoid drift and tailwater runoff into surface waters. Where cherries are grown adjacent to waterways, do not use this material.
**	For concentrate applications, use the amount given in 80-100 gal water/acre, or lower if the label allows; for dilute applications, amount is per 100 gal water to be applied in 300-400 gal water/acre, according to label.
‡	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.
*	Permit required from county agricultural commissioner for purchase or use.
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: Cherry
UC ANR Publication 3440

Insects and Mites

• J. A. Grant, UC Cooperative Extension, San Joaquin County
• J. L. Caprile, UC Cooperative Extension, Contra Costa County
• W. W. Coates, UC Cooperative Extension, San Benito County
• R. A. Van Steenwyk, Insect Biology, UC Berkeley
• K. M. Daane, Kearney Agricultural Center, Parlier

Acknowledgment for contributions to Insects and Mites:

• J. Colyn, Mid-Valley Ag. Services
• M. Devencenzi, Devencenzi Ag. Pest Mgmt. and Research
• P. McKenzie, Mid-Valley Ag. Services

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