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United States Department of Agriculture

Agricultural Research Service

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Location: Temperate Tree Fruit and Vegetable Research

2013 Annual Report

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. Log 34915. Formerly 5352-22000-017-60T (6/10);5352-22000-019-18T (1/11).

3. Progress Report:
The work summarized in this progress report relates to objective number 6 in the Project Plan for 001-00D: 3. Discover and develop chemical attractants for codling moth, fruit flies, pear psylla, and other insect pests of temperate tree fruits and their natural enemies. The goal of the project was to develop new, more effective management approaches for codling moth, the key pest of apple and pear in the western United States, utilizing the addition of pear ester. Technical objectives were to 1. Develop a hand-applied dispenser loaded with sex pheromone and pear ester that would improve mating disruption and 2. Evaluate the use of a microencapsulated pear ester formulation to both increase the efficacy of a number of larval insecticides with different modes of action, and to improve sex pheromone-based mating disruption of adults. These objectives were met. Several practical applications of the pear ester for management of codling moth were tested and refined over a five year project. Field trials in apple evaluated the addition of a sprayable microencapsulated (MEC) formulation of pear ester to the use of insecticides. The addition of the MEC formulation to insecticides from several mode-of-action classes provided significantly improved control of codling moth. The MEC formulation can allow growers to use reduced rates of insecticides and improve the performance of some of the new classes of more selective materials. Resin dispensers loaded with new sex pheromone and pear ester combined formulations were evaluated each year to produce a series of improvements in formulation efficacy for sexual disruption of codling moth. Dispensers loaded with both pheromone and pear ester significantly reduced the catch of male moths by virgin female-baited traps and reduced the incidence of mating by wild moths. The sum of these experimental results is that the addition of pear ester in combo dispensers reduces female moth mating and subsequently fewer eggs would be laid and the level of fruit injury would be reduced. This result should allow growers to use fewer supplemental insecticide sprays. Second the addition of the microencapsulated pear ester can allow more selective insecticides to provide effective control and a full integration of pear ester-containing dispensers plus a series of pear ester sprays provides the highest level of control and should further reduce the need for supplemental insecticide sprays. These significant results have allowed the manufacturer of pear ester products to move forward to obtain registrations. For example, pear ester products have been registered in South America and Europe and registrations are expected in the USA in late 2013.

4. Accomplishments

Last Modified: 10/18/2017
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