1a. Objectives (from AD-416):
Pear ester has been identified as both a larval and adult attractant for codling moth. Management strategies utilizing pear ester are being developed along several avenues. Both basic and field studies are needed to optimize the rates of pear ester and blends with sex pheromone to achieve effective levels of control. 1. Characterize the emission rate of pear ester over time from field-aged microencapsulated formulations (MEC). 2. Examine larval behavior on host plants treated with various rates and deposition patterns of pear ester MEC. 3. Evaluate the effectiveness of adding pear ester to various insecticides to increase larval mortality including the role of crop and cultivar on activity. 4. Evaluate the interactions of pear ester and sex pheromone combined in various blend ratios on moth orientation responses. 5. Examine the effect of pre-exposure to various rates and blends of pear ester and sex pheromone. 6. Evaluate the effectiveness of various dispensers loaded with blends of pear ester and sex pheromone on male captures by virgin female-baited traps.
1b. Approach (from AD-416):
1) Volatile recapture methodology will be used to quantify the emission rate of pear ester from the MEC formulation aged on apple foliage over a 35 d period. 2) Larval observations will be conducted using several cultivars of apple, pear, and walnut foliage treated with the MEC formulation. 3) Field bioassays will be conducted with a select group of new insecticides registered for codling moth to examine whether the pear ester MEC can enhance insecticidal activity. These studies will focus on the apple cultivar Granny Smith. 4) A piezoelectric sprayer will be used to examine the subtle interactions of pear ester and sex pheromone on adult orientation behaviors. 5) Moth antennal responses following pre-exposure to sex pheromone and pear ester blends will be examined using an EAG and flight tunnel tests will examine moth orientation behavior following exposure. 6) Dispensers loaded with various blends of sex pheromone and pear ester will be evaluated in replicated field plots using virgin female-baited sticky traps. Documents Trust with Trece.
3. Progress Report:
Pear ester is a primary odorant released by ripe fruits of pear, and is an attractant for adults and larvae of codling moth. This discovery has stimulated research by ARS researchers in Wapato, WA, and Albany, CA, to develop a range of management tools for this important pest of apple and walnut. In particular, the use of pear ester in combination with the sex pheromone of codling moth, has allowed the development of improved monitoring lures and mating disruption dispensers. Pear ester has also been microencapsulated to create a sprayable formulation that has been tested with codlemone to disrupt adult sexual communication in apple and walnut. Recent studies have shown that both the catch of male moths in virgin female-baited traps and the mating success of wild moths is lower within plots treated with the combo dispenses than with only sex pheromone. The regular addition of the microencapsulated product to seasonal sprays also significantly reduced levels of fruit injury. Registration of these products is now expected in the U.S. in 2013. The work reported here addresses objective 3 of the parent project plan.