Mating disruption of the navel orangeworm (Lepidoptera: Pyralidae) using widely spaced, aerosol dispensers: is the pheromone blend the most efficacious disruptant?

Authors: HIGBEE, BRADLEY - Trece, Inc; Burks, Charles - Chuck; CARDE, RING - University Of California

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/6/2017
Publication Date: 6/20/2017
Citation: Higbee, B.S., Burks, C.S., Carde, R.T. 2017. Mating disruption of the navel orangeworm (Lepidoptera: Pyralidae) using widely spaced, aerosol dispensers: is the pheromone blend the most efficacious disruptant? Journal of Economic Entomology. doi:10.1093/jee/tox185.

Interpretive Summary: The navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is a key pest of almonds and pistachios and is sometimes controlled using mating disruption as part of a program of integrated management. This study compared the current non-attractive mating disruption formulation with two aerosol formulations containing additional compounds that are attractive in laboratory and field trials. In pistachio, where abundance was higher, the more complete blends resulted in higher suppression of males captured in female-baited traps, and of mating in sentinel female assays. In almond all three formulations provided over 99% suppression of males captured and females mated, and all resulted in lower crop damage compared to the non-mating disruption control. These findings suggest that it may be possible to make mating disruption more cost-effective by using attractive aerosol formulations to reduce the number of dispensers per hectare required.

Technical Abstract: The navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is a key pest of almonds and pistachios and is sometimes controlled using mating disruption as part of a program of integrated management. The formulation used has a single, non-attractive compound [(Z,Z)-11-13-hexadecadienal] as the active ingredient that is emitted from timed aerosol dispensers. This study compared this non-attractive, single-compound formulation with two aerosol formulations also containing two additional compounds [(Z,Z)-11,13-hexadecadien-1-ol and (Z,Z,Z,Z,Z)-3,6,9,12,15-tricosapentaene] that are found in the pheromone glands, and that in combination with the aldehyde are attractive in wind-tunnel and field-attraction trials. An experiment in pistachios found 97 to 99% suppression of males in female-baited traps and 82-93% suppression of mating in sentinel females. Both assays revealed a trend to greater suppression by the more complete pheromone formulations. In almonds, where the abundance of navel orangeworm was lower, all three formulations suppressed males in traps and mating in sentinel females by >99%. Each of the formulations significantly reduced damage to Nonpareil almonds. In almonds there were no significant differences among the formulations in disruption of sexual communication or in damage. These findings suggest that it may be possible to make mating disruption more cost-effective and/or to achieve higher levels of mating disruption by using attractive aerosol formulations to reduce the number of dispenser per ha. Such a formulation, however, would be more expensive to register in the U.S. than pheromones meeting the definition of straight-chain, lepidopteran pheromone, including the currently used aldehyde-only formulation.