How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST

The black cherry aphid is large and shiny metallic black. This pest overwinters as shiny black eggs on twigs and fruit spurs. Eggs hatch shortly before bloom and the aphids can go through a number of generations and may become very abundant in early spring. The population decreases to a very low level on cherry trees during the summer months and primarily survives on mustard family weeds during this period.

DAMAGE

High populations of the black cherry aphid are mainly a problem on young trees where they cause curling and distortion of the leaves.

MANAGEMENT

The best time to control black cherry aphid is during the dormant or delayed dormant period. In addition, a number of natural enemies, including lady beetles, lacewings, and several species of parasitic wasps, help keep aphid populations controlled. Assess populations at bloom. If control has not been achieved during the dormant period and natural enemies are not adequately controlling the population, apply a treatment shortly after petal fall.

Common name		Amount to Use**		R.E.I.+	P.H.I.+
(trade name)		(conc.)	(dilute)	(hours)	(days)
The following materials are listed in order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies and honey bees. When choosing a pesticide, also consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used.
DORMANT or DELAYED DORMANT
A.	NARROW RANGE OIL	4–8 gal	1.5–2 gal	see label	0
	MODE OF ACTION: Improves translaminar movement and insecticide persistence.
	. . . PLUS . . .
	METHIDATHION*
	(Supracide) 25W	4–8 lb	1–2 lb	3 days	see comments
	MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: Apply before blossoms open or injury may result. Do not make more than one application per crop season. Pyrethroids applied at this time can be disruptive to beneficials.
	. . . or . . .
	DIAZINON* 50WP	4 lb	1.25 lb	4 days	21
	MODE OF ACTION GROUP NUMBER1: 1B
	COMMENTS: Organophosphate insecticides used during delayed dormancy are very toxic to honey bees. Remove bees from orchard if cover crops or weeds are in bloom. Oil sprays may injure trees that are water stressed. It is advisable to postpone an oil application to water-stressed trees until winter rains have replenished soil water and the tree bark is noticeably moist. Avoid drift and runoff into surface water or choose alternative materials. Diazinon has been found in surface waters at levels that violate federal and state water quality standards.
	. . . or . . .
	CHLORPYRIFOS*
	(Lorsban Advanced, 4EC)	2 qt	0.5 qt	4 days	see comments
	MODE OF ACTION GROUP NUMBER1: 1B
	COMMENTS: Most effective during delayed dormancy. Be sure to apply before blossoms open or injury may occur. Do not graze livestock in treated areas or feed them treated cover crops. Avoid drift and runoff into surface water or choose alternative materials. Chlorpyrifos has been found in surface waters at levels that violate federal and state water quality standards.
PETAL FALL
A.	IMIDACLOPRID
	(Provado) 1.6F	8 oz	2 oz	12	7
	MODE OF ACTION GROUP NUMBER1: 4A
B.	THIAMETHOXAM
	(Actara) 25WDG	4 oz	1 oz	12	14
	MODE OF ACTION GROUP NUMBER1: 4A
	COMMENTS: May only be applied once after bloom. Do not apply by air.
C.	ACETAMIPRID
	(Assail) 30SG	2.5-5.3 oz	0.625-1.325 oz	12	7
	MODE OF ACTION GROUP NUMBER1: 4A
D.	DIAZINON* 50WP	3 lb	1 lb	4 days	21
	MODE OF ACTION GROUP NUMBER1: 1B
	COMMENTS: 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/.

IMPORTANT LINKS

• Photos of natural enemies of aphids

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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