How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PESTS

Wireworms are the soil-dwelling larvae of the click beetle. They are shiny, slender, cylindrical, hard-bodied, wirelike, yellow-to-brown larvae found at all times of the year and in almost any kind of soil. The larval (or wireworm) stage of this beetle may last several years.

DAMAGE

Wireworm larvae injure crops by devouring seeds in the soil, thus preventing seedlings from emerging. They also cause damage by cutting off small, underground stems and roots; and by boring in larger stems and roots.

MANAGEMENT

Wireworms may be a problem following an alfalfa rotation or in fields that were previously pastures. Cultivating, flooding, and dry fallowing can help reduce populations.

The presence of wireworm larvae can be monitored by burying carrot pieces partially into the soil at seeding to attract the wireworms. If wireworms are present, a preventive seed treatment may be necessary.

Start inspecting plants for wireworm damage along with other pests and their damage when the crop emerges. Often the wireworm will be found near the damaged or missing seed or plant. Consider using treated seed in fields with a history of wireworm problems.

Common name		Amount/Acre**	R.E.I.+	P.H.I.+
(trade name)			(hours)	(days)
When choosing a pesticide, consider information relating to natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A.	IMIDACLOPRID
	(Admire Pro)	7–10.5 fl oz	12	21
	MODE OF ACTION GROUP NUMBER1: 4A
	COMMENTS: A soil application, may also be applied in irrigation water. Apply before or at planting when monitoring suggest wireworms could be a problem.
**	See label for dilution rates.
+	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 until harvest can take place. In some cases the R.E.I. exceeds the P.H.I. The longer of these two intervals is the minimum time that must elapse before harvest may take place.
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: Dry Beans
UC ANR Publication 3446
Insects and Mites
L. D. Godfrey, Entomology, UC Davis
R. F. Long, UC Cooperative Extension, Yolo County

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