ARS | Publication request: Seasonal Abundance of Navel Orangeworm (Lepidoptera: Pyralidae) in Figs and Effect of Peripheral Aerosol Dispensers on Sexual Communication

Submitted to: Journal Of Insect Science
Publication Acceptance Date: April 12, 2004
Publication Date: August 25, 2004
Citation: Burks, C.S., Brandl, D.G. 2004. Seasonal Abundance Of Navel Orangeworm (Lepidoptera: Pyralidae) In Figs And Effect Of Peripheral Aerosol Dispensers On Sexual Communication. Journal Of Insect Science.

Interpretive Summary: The navel orangeworm is an important pest of California crops including figs, almonds, pistachios, and walnuts. We examined the ability of a network of 80 timed release aerosol dispensers, placed around 16-ha treatment plots, to completely prevent males from finding females within the treatment plots over two growing seasons. Data from untreated comparison plots showed that navel orangeworm abundance in figs is high during the first and third flights, but low during the second. Since current-crop Calimyrna figs are not susceptible to navel orangeworm infestation until late in the second flight, these data suggest that delaying the beginning of mating disruption treatments from the first to the second flight might be done without loss of efficacy. While data gathered in this study indicates that the navel orangeworm is often not the most important insect pest of figs, the patterns of moth seasonal abundance and fruit susceptibility in almonds are similar to those in figs.

Technical Abstract: We used flight traps baited with unmated female navel orangeworm Amyelois transitella (Walker) to examine, over two growing seasons, seasonal changes in the abundance of males in fig orchards and the impact of release of the pheromone component (Z,Z)-11,13-hexadecadienal from peripherally-located timed-release dispensers on the ability of male to find unmated females within 16-ha treatment plots. Material was placed out and mating disruption was commenced at the beginning of April in the first year, and at the beginning of July the second year. This technique effectively prevented males from finding females in female-baited traps placed throughout the plot. Navel orangeworm abundance was high in figs during the first and third generation, but lower in June and July during the second generation. Since the current year crop of Calimyrna figs is not susceptible to attack by navel orangeworm until mid-to-late July, these findings suggest that materials cost can be reduced by beginning treatment later. Implications for insect pest management in figs and other California crops are discussed.