Pest Management Science (2022) 78, 2034-2042

Joel P. Siegel and Garrett Gilcrease (2022)
Augmenting sanitation with insecticides to improve control of navel orangeworm (Amyelois transitella Walker) (Lepidoptera: Pyralidae) in California tree nuts
Pest Management Science 78 (5), 2034-2042
Abstract:
BACKGROUND
Sanitation, consisting of eliminating unharvested nuts (mummies) that serve as both harborage and food source for navel orangeworm (Amyelois transitella), is the foundation for control in almonds and pistachios. Sometimes sanitation is ineffective and needs to be augmented. Trials in almonds and pistachios were conducted early October 2005–2006 to determine if insecticides applied postharvest could augment sanitation, and in almonds late March to early May 2016–2020 to establish their duration of control.
RESULTS
Early October sprays reduced adult emergence by as much as 81.5% in pistachios, but reduction was only 32.4% in almonds. Trapping before almond hull split revealed that 55% of adult emergence occurred between 15 April and 1 June, indicating that an insecticide with a six week duration of control could reduce successful oviposition and neonate establishment. Five insecticides applied from late March to early May belonging to four Insecticide Resistance Action Committee (IRAC) groups decreased survival for at least six weeks, and some lasted as long as 10 weeks. By contrast, the duration of control in contact bioassays was far shorter.
CONCLUSION
Insecticides applied from late March to early May successfully reduced the survival of A. transitella in almond mummies for as long as 10 weeks postapplication, and there was a positive relationship between reduction in survival and kernel damage. If these insecticides are applied during mid- to late April, postbloom and before hull split, they can substantially eliminate almond mummies as a resource for 55% of the spring flight of A. transitella.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Joel P. Siegel

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Amyelois transitella	Almond (Prunus dulcis)	U.S.A. (SW)
	Amyelois transitella	Pistachio nut and relatives (Pistacia)	U.S.A. (SW)