1a. Objectives (from AD-416)
To monitor natural enemy densities of key moth pests in orchards with and without navel orangeworm mating disruption. Initial studies will focus on the moth pests and natural enemies found in almonds, pistachios, and walnuts, which have the greatest potential for change.
1b. Approach (from AD-416)
Navel orangeworm (NOW): Goal is to compare changes in NOW parasitism levels at three critical periods: (i) after the first NOW summer generation (ii) at harvest time, and (iii) during the overwintering period. At each site, a minimum of 1000 nuts will be collected and dissected for NOW or parasitoids. Peach Twig Borer: The peach twig borer adult flight periods will be monitored using pheromone traps. PTB larval infestation will be monitored at three critical periods: (i) during spring (ii) at harvest time, and (iii) during the overwintering period. Nuts will be collected to determine levels of infestation Oriental fruit moth: The oriental fruit moth (OFM) adult flight periods will be monitored using pheromone traps. OFM larvae will be collected to determine infestation levels and parasitism in a similar manner as described for PTB. Leafrollers: Populations of leafrollers including obliquebanded leafroller (OBLR), fruittree leafroller (FTLR), the filbertworm (FW), and omnivorous leafroller (OLR), will be assessed over the next 3 years, in the NOW mating disruption program. The species of moth and their infestation levels will be determined for the three regional areas of the NOW mating program. A color brochure will be developed that provides a picture key, along with some field taxonomy guides, to identify the different secondary moth larvae. A brief description of their biology and control will also be provided.
3. Progress Report
This research contributes to objective 1 of the in-house project. The goal of this project is to evaluate the impact of mating disruption to control navel orangeworm on populations of beneficial insects and secondary almond pests. Two ARS entomologists and one entomologist from UC Berkeley, based in Parlier, CA are collaborating on this project in the San Joaquin Valley so that the efficacy of mating disruption employing aerosol puffers can be demonstrated. Baseline NOW and beneficial insect population data were collected from the 2008 crop season, and changes in these levels will be compared to mating disruption in 2009 and 2010. Two species of parasitoids that attack navel orangeworm were identified and the relationship between reduced insecticide use and their prevalence will be determined. Cooperator activity was monitored by reports at a stakeholder meeting in August, presentations made to the Almond Board of California, telephone conversations and e-mail.