How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST

The adult false chinch bug is a small bug, about 0.12 inch or 3 mm long. It is gray to light brown in color and looks somewhat like a small lygus bug. The nymph is gray with a reddish brown abdomen.

False chinch bugs can occur in high numbers on weeds within or adjacent to pistachio orchards. The eggs are laid randomly on the soil or within soil cracks near weeds. The false chinch bug spends the winter primarily in the immature stage (nymph) on weeds. As weeds dry in spring or are destroyed, chinch bugs migrate to pistachio trees where they feed. Nymphs predominate during migration but adults may also be present. Important weeds that serve as hosts include wild mustard, wild radish, shepherd's-purse, and London rocket. The most serious infestations result from spring migrations; however, fall migrations can also occur. Movement occurs in early morning or evening.

DAMAGE

False chinch bugs can be a serious problem on newly planted pistachio trees, especially when cardboard trunk guards are used, which shelter the bugs during the day. Their feeding can cause young trees to wilt and die. Feeding on older trees can cause leaves to drop.

MANAGEMENT

On newly planted trees, if bugs are so numerous that wilting is evident, a treatment is warranted. Treat either in the evening or early morning when chinch bugs are active.

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 and environmental impact.
A.	PERMETHRIN*
	(Pounce) 3.2EC	8–16 oz	12	0
	(Ambush) 25WP	12.8–25.6 oz	12	0
	MODE OF ACTION GROUP NUMBER1: 3
	COMMENTS: Do not apply more than 0.8 lb a.i./acre/season for 25W formulation and 1.6 lb a.i./acre/season for 3.2 EC formation.
**	Unless otherwise noted, apply with enough water to ensure adequate 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: Pistachio
UC ANR Publication 3461
Insects and Mites
W. J. Bentley, Kearney Agricultural Center, Parlier
R. H. Beede, UC Cooperative Extension, Kings County
K. M. Daane, Biological Control, UC Berkeley/Kearney Agricultural Center, Parlier
D. R. Haviland, UC Cooperative Extension, Kern County
Acknowledgment for contributions to Insects and Mites:
R. E. Rice, Kearney Agricultural Center, Parlier

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