Location: Temperate Tree Fruit and Vegetable Research
Project Number: 2092-22430-003-021-A
Project Type: Cooperative Agreement
Start Date: Oct 1, 2020
End Date: Sep 30, 2023
Objective:
1. Develop a mass trapping protocol for earwigs to support releases in pome fruit by removing them from stone fruit orchards where they are pests.
a. Determine which trap type catches the largest number of earwigs in stone fruit orchards
b. Measure success of earwig mass trapping in stone fruit orchards
2. Examine potential of earwig augmentation in pome fruit.
a. Determine if earwigs cause damage to pears or to ‘Honeycrisp’ or ‘Gala’ apples
b. Determine optimal release rates and timing to establish augmented earwigs
c. Examine the efficacy of adding shelters to increase abundance of existing earwig populations
d. Test potential of using drones to release earwigs
3. Screen non-target effects of pesticides on earwigs.
a. Determine acute short-term toxicity of organic and conventional tree fruit pesticides to earwigs
b. Examine sublethal effects of pesticides on earwig motor coordination and predation
4. Improve stakeholder knowledge on earwig IPM.
a. Summarize research findings at grower meetings
b. Conduct field days on collaborating grower farms to demonstrate earwig monitoring and effects on pest populations
c. Create widely available extension documents describing earwig biology, monitoring, and augmentation
d. Create an online video and photo library to convey project results and demonstrate earwig trapping and augmentation
e. Measure changes in grower knowledge with surveys throughout the project
Approach:
1a. To determine the most effective trap to maximize earwig catch, we will deploy four earwig trap types in stone fruit orchards in Wenatchee (commercial nectarine), Moxee (research cherry), and Medford (research cherry). We will examine standard tubes and bands, and soda shelters, which are strips of cardboard rolled in a cylinder and secured inside a large soda bottle with the base removed.
1b. Plots of the highest-catching trap type in Obj. 1a will be compared to a no-removal for earwig abundance and damage.
2a. We will conduct no-choice tests for each fruit type. A ‘Honeycrisp’ fruit cluster or three ‘Bartlett’ fruits will be placed in a cage with ten earwigs (10 cages/replicates per fruit) and a water source. Damage will be recorded twice weekly for four weeks.
2b. For apple, the study will be a crossed design of release rates (10 or 100 earwigs/tree) and timings (June or September), with a no-release control. For pear, we will monitor 7 orchard blocks, with 200 earwigs released on a focal tree in each of six plots within each orchard and compare earwig numbers and pest damage to an additional six plots where earwigs are not released.
2c. In commercial apple (Yakima) and pear (Wenatchee) orchards, soda shelter and no-shelter treatments will be evaluated. Shelters will be placed in June and left in the orchard for two months. Shelters will then be removed for a week (releasing any earwigs), followed by earwig sampling in shelter-added versus control plots for two weeks (once weekly). This will allow us to determine if shelters increase earwig populations.
2d. The purpose of this study is to determine if drone releases of earwigs can be substituted for more time-consuming hand releases by checking earwig establishment post-release. We will compare hand release, drone release, and no release treatments in commercial orchards in Parkdale (pears), Wenatchee (pears), and Yakima (apples). We will release ~200 immuno- and fluorescent-marked earwigs/plot in June 2021 and monitor earwig establishment.
3a. Insecticides/miticides, particle films, herbicides, and a water control will be tested to determine if they cause earwig mortality.
3b. Earwigs will be monitored for decreases in locomotion and predation capability if they survive the mortality assays.
4. Information learned from the project will be presented to stakeholders in the form of scientific articles, a website, extension publications, and on-farm grower field days.
