How to Manage Pests

UC Pest Management Guidelines

Cherry

European Earwig

Scientific Name: Forficula auricularia

(Reviewed 11/09 , updated 11/09)

In this Guideline:

Description of the Pest

Earwigs are about 0.5 inch long, shiny brown, and have a forceps-like structures at the back end of the abdomen. Earwigs are nocturnal and their presence or damage may go unnoticed until harvest. They are active year round and have two generations per year.

Damage

Earwigs feed on fruit and foliage. Foliage feeding is of little concern in mature trees; it appears as numerous, irregular holes, ragged leaf edges, or both. However, shoot-tip feeding on young trees may stunt normal growth. Earwigs feeding on fruit results in shallow, irregular holes.

Management

Management requires the removal of daytime harboring sites and prevention of access to fruit before it ripens.

Cultural Control

Keep the area at the base of trees weed-free. Keep orchard clear of prunings, loose bark, or other debris under which earwigs may nest.

Organically Acceptable Methods

Cultural controls and sprays of the Entrust formulation of spinosad are acceptable for use on organically grown cherries.

Monitoring and Treatment Decisions

Assess populations at bloom and treat at the beginning of spring activity when earwigs are found. (For more information, see MONITORING PESTS AT BLOOM.) Sprays are more effective at night when earwigs have emerged from their daytime shelters and are exposed.

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.
A.	CARBARYL*
	(Sevin) XLR PLUS	4 qt	1 qt	12	1
	MODE-OF-ACTION GROUP NUMBER1: 1A
	COMMENTS: Applications at night are most effective. Spray on trunks and crotches of trees at the beginning of spring activity. Once high populations are found in trees such an application will no longer be effective and a foliar spray is necessary. 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. May cause mite flare ups.
B.	ESFENVALERATE*
	(Asana XL) 0.66EC	4.8-14.5 oz	2.0-5.8 oz	12	14
	MODE-OF-ACTION GROUP NUMBER1: 3
	COMMENTS: Applications at night are most effective. May cause serious outbreaks of spider mites. Do not exceed 0.375 lb a.i./acre/season. At 10 oz/acre has a 4-weekresidual; at 14 oz/acre has a 6-week residual.
C.	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
	COMMENTS: Applications at night are most effective.
D.	SPINOSAD
	(Entrust)#	1.71-2.5 oz	0.43-0.6 oz	4	7
	MODE-OF-ACTION GROUP NUMBER1: 5
	COMMENTS: Applications at night are most effective. This product is toxic to bees for 3 hours following treatment; apply in late evening after bees have stopped foraging. Do not apply more than 9 oz/acre/year.
E.	SPINETORAM
	(Delegate) WG	4.5-7 oz	1.125-1.75 oz	4	7
	MODE-OF-ACTION GROUP NUMBER1: 5
**	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 use on 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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