Navel orangeworm, a primary tree nut pest, can cause large losses in yield and profit if not managed effectively.

A primary pest of almonds, pistachios and walnuts, navel orangeworm is small but mighty. With a strong management plan in place from the mummy nut phase through harvest, you can protect your tree nuts and maximize yield potential.

Dennis H. Tootelian, Ph.D., economist from Sacramento, CA, estimates that pistachio growers will spend $1.8 billion in total on navel orangeworm management in the next 5 years. Implementing an effective management plan for navel orangeworm that also controls secondary pests, like spider mites and peach twig borer, is crucial to ensure dollars invested are maximized to protect orchards.

The key to managing and preventing further infestation of damaging pests is to get ahead of them early with a May – or mummy – spray and continue to treat orchards every 2-3 weeks.

Effectively managing navel orangeworm will be critical in the coming years as Jhalendra Rijal, UC Agriculture and Natural Resources integrated pest management advisor, predicts that by 2050 there will be a fifth generation of navel orangeworm each season. The climate model from Rijal’s research suggests that by 2050, spring temperatures will start earlier, meaning insect activity will also start earlier, and with increased temperatures continuing throughout the season, the number of days needed to complete a generation will be reduced. Research also shows that insects that have a shorter generation time can increase their population numbers faster and can develop resistance to insecticides more quickly. With an extra generation of navel orangeworm to worry about each season, your almond, walnut and pistachio orchards will be at a higher risk of potential crop damage and economic loss, making integrated pest management measures and effective insecticide applications crucial in future seasons.

Hull split is another critical time for pest control. This is when nuts are most vulnerable to damage from pests, as the exposed nut gives navel orangeworm and secondary insects access to the nutmeat inside. Larvae bore into the nutmeat of almonds and other tree nuts, and as they grow and continue to consume the nutmeat, the pests produce large amounts of webbing and frass which leads to fungal infections and contamination.

With a trio of powerful insect control tools, growers and consultants can execute a customized management plan to stay ahead of navel orangeworm and secondary pests for higher yield potential in orchards.

• Minecto® Pro is a broad-spectrum foliar insecticide that controls navel orangeworm and other damaging secondary pests, including mites in tree nuts. Flexible enough to fit into any management plan, complementary ingredients cyantraniliprole and abamectin combine to form a convenient premix formulation that protects against multiple overlapping pest populations to meet the needs your orchard demands.
• Besiege® insecticide provides dual-action protection against the most difficult lepidopteran pests, including navel orangeworm, peach twig borer, codling moth, leaffooted plant bug and walnut husk fly. With long-lasting residual and outstanding knockdown, Besiege is ideal for application at hull split.
• With a unique mode of action for control against navel orangeworm larvae, Proclaim® insecticide is rapidly absorbed into the leaf to offer knockdown activity against adults and mite suppression for 2-3 weeks after application.

Minecto Pro provides powerful control of a broad-spectrum of pests, including navel orangeworm, peach twig borer and oriental fruit moth, in tree nut orchards, resulting in a lower percentage of nuts damaged.

The use of strong insecticides, like Besiege, helps growers prevent navel orangworm damage in their almond orchards.

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