How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST

Earwigs feed at night and can be found hidden around the crowns of the plants during the day. They are slender brown insects, about 0.5 to 0.75 inch (1.25 to 2 cm) long. They have a conspicuous pair of pincers attached to the back end of the abdomen. The adult wing covers are short and leathery. The pest becomes most destructive as nymphs approach maturity from April to July.

DAMAGE

Earwig feeding results in small deep holes in the fruit that can only be distinguished from slug damage by the absence of slime. They will also inhabit or catface open-ended fruit.

MANAGEMENT

Cultural control methods to reduce earwig damage include:

• Keeping the top of beds dry during the last irrigation, as moisture favors increased damage.
• Where practical, eliminate hiding places by removing old senescent leaves.

Check the bottom of developing fruit for damage and treat if feeding holes are present.

Common name		Amount/Acre	R.E.I.+	P.H.I+
(trade name)			(hours)	(days)
The following materials are listed in order of usefulness in an IPM program, taking into account efficacy, pesticide registrations, information related to natural enemies and honey bees, and environmental impact. Not all registered pesticides are listed. Always read the label of the product being used.
A.	CARBARYL
	(5% bait)	20 lb	12	see label
	MODE OF ACTION GROUP NUMBER1: 1A
	COMMENTS: Repeat as necessary using suitable ground or air equipment for proper distribution. Double treatment is usually more effective.
+	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.
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: Cucurbits
UC ANR Publication 3445
Insects and Mites
E. T. Natwick, UC Cooperative Extension, Imperial County
J. J. Stapleton, UC IPM Program, Kearney Agricultultural Center, Parlier
C. S. Stoddard, UC Cooperative Extension, Merced & Madera counties
Acknowledgment for contributions to Insects and Mites:
R. L. Coviello, UC Cooperative Extension, Fresno County
L. D. Godfrey, Entomology, UC Davis
C. B. Fouche, UC Cooperative Extension, San Joaquin County
C. G. Summers, Entomology, UC Davis/Kearney Agricultural Center, Parlier
J. B. LeBoeuf, AgriData Sensing, Inc., Fresno
M. Murray, UC Cooperative Extension, Colusa/Glenn counties

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