Navel Orangeworm (Amgelous transitella) is a serious insect pest of almonds. For greater detail on the life cycle of Navel Orangeworm (NOW) click on the University of California IPM web site.

Goniozus legneri are predators of NOW. The female wasps stings and kills the NOW larvae. The end result is a dead larvae. For a picture of the Goniozus wasp, click on the picture from the University of California IPM web site.

Effective management of Navel Orangeworm (NOW) is based upon Four Steps as follows:

1 - Winter sanitation

Winter sanitation involves the following activities. Shaking the tree again, polling the limbs and shredding the mummy nuts that fall to the ground. Some growers shake the tree, some growers poll the tree. Either method is fine. All growers should shred the mummy nuts once they are on the ground. Winter sanitation is the most important step in NOW management. Never skip this step !

Click to see stages of Goniozus wasp!

 

2 - Post-Harvest Release of Goniozus legneri

Once the first soft shell (usually Non-Pareil) nuts have been harvested (shaken, dried and picked up) the autumn release of Goniozus should occur. We recommend 1,000 to 1,500 Goniozus per acre at this time. This release reduces the number of NOW infested “Mummy” nuts left on the tree.

Trial work done by California Ag Supply showed a 400% reduction in the number of infested mummy nuts going into December. The non-treated almond had 25% NOW infested nuts. The Goniozus treated had 5%.

When doing winter sanitation 100% of the mummies are never destroyed. The use of Goniozus allows the grower to start the new season with as low a population of NOW in their field as possible.

Click to see a Goniozus wasp attack a Navel Orange worm lavae

3 - Spring release of Goniozus legneri

To kill the NOW that do make it through the winter sanitation, we recommend a release of 500 Goniozus per acre in early spring to clean up any NOW left in the orchard.

4 - Hull split pesticide application

The traditional pesticide application for Peach Twig Borer, NOW and spider mites is at hull split time. This application will kill about 50% of the NOW and is usually the last pesticide application before harvest. With only a 50% kill rate, you can see why keeping NOW number low for the hull split spray is vital.

Management of Navel Orangeworm is a year round process in almonds. Each of the 4 steps is vital to reducing your nut damage to the minimum. Goniozus legneri is a vital step in this process!

To purchase Goniozus legneri contact us at:
California Ag Supply
1908 Wedgemont Place
Bakersfield, California 93311
Tel/FAX: 661-663-9520
E-mail: goniozus@californiaagsupply.com