Individual and Additive Effects of Insecticide and Mating Disruption in Integrated Management of Navel Orangeworm in Almonds

Abstract

Damage from Amyelois transitella, a key pest of almonds in California, is managed by destruction of overwintering hosts, timely harvest, and insecticides. Mating disruption has been an increasingly frequent addition to these management tools. Efficacy of mating disruption for control of navel orangeworm damage has been demonstrated in experiments that included control plots not treated with either mating disruption or insecticide. However, the navel orangeworm flies much farther than many orchard pests, so large plots of an expensive crop are required for such research. A large almond orchard was subdivided into replicate blocks of 96 to 224 ha and used to compare harvest damage from navel orangeworm in almonds treated with both mating disruption and insecticide, or with either alone. Regression of navel orangeworm damage in researcher-collected harvest samples from the interior and center of management blocks on damage in huller samples found good correlation for both and supported previous assumptions that huller samples underreport navel orangeworm damage. Blocks treated with both mating disruption and insecticide had lower damage than those treated with either alone in 9 of the 10 years examined. Use of insecticide had a stronger impact than doubling the dispenser rate from 2.5 to 5 per ha, and long-term comparisons of relative navel orangeworm damage to earlier- and later-harvested varieties revealed greater variation than previously demonstrated. These findings are an economically important confirmation of trade-offs in economic management of this critical pest. Additional monitoring tools and research tactics will be necessary to fulfill the potential of mating disruption to reduce insecticide use for navel orangeworm.

From Insect Pheromones to Mating Disruption: Theory and Practice

“…Several novel mating disruption approaches have been developed and/or optimized to manage a broadly diverse number of insect pests. A major focus has been devoted to moth pests, showing carefully conducted mating disruption experiments on grape (Cryptoblabes gnidiella (Millière, 1867) (Lepidoptera: Pyralidae)) [8], plum (Grapholita funebrana Treitschke (Lepidoptera: Tortricidae)) [9], almond (Amyelois transitella (Walker) (Lepidoptera: Pyralidae)) [10], and tomato (Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae)) [11], as well as on polyphagous leafrollers, such as Proeulia auraria (Clarke) (Lepidoptera: Tortricidae) [12]. Concerning mealybugs, further research efforts have been directed to evaluating the potential of P. calceolariae mating disruption in apple and tangerine orchards [13].…”

Diel Periodicity in Males of the Navel Orangeworm (Lepidoptera: Pyralidae) as Revealed by Automated Camera Traps

“…The navel orangeworm Amyelois transitella (Walker) is the primary insect pest of California’s economically important tree nut industry ( Wilson et al 2020 ). Mating disruption is an established management technique for this pest ( Higbee et al 2017 , Burks and Thomson 2019 , 2020 ; Haviland et al 2021 , Higbee and Burks 2021 ). Aerosol technology is used in three of the four commercial formulations for which efficacy has been demonstrated ( Haviland et al 2021 ).…”