Pest Archives - Page 3 of 6 - West Coast Nut



NOW in Walnuts

Contiguous acreage of nut crops in California is making navel orangeworm (NOW) a more pressing pest concern for walnut growers, according to Emily Symmes, Sacramento Valley area IPM advisor with the UC Statewide IPM Program and Cooperative Extension. “Navel orangeworm has a broad host range and availability in the state, with tree nuts among the preferred hosts,” Symmes said. “And we are seeing expanded, contiguous acreage in tree nuts of almond, walnut and pistachio, up nearly 50 percent in bearing acreage over the last decade.” The contiguous acreage makes NOW movement and spread a significant threat to nut crops. “What we (researchers) did is we mapped the walnut, almond and pistachio acreage in the state,” Symmes said. “In the Central Valley we see this expanding continuous acreage of nut crops prime for NOW.” She explained this pattern creates a staggered crop phenology, “which means we have this continuing available host...

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Top Insects Plaguing California

Panelists at the first annual Crop Consultant Conference addressed insect pests that are the most economically damaging in specialty crops including tree nut crops. Control of these insect pests, said Kern County University of California Cooperative Extension (UCCE) farm advisor David Haviland, requires a game plan. Navel Orangeworm The number one insect pest in nut crops, navel orangeworm (NOW), is vulnerable over winter surviving inside mummy nuts left behind after harvest. Winter sanitation of orchards, by shaking mummies, blowing them to the row middles and shredding them is considered the most important strategy in NOW control. The integrated pest management (IPM) plan for control from spring through harvest, Haviland said, is to confuse winter survivors with mating disruption, protect the crop from damage with insecticide sprays in June and try for early harvest to minimize crop damage. A second shake of pollinator varieties should be done by early September to...

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A New Approach to IPM

There is a new approach to integrated pest management said Dr. Surendra K. Dara, University of California Cooperative Extension (UCCE) entomology and biological advisor and speaker at the inaugural Crop Consultant Conference. The Journal of Integrated Pest Management published Dara’s work on The New IPM Paradigm for the Modern Age earlier this year. In his paper, Dara writes that the concept of IPM is not new and has historically been based on ecological and economic aspects of pest management. The new model, Dara said, is expanded to include management, business, and sustainability while emphasizing the importance of research and public outreach. The new IPM model is economically viable, environmentally sustainable and socially acceptable. Balanced Ecology with Economics Dara said that traditionally, IPM has balanced ecology with economics. The shift places more emphasis on ecology. Pest management decisions have to make economic sense, he said, but now there are more factors...

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Walnut Pest Management: Walnut Husk Fly & Pacific Flatheaded Borer

It seems that growers are always battling pests in order to protect their crops. While we looked into navel orangeworm and codling moth in the first part of this two-part series, this second part shines the light on walnut husk fly and the Pacific flatheaded borer. So just how concerned should a walnut grower be about these pests? They don’t require equal interest, as one is more of a concern than the other. Walnut Husk Fly About the size of a housefly, and far more colorful, the walnut husk fly has one generation per year, in which female flies lay eggs beneath the surface of the walnut husk. The first sign of infestation is a point-sized, stinglike mark on the husk. And while it might initially be an easy miss, the husk will eventually show black marks as the eggs hatch and the maggots feed and destroy it. After feeding,...

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Increasing Evidence of Pacific Flatheaded Borer Attack in Walnut Orchards in California

Background and Pest Status Flatheaded borer is a larval stage of one specialized group of beetles (Insect family-Buprestidae), which are glossy iridescent colors. The name ‘flatheaded’ comes from the enlarged and flattened shape just behind the head of the larval stage (Fig. 1) of the beetle (Fig. 2), and the flatheaded borer species that has become a major issue in walnuts is Pacific flatheaded borer (PFB), Chrysobothris mali, which is known to present in the western states such as Washington, Utah, Oregon, California. A similar type of borer species causing serious damage in various nurseries and other fruit and trees in the eastern part of the United States is called Appletree flatheaded borer, Chrysobothris femorata. (more…)

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