How to Manage Pests

UC Pest Management Guidelines

Cherry

Green Fruitworms

Scientific Names: Orthosia hibisci, Amphipyra pyramidoides, Xylomyges curialis, and others

(Reviewed 11/09, updated 11/09)

In this Guideline:

DESCRIPTION OF THE PESTS

Larvae are pale green, often with whitish stripes down each side of the body and a narrow stripe down the middle of the back. The adult of one common species is a grayish moth with a 1-inch wingspan. Most species overwinter as pupae (except Amphipyra, which overwinters in the egg state). All species have one generation each year, but because egg hatch occurs over an extended period in spring, all sizes of larvae may be present at the same time.

Damage

Larvae eat large holes in young leaves and fruit. Fruit damage usually begins after petal fall.

Management

Regular monitoring each spring during bloom and after is important so that prompt action can be taken if damaging populations develop. For more information, see MONITORING PESTS AT BLOOM.

Biological Control

Certain parasitic wasps (Apanteles, Eulophus, Meteorus, and Ophion spp.) help keep green fruitworm populations under control.

Organically Acceptable Methods

Sprays of Bacillus thuringiensis and the Entrust formulation of spinosad are acceptable for use on an organically certified crop.

Monitoring and Treatment Decisions

Check the orchard in early spring for presence of larvae and feeding damage. When larval damage is evident in the orchard, apply an insecticide shortly after petal fall.

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.
PETAL FALL TO PREHARVEST
A.	METHOXYFENOZIDE
	(Intrepid) 2F	16 fl oz	4 fl oz	4	7
	MODE-OF-ACTION GROUP NUMBER1: 18A
	COMMENTS: Most effective when applied at petal fall. Do not apply more than 16 fl oz/acre/application or 58 fl oz/acre/season. Coverage is extremely important; sprayer speed should not exceed 2 mph.
B.	BACILLUS THURINGIENSIS ssp. KURSTAKI#
	(various products)	Label rates		4	0
	MODE-OF-ACTION GROUP NUMBER1: 11.B2
	COMMENTS: Least harmful to beneficials. Bt is a stomach poison and must be consumed by the leafroller; therefore it is most effective when applied during warm, dry weather when larvae are actively feeding. Most effective against young larvae. Requires more than 1 treatment; apply second application 7-10 days after first.
C.	SPINOSAD
	(Entrust)#	1.71-2.5 oz	0.43-0.6 oz	4	7
	MODE-OF-ACTION GROUP NUMBER1: 5
	COMMENTS: Most effective when applied at petal fall. This product is toxic to bees for 3hours following treatment; apply in late evening after bees have stopped foraging. Do not apply more than 9 oz/acre/year.
D.	SPINETORAM
	(Delegate) WG	4.5-7 oz	1.125-1.75 oz	4	7
	MODE-OF-ACTION GROUP NUMBER1: 5
E.	CHLORANTRANILIPROLE
	(Altacor)	3-4.5 oz	0.75-1.125 oz	4	10
	MODE-OF-ACTION GROUP NUMBER1: 28
	COMMENTS: Do not use with an adjuvant. A newer material; impact on beneficials not yet determined. May cause mite flare ups.
F.	FLUBENDIAMIDE
	(Belt) SC	3-4 oz	0.75-1 oz	12	7
	MODE-OF-ACTION GROUP NUMBER1: 28
	COMMENTS: A newer material; impact on beneficials not yet determined. Highly toxic to honey bees.
G.	CARBARYL*
	(Sevin) XLR PLUS	4 qt	1 qt	12	1
	MODE-OF-ACTION GROUP NUMBER1: 1A
	COMMENTS: May cause increased spider mite problems. Do not apply more than 14 qt XLR PLUS/acre/season. The XLR PLUS formulation is less hazardous to honey bees than other formulations if applied from late evening to early morning when bees are not foraging.
**	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/.
#	Acceptable for organically grown produce.

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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