How to Manage Pests

UC Pest Management Guidelines

DESCRIPTION OF THE PEST

Adults are dark brown, compact weevils up to about 0.5 inch long with longitudinal striations. They are flightless and nocturnal, hiding at the base of fruit or under dirt clods during the day and crawling up the tree at night to feed. Larvae are white, legless grubs that feed on tree roots. Adult emergence often begins in May, and adults are present all summer. There is one generation per year.

DAMAGE

Adults feed on foliage, notching out the edge of the leaves, giving them a ragged appearance. Under high population pressure, only the mid-vein of the leaf will remain. Adult feeding on the bark of young twigs may cause dieback. Mature trees can withstand attack without significant damage; however, feeding before harvest may damage fruit stems. Replanted trees may be severely defoliated and die. No damage has been associated with larval feeding.

MANAGEMENT

To reduce damage on young trees that are infested, apply a 3- to 4-inch band of sticky material on the trunk of young trees to trap crawling adults in May when the first adult feeding is observed. Apply Stickem or Tanglefoot over a special tape or painted areas of the trunk of young trees to prevent bark damage. Reapply the sticky material when it becomes dirty or loses its effectiveness. Alternatively, some growers have had success with an insecticide treatment applied at night when the insects are exposed, but research has not been done to verify this.

Common name		Amount to Use**		R.E.I.+	P.H.I.+
(trade name)		(conc.)	(dilute)	(hours)	(days)
When choosing a pesticide, take into account efficacy and impact on natural enemies and honey bees. Also consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A.	CARBARYL*
	(Sevin) 80S	3.75–5 lb	0.9375–1.125 lb	12	1
	MODE OF ACTION GROUP NUMBER1: 1A
	COMMENTS: Apply at night when insects are active and exposed may provide control; research data is lacking.
**	For concentrate applications, use the amount given in 80–100 gal water/acre, or lower if the label allows; for dilute applications, amount is per 100 gal water to be applied in 300–400 gal water/acre, according to label.
+	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: Cherry
UC ANR Publication 3440
Insects and Mites
J. A. Grant, UC Cooperative Extension, San Joaquin County
J. L. Caprile, UC Cooperative Extension, Contra Costa County
W. W. Coates, UC Cooperative Extension, San Benito County
R. A. Van Steenwyk, Insect Biology, UC Berkeley
K. M. Daane, Kearney Agricultural Center, Parlier
Acknowledgment for contributions to Insects and Mites:
J. Colyn, Mid-Valley Ag. Services
M. Devencenzi, Devencenzi Ag. Pest Mgmt. and Research
P. McKenzie, Mid-Valley Ag. Services

Top of page