How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PESTS
Darkling beetles (tenebrionids) are dull bluish black or brown, and about 0.25 inch long. The tips of their antennae are often enlarged, distinguishing them from predaceous ground beetles (carabids), which are beneficial.

DAMAGE

These beetles chew off seedlings or feed on foliage. Damage often begins on field edges because this pest usually invades from weeds or adjacent crops. Darkling ground beetles are most active at night.

MANAGEMENT

Cultural Control
A ditch filled with water can prevent invasions from adjacent fields.

Organically Acceptable Methods
Cultural controls are organically acceptable.

Management Decisions
If chewed-off seedlings are found, and darkling ground beetles are present, apply an insecticide. A bait placed around the edge of field is usually sufficient.

Common name		Amount/Acre**	R.E.I.+	P.H.I.+
(trade name)			(hours)	(days)
When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A.	CARBARYL
	(Sevin Bait 5%)	40 lb	12	see label
	MODE OF ACTION GROUP NUMBER1: 1A
B.	CYPERMETHRIN*
	(Ammo)	Label rates	12	5
	MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: For use on head lettuce only. Apply through chemigation.
C.	PERMETHRIN*
	(Ambush, Pounce)	Label rates	12	1
	MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: Do not use if leafminers are present.
D.	ESFENVALERATE*
	(Asana XL)	Label rates	12	7
	MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: For use on head lettuce only. Do not use if leafminers are present.
**	Mix with enough water to provide complete coverage.
+	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/.

PUBLICATION

UC IPM Pest Management Guidelines: Lettuce
UC ANR Publication 3450
Insects and Other Arthropods
E. T. Natwick, UC Cooperative Extension, Imperial County
Acknowledgment for contributions to Insects and Mites:
W. E. Chaney, UC Cooperative Extension, Monterey County
N. C. Toscano, Entomology, UC Riverside

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