UC IPM: UC Management Guidelines for American Plum Borer on Plum

UC Pest Management Guidelines

Plum

American Plum Borer

Scientific name: Euzophera semifuneralis

(Reviewed 5/06, updated 5/06)

In this Guideline:

Description of the pest
Damage
Management

DESCRIPTION OF THE PEST

The forewings of the adult moth are gray with brown and black markings. The wingspan is about 0.75 inch. Young larvae are white with a large, dark brown head. Mature larvae are about 1 inch long, dusky white, pinkish or dull green in color. Reddish orange frass, webbing, and gum pockets indicate their presence. They overwinter as mature larvae in a cocoon within the tree. There are three to four generations each year.

DAMAGE

Larvae bore into the tree leaving reddish orange frass and gum pockets. The boring is most damaging to the scaffold crotches or graft unions of young trees. Vigorous trees will heal over, but with heavy, prolonged infestations, scaffolds may break with wind or a heavy crop.

MANAGEMENT

Monitor young orchards in spring and summer for frass and gum pockets. If larvae are present, spray trees from 1 foot above the scaffold crotch to 1 foot below, two to three times during the growing season. The first application should be mid- to late April and subsequent applications at 6-week intervals to kill adults before they can lay eggs. Remove and destroy infested wood or heavily infested trees.

Common name

P.H.I.+

(trade name)

Amount to Use

(days)

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy, impact on natural enemies and honey bees, and impact of the timing on beneficials. When choosing a pesticide, also consider information relating to environmental impact.

DIAZINON* 50WP

1 lb/100 gal water

MODE OF ACTION: An organophosphate (Group 1B)¹ insecticide.

COMMENTS: Do not exceed 4 lb diazinon 50WP/acre.

CARBARYL*

(Sevin) 80S

3.75–5 lb/acre

MODE OF ACTION: A carbamate (Group 1A)¹ insecticide.

+	Preharvest interval. Do not apply within this many days of harvest.
*	Permit required from county agricultural commissioner for purchase or use.
¹	Modes of action are important in preventing the development of resistance to pesticides. 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. 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 is assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.

UC IPM Pest Management Guidelines: Plum
UC ANR Publication 3462
Insects and Mites
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
K. R. Day, UC Cooperative Extension, Tulare County
Acknowledgment for contributions to the insects and mites section:
R. E. Rice, Kearney Agricultural Center, Parlier

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