University of California

Postharvest survival of navel orangeworm assessed in pistachios


Joel P. Siegel
L.P.S. (Bas) Kuenen
Bradley S. Higbee
Patricia Noble
Richard Gill
Glen Y. Yokota
Rodrigo Krugner
Kent M. Daane

Authors Affiliations

J.P. Siegel is Research Entomologist, L.P.S. (Bas) Kuenen is Research Entomologist, and P. Noble and R. Gill are Biological Science Technicians, U.S. Department of Agriculture Agricultural Research Service (USDA ARS), San Joaquin Valley Agricultural Sciences Center, Commodity Protection and Quarantine Research Unit, Parlier; B.S. Higbee is Research Entomologist, Paramount Farming Company, Bakersfield; G.Y. Yokota is Staff Research Associate, R. Krugner was Laboratory Assistant, and K.M. Daane is UC Cooperative Extension Specialist, Department of Environmental Science, Policy and Management, UC Berkeley (currently, R. Krugner is Research Entomologist, USDA ARS, San Joaquin Valley Agricultural Sciences Center). The authors gratefully acknowledge the help of James Bettiga of S&J Ranch and Mike Braga of Nichols Farm for providing field sites, and thank anonymous reviewers for comments on the manuscript. This research was funded in part by the California Pistachio Commission.

Publication Information

Hilgardia 62(1):30-35. DOI:10.3733/ca.v062n01p30. January 2008.

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Controlling navel orangeworm, a key pistachio pest, is problematic because the moth overwinters in “mummy” nuts. After harvest, there may be more than 30,000 pistachio nuts (mummies) left behind per acre. To provide better information for winter sanitation decisions, we investigated the number of available mummies and their levels of navel orangeworm infestation from winter through early summer in California pistachio orchards. Navel orangeworm mortality was highest from late December through mid-February, and was also higher on the ground than in trees. Mortality on the ground was highest when mummies were tilled or mowed with the groundcover than when nuts were left on the raised berm. Our data indicates that, in contrast to almonds, it is more productive to focus on clearing pistachios from the ground than on removing them from trees. However, winter sanitation procedures also should be augmented in order to destroy more overwintering navel orangeworm.


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Siegel J, Kuenen L, Higbee B, Noble P, Gill R, Yokota G, Krugner R, Daane K. 2008. Postharvest survival of navel orangeworm assessed in pistachios. Hilgardia 62(1):30-35. DOI:10.3733/ca.v062n01p30
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