How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST

Garden symphylans are slender and white, they have 10 to 12 pairs of legs and a pair of antennae. They run rapidly when exposed to light. They occur mainly in moist soils with good structure and a high organic matter content and are often associated with debris from a previous crop that is not completely decomposed. They retreat to deeper soil levels during fallow periods and return to the root zone after crops are planted. They damage the same area every season so infestations spread slowly.

DAMAGE

Garden symphylans damage plants by feeding on roots, thus retarding plant growth. They are usually only a problem in fields that were not fumigated, or if the fumigation was ineffective.

MANAGEMENT

Soil fumigation for pathogen and weed seed control will kill symphylans. In nonfumigated fields and fields with large amounts of crop residue from a previous crop, continuous flooding for 3 weeks in the summer helps reduce infestations and discing in a crop of sorghum has been reported to reduce infestations in other crops. In organic fields, however, the best strategy is to avoid fields that have populations of symphylans in the soil.

Research from other areas of the country indicates that symphylans can be detected with bait trapping. Either carrots or potatoes can be used as the bait. Cut the bait in half longitudinally and scratch the cut surface just before placing it in a shallow hole on the soil to ensure that the surface is moist. (Be sure that when the hole is created, the soil pores/spaces aren't sealed close. Symphylans use these spaces to travel to the bait.) Cover the bait with a pot. Use at least a dozen bait traps in the field. After 2 to 5 days, examine the cut surface and the soil upon which it was resting for evidence of symphylans. If they are detected, consider a treatment. Because the recommended treatment is best applied before transplanting, bait traps for symphylans a few weeks before transplanting.

Common name		Amount/Acre	R.E.I.+	P.H.I.+
(trade name)			(hours)	(days)
When choosing a pesticide, consider information relating to impact on natural enemies and honey bees as well as the environmental impact Not all registered pesticides are listed. Always read label of product being used.
A.	DIAZINON AG 500*	1 qt	24	5
	50 WSB*	2 lb	24	5
	MODE OF ACTION GROUP NUMBER1: 1B
	COMMENTS: Broadcast before transplanting and incorporate into top 4 inches of soil. Treatment after transplanting is less effective, and material must be well watered into the soil. Do not allow this product to run off into surface waters.
B.	CHLORPYRIFOS
	(Lorsban) 75WG	2.67 lb	24	21
	MODE OF ACTION GROUP NUMBER1: 1B
	COMMENTS: Preplant incorporate. Phytotoxicity can occur when applied under high temperatures combined with drought stress. Do not make more than 2 applications of chlorpyrifos-containing products per year. Do not allow this product to run off into surface waters.
+	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: Strawberry
UC ANR Publication 3468
Insects and Mites
F. G. Zalom, Entomology, UC Davis
M. P. Bolda, UC Cooperative Extension Santa Cruz County
P. A. Phillips, UC IPM Program/UC Cooperative Extension Ventura County
Acknowledgment for contributions to the Insects and Mites:
N. C. Toscano, Entomology, UC Riverside

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