How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST
Peach silver mites are tiny, four-legged eriophyid mites, yellow to pinkish white, and somewhat wedge shaped, being broadest just behind the anterior end. Because they are so tiny, they are difficult to see without a hand lens of at least 10x power.

Peach silver mites overwinter as females in bark crevices, around buds, and under bud scales. They move to leaves soon after budbreak in spring. These mites can also be found on small fruit, often inhabiting the area between the calyx and the fruit. Later in the season they are found primarily on the lower leaf surface. Before leaf fall, females move to overwintering sites. Many generations are produced during the season.

DAMAGE

On rare occasions when very high populations of peach silver mite survive the winter, they produce symptoms on the unfolding leaves. Symptoms consist of minute, yellow spots and a tendency for the leaf edges to curl toward the midrib. Ordinarily, however, most injury is not noticed until mid- to late summer when heavily infested leaves take on a silvery appearance.

MANAGEMENT

Treatments applied specifically for control of peach silver mite are rarely needed and should be avoided because peach silver mites serve as early season food for predaceous mites, which in turn aid in reducing populations of other pest mites. The use of broad-spectrum insecticides for other pests can cause high infestations of peach silver mite.

Organically Acceptable Methods
Sulfur sprays are acceptable for organically certified crops, but will reduce predator mite populations.

Monitoring and Treatment Decisions
If heavy populations (200–300 per leaf) of peach silver mite are present and causing damage, consider applying sulfur or miticides used for control of other mite species. Some insecticides applied for control of other pests eliminate peach silver mites as well.

Common name		Amount/Acre**		R.E.I.+	P.H.I.+
(trade name)		(conc.)	(dilute)	(hours)	(days)
When choosing a pesticide, consider information relating to impact on natural enemies and honey bees, the impact of the timing on beneficials, and environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A.	WETTABLE SULFUR#	—	5 lb	24	0
	MODE OF ACTION: Unknown. An inorganic miticide.
	COMMENTS: Do not apply within 2 weeks of oil spray. May reduce predator mite populations.
**	For dilute applications, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate applications, use 80-100 gal water/acre, or lower if label allows.
#	Acceptable for use on organically grown produce.
—	Not recommended or not on 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.

PUBLICATION

UC IPM Pest Management Guidelines: Nectarine
UC ANR Publication 3451
Insects and Mites
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
K. R. Day, UC Cooperative Extension, Tulare County
Acknowledgment for contributions to Insects and Mites:
R. E. Rice, Kearney Agricultural Center, Parlier

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