Pest Archives - West Coast Nut



Gains Being Made in SIT NOW Research

Hopes that sterile insect technology (SIT) can offer a viable alternative for controlling navel orangeworm (NOW) in tree nut crops appear to have undergone a reversal of fortune as researchers were able to dramatically improve trial results between 2018 and 2019. “After the initial field trials in 2018, we realized we were facing a lot of challenges with these sterile NOW,” said Houston Wilson, a Cooperative Extension Specialist with the Department of Entomology at University of California Riverside, who is leading the research along with Chuck Burks, a research entomologist at USDA-ARS in Parlier, California. “As we go into 2020, it now feels like we have a lot clearer idea of what specific issues need to be addressed.” In 2019, the second year of releasing irradiated moths into pistachio orchards, Wilson said researchers documented significantly improved sterile moth recovery rates – a key indicator of moth performance in the field...

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Identifying Rodents is the First Management Step in Tree Nut Orchards

Vertebrate pests chew the bark on young trees, create extensive burrow systems that pose problems with equipment movement and worker safety, damage irrigation lines and in extreme situations, affect crop yields. Roger Baldwin, UCCE wildlife specialist, said that correct identification of the problem species is the first step in controlling populations. What may work for ground squirrel control won’t be as effective against a vole invasion. Understanding biology and habitat of the target species will help with choosing the most effective control strategies. Identify the Pest California ground squirrels are a common pest in many tree nut orchards. They are a social, diurnal species that can girdle young trees, chew irrigation lines and cause crop losses. Baldwin, in a presentation at Pistachio Day 2020, said these mottled grey-brown rodents live in burrows that are normally two-three feet below ground. Ground squirrels are active during the day and have two periods...

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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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