Efficacy of a novel baited trap at capturing gravid navel orangeworm (Amyelois transitella)

Sex ratio and gravidity of captured navel orangeworms (NOW; Amyelois transitella; Lepidoptera, Pyralidae) were determined from moths trapped in a novel bait and standard wing trap deployed in California almond orchards. Studies were performed over a 70 day period from May to September of 2010 in Colusa and Tulare counties. The sex and gravidity of captured NOW were determined via presence or absence of ovipositor and spermatophore. In Colusa and Tulare counties a total of 111 and 106 moths were captured, respectively. Of the total moths trapped, 100% were determined to be female and 96% and 70% were gravid in Colusa and Tulare counties, respectively. Comparison of total moths per trap revealed a higher density of NOW at the Tulare site than the Colusa county field site. Results from this study illustrate the potential use of this novel baited trap as an effective monitoring tool for NOW in almonds. More effective monitoring tools could theoretically assess NOW populations in almond orchards with greater accuracy and provide information essential to optimize timing of insecticide applications for NOW.