Pest Archives - West Coast Nut





Pest



A Few Arthropod Pests to Consider on Establishing Pistachio Trees

By Kris Tollerup, University of California Cooperative Extension Area-wide IPM Advisor, Kearny Agricultural Research and Extension Center, Parlier, California

The University of California (UC), Pest Management Guidelines provide recommendations for managing approximately 14 insect and mite pests on pistachio. A few of those pests, growers and pest control advisers (PCAs) should pay close attention to during the first few years while young trees establish. According to the National Agriculture Statistic Service, the industry in California has expanded by about 35 percent between 2010 and 2017 from roughly 215,000 to just over 329,000 acres. New plantings in that period ranged from 6,730 (2010) to 24,500 (2013), with acreage expanding by 18,000 in 2017. With so many acres of new pistachio trees in California, it is fitting to highlight a few economically important pests covered by the UC Pest Management Guidelines to prompt growers and PCAs to start thinking about the coming season. A group of insects important on establishing trees is the hemipterans. They have piercing-sucking mouthparts and include true...

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Update on Sterile Insect Program for Control of Navel Orangeworm

By Houston Wilson, Asst. Coop. Extension Specialist, Kearney Ag. Center, Dept. Entomology, UC Riverside
and Chuck Burks, Research Entomologist, USDA-ARS, San Joaquin Valley Agricultural Sciences Center

Sterile insect technique (SIT) makes use of large numbers of sterile insects which are released into wild populations as part of an area-wide integrated pest management (IPM) control strategy. Insects are typically mass-reared in a controlled environment and then ionizing radiation (e.g. x-rays, gamma rays) is used to induce genetic mutations that lead to sterility. The basic idea is that introduction of sterilized individuals into the wild population will limit the successful reproduction of wild individuals and lead to an overall reduction or even eradication of the target pest population (Knipling 1955). Mating with sterile individuals can reduce populations by either directly blocking reproduction or through inherited sterility in which offspring are actually produced but are themselves sterile (North 1975). Releases can include both males and females, although some programs utilize just one sex, and this is typically due to specific biological or ecological requirements.   The concept of using...

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Mating Disruption: A Crucial Tool for Nut Growers

By Kathy Coatney Editor

Mating disruption for navel orangeworm (NOW) has been widely tested throughout California with numerous research studies, and peer-reviewed research has demonstrated its efficacy. Mating disruption is a very simple process. Females emit pheromones, males use those pheromones to find the female. If an orchard is flooded with artificially produced pheromone the entire orchard smells like a female and the males struggle to find the real females. If they don’t find each other, they don’t mate, and if they don’t mate there are no eggs, no larvae, and less overall nut damage.   Mating Disruption in Almonds and Pistachios Navel orangeworm is a major and costly pest of almonds and pistachios for growers and processors. Currently, growers use winter sanitation and chemical sprays for control, but mating disruption is another important tool at their disposal. How mating disruption works is dispensers contain an artificial pheromone. They are placed in the orchard...

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pecan aphids

Insecticide Efficacy for Pecan Aphids

By Cecilia Parsons, Associate Editor

Aphid infestation and damage to pecans has become worse in the past five to six years.   Mild Winters Larry Blackwell, New Mexico State University researcher and program coordinator College of Agricultural, Consumer and Environmental Sciences, said that pecan producers in New Mexico are dealing with higher aphid numbers in their pecan orchards due to lack of freezing winter temperatures in recent years. “We have had really mild winters and thus no kill off,” said Blackwell. The high numbers of aphids in pecans is the result of the climate, and not just due to population build up, Blackwell added. This year blackmargined aphid population pressure for the first summer peak in the Mesilla Valley of southern New Mexico was high for what should be an off or lower yield year. Blackwell said pressure built in mid-May, approximately two weeks earlier than normal and populations declined at the end of June....

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Approaches to Spider Mite Management in Almonds

By Emily J. Symmes, IPM Advisor UCCE and Statewide IPM Program

Spider mites are considered indirect pests in almonds, in the sense that they do not feed directly on the harvested product. Rather, they cause injury to plants by sucking cell contents from foliage. Signs of feeding injury include leaf stippling, yellowing, and dropped leaves. High populations of mites can also be recognized by webbing on leaves and tree terminals (Image 1). Significant spider mite injury can become economic crop damage in almonds in subsequent seasons in the form of reduced vegetative tree growth and crop reduction. In addition, excessive leaf drop can interfere with harvest operations and nut drying in the current season. The most effective spider mite management programs are focused on integrating multiple tactics including cultural practices, biological control, and miticide applications when needed.   Cultural Practices Properly-irrigated, vigorous trees are less susceptible to spider mite damage. Ensure that trees are not stressed due to inadequate irrigation, fertilization,...

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