ARS | Publication request: Non-pheromonal control of navel orangeworm as a promising method toward decreasing contamination of Aspergillus flavus in California tree nuts

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 18, 2009
Publication Date: March 21, 2010
Citation: Beck, J.J., Light, D.M., Higbee, B.S., Dragull, K.D., Merrill, G.B., Gee, W.S. 2010. Non-pheromonal control of navel orangeworm as a promising method toward decreasing contamination of Aspergillus flavus in California tree nuts. American Chemical Society Abstracts.

Interpretive Summary: The navel orangeworm (NOW) is a major insect pest of California tree nuts, causing direct product loss to growers from feeding damage by the larvae. A second, in-direct damage caused by NOW is its association with the microbe Aspergillus flavus – a ubiquitous orchard fungus responsible for aflatoxin contamination of California tree nuts. Despite the presence of NOW throughout a typical season of almonds and pistachios, the identification of particular VOCs and/or VOC blends, and their potential role as semiochemicals, has not been thoroughly addressed. Recent research in these laboratories has indicated semiochemical behavior from non-pheromonal, plant-derived VOCs and VOC blends. An efficacious attractant for NOW monitoring/control remains elusive despite breakthroughs with the NOW female sex pheromone, and control by other current means has not produced results needed for the California tree nut industry. The VOC emissions of almond and pistachio orchards were collected via a large-scale ambient volatile collection (LSAVC) system and subjected to electroantennographic (EAG) and Y-tube olfactometry bioassay. Synthetic blends mimicking the natural VOC composition of tree nut orchards and potential attractant blends were formulated and evaluated for efficacy as environmentally responsible semiochemicals for NOW.

Technical Abstract: The navel orangeworm (NOW) is a major insect pest of tree nuts and is a vector of Aspergillus flavus – a fungus responsible for aflatoxin contamination of California tree nuts. Despite the presence of NOW throughout a typical season, the identification of particular VOCs, or their potential role as semiochemicals, has not been addressed. Recent research has indicated semiochemical behavior from non-pheromonal, plant-derived VOCs and VOC blends. An efficacious attractant for NOW monitoring/control remains elusive despite breakthroughs with the NOW female sex pheromone. The VOC emissions of almond and pistachio orchards were collected via a large-scale ambient volatile collection system and subjected to electroantennographic (EAG) and Y-tube olfactometry bioassay. Synthetic blends mimicking the natural VOC composition and potential attractant blends were formulated and evaluated for efficacy as environmentally responsible semiochemicals for NOW.