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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Commodity Protection and Quality Research » Research » Publications at this Location » Publication #377270

Research Project: Systems-Based Approaches for Control of Arthropod Pests Important to Agricultural Production, Trade and Quarantine

Location: Commodity Protection and Quality Research

Title: Biology and management of navel orangeworm (Lepidoptera: Pyralidae) in California

item WILSON, HOUSTON - University Of California
item Burks, Charles - Chuck
item REGER, JOSHUA - University Of California
item WENGER, JACOB - University Of California

Submitted to: Journal of Integrated Pest Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2020
Publication Date: 12/25/2020
Citation: Wilson, H., Burks, C.S., Reger, J.E., Wenger, J.A. 2020. Biology and management of navel orangeworm (Lepidoptera: Pyralidae) in California. Journal of Integrated Pest Management. 11(1):1-15.

Interpretive Summary: The navel orangeworm has been a key pest of California tree nuts for over 60 years. Expansion and changes in the tree nut industries have resulted in support for ongoing research into the biology and control of this moth; these historic and recent trends are summarized in this review. Recent changes in management of this pest have included the availability of mating disruption and pheromone lures, and continuing research in alternative attractants as widespread adoption of mating disruption has made pheromone lure less useful. Challenges for control of navel orangeworm include a wide host range, a strong dispersal capacity, difficulty in prediction of damage, and a low tolerance for damage in these high-value commodities. These factors, along with increasing adoption of mating disruption and pilot scale research into use of sterile insect technique, have increased interest in area-wide coordination of navel orangeworm pest management. The information in this review will help applied researchers, extension personnel, and crop and pest managers promote profitability and environmental sustainability while managing this key pest of walnuts, almonds, and pistachios grown on over 1.5 million acres of land and worth >$8 billion annually unprocessed.

Technical Abstract: Navel orangeworm, Amyelois transitella (Walker), is a primary pest of almonds, pistachios, and walnuts in California. These specialty tree nut crops are widely planted across the state and account for a significant share of total agricultural revenue, with 1.7 million combined acres generating a total farm-gate value of $8.9 billion. Larvae of A. transitella cause direct damage to the nut, burrowing into the kernel and contaminating it with frass and webbing, while adults are able to introduce fungi during oviposition that produce aflatoxin, a known human carcinogen that is heavily regulated both domestically and in key foreign markets. As such, there is little tolerance for A. transitella infestation, and most operations aim for <2% crop damage from this pest. Currently, integrated management of A. transitella involves a combination of orchard sanitation, well-timed insecticide sprays, timely harvest and, most recently, mating disruption. Additional novel tools, such as sterile insect technique, are currently being explored. This species has a strong dispersal capacity, and given the extensive, and many times contiguous, acreage of tree nuts in California, long-term management will require the development of an effective area-wide management strategy. Here we discuss the biology, seasonal phenology, monitoring, and management of A. transitella across almonds, pistachios and walnuts.