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2022 Pear Pest Scouting

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Authors: Robert Orpet, Chris McCullough, Molly Sayles and Louie Nottingham; WSU Entomology. March 14, 2022

The Nottingham lab at WSU-TFREC is monitoring pear pests at seven commercial locations in the Wenatchee Valley in addition to the WSU research center orchard (‘Sunrise’) near Rock Island (Figure 1). At each location, one block follows our phenology-based IPM guidelines and another block follows standard conventional management. We are also monitoring organically managed blocks at three of the locations. All blocks contain mostly Anjou and Bartlett trees planted >50 years ago, except for Rock Island, which was planted in 2007.

A summary of pear psylla adult, egg, and nymphs across sites is in Figure 2 (Summer) and Figures 3-4 (Spring), and data per site in are in Tables 1–6.

How we Sample

We sample pear psylla adults (Table 1) and natural enemies (Table 4) with beat tray taps. In spring, we collect buds to monitor psylla eggs and nymphs.  In summer through fall, we collect leaves to monitor psylla eggs (Table 2) and nymphs (Table 3), mites (Table 5), and earwigs (Table 6).


 

A map of the Wenatchee valley with dots for the seven paired sampling sites from Rock Island to Leavenworth.

Figure 1. Areas of paired pear orchards for pest monitoring in commercial orchards (panel A) and the WSU SRO pear blocks (panel B). AgWeatherNet (AWN) temperature sensor locations are indicated with blue points, city landmarks with red.

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For the Week of September 19

 

Announcement:

We will be hosting a pear psylla field day on September 21st from 10:00 a.m. – 12:00 p.m. The goal of the field day is to discuss the outcomes of the first year of the phenology program and compare conventional and phenology-managed orchards. The event will count for 2 pesticide credits.

Visit EventBrite to register (it’s free!) and get all of the details.

 

Pear psylla degree-days:

  • Current PDD (9/16): 4340 Wenatchee, 4014 Cashmere, 3560 Peshastin
  • Projected PDD (9/23): 4476 Wenatchee, 4150 Cashmere, 3680 Peshastin

Current guidelines (3500 PDD):

Honeydew washing is the best tactic around harvest. If desired, use a short-PHI organic product following a wash, but be careful not to mark fruit. Visit location-specific links below for more management guidelines:

How is the phenology-based program doing?
This was a tough year for pear psylla throughout the valley, but the phenology-based IPM program worked as expected relative to conventional orchards. In 4 out of 8 phenology program sites, biocontrol has resulted in less pear psylla at harvest time. In the other 4 phenology sites, where biocontrol was more limited, outcomes currently similar to the conventional paired sites. Overall, the phenology-based program was similar or better to conventional. We will be collecting spray records later to assess costs. In future years on the project, we will be able to see if biocontrol improves at sites where it was limited this year and stays consistent at others.

Site specific graphs of psylla abundance are posted on the project webpage if you would like to see the data for your orchards.

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Summer Sampling (May 30 through present)

Figure 2. Summer (starting 30 May) summary of pear psylla adults, eggs, and nymphs across 8 conventional, 8 phenology-based IPM, and 3 organic pear orchards. Psylla art by Toriani Kent.


 

Summer Sampling (May 30 through present)

Psylla Adults Per Tray Tap (Summer)

Table 1. Pear psylla adults per tray tap paired orchards (C = conventional, P = Phenology-based IPM, O = organic). Dates represent the week of the sample. Cells with “–” indicate no sample due to site inaccessibility or re-entry intervals.

PP adults/tray 8/15 8/22 8/29 9/5 9/12
Rock Island 1 C 0.6 1.0 0.6 1.6 2.9
P 0.6 0.2 0.2 0.04 0.12
Monitor 2 C 16.2 7.3 9.7 7.3 10.6
P 6.2 3.4 2.4 2.1 1.4
Cashmere 3 C 7.7 4.6 2.4 4.8 7.7
P 4.9 2.4 1.9 0.4 0.5
O 7.4 1.8 3 0.8 0.2
Dryden 4 C 2.1 0.9 2.3 6.7 6.3
P 3.3 3.8 3.9 5.8 4.3
Dryden 5 C 4.7 6.0 14 22 24.7
P 4.0 2.2 3.2 4.3 5.9
O 5.3 3.9 3.7 1.5 0.9
Peshastin 6 C 6.2 6.4 0.7 2.6 1.4
P 7.0 4.6 2 1.9 1.1
O 10.6 5.8 1.9 1.7 0.9
Highway 97 7 C 5.6 2.6 2.4 7.6 *
P 0.8 0.5 0.4 0.2 *
Leavenworth 8 C 9.7 4.2 2.6 7.7 7.5
P 23.4 9.4 8.04 11.7 8.6

*air quality prevented scouting

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Psylla Eggs per Leaf (Summer)

Table 2. Pear psylla eggs per leaf paired orchards (C = conventional, P = phenology-based IPM, O = organic). Dates represent the week of the sample. Cells with “–” indicate no sample due to site inaccessibility or re-entry intervals.

PP eggs/leaf 8/15 8/22 8/29 9/5 9/12
Rock Island 1 C 0.2 0.02 0.3 0.06 0.2
P 0.04 0.2 0.08 0 0.04
Monitor 2 C 2.8 0.8 1.4 3.9 1.1
P 0.4 0.4 0.7 0.4 0.3
Cashmere 3 C 0.8 0.4 0.2 0.6 0.3
P 0.1 0.04 0.8 0.02 0.06
O 0.4 0.1 0.6 0.2 0.04
Dryden 4 C 0.2 0.06 1.1 1.4 0.5
P 1.0 0.8 0.7 0.8 0.6
Dryden 5 C 0.5 0.4 0.2 1 0.7
P 0.2 0.3 0.06 1.3 0.5
O 0.2 0.3 0.1 0.2 0.1
Peshastin 6 C 0.4 0.3 0.3 0.2 0.6
P 1.6 0.6 0.1 0 0.2
O 0.8 1.5 0.2 0.04 0.6
Highway 97 7 C 0.3 1.8 0.1 0.08 *
P 0.04 0.1 0.06 0.2 *
Leavenworth 8 C 0.6 0.2 0.02 0.7 0.4
P 0.8 0.4 0.02 0.5 3.3

*air quality prevented scouting

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Psylla Nymphs per Leaf (Summer)


 

Natural Enemies (Summer)

Table 4. Natural enemies (Deraeocoris nymphs and adults, Trechnites wasps, and Camplylomma nymphs and adults) per 25 trays at paired orchards (C = conventional, P = phenology-based IPM, O = organic). Dates represent the week of the sample. Cells with “–” indicate no sample due to site inaccessibility or re-entry intervals.

NEs/tray 8/15 8/22 8/29 9/5 9/12
Rock Island 1 C 0.04 0.1 0.04 0.08 0.8
P 0.2 0.1 0.2 0.2 0.9
Monitor 2 C 0.2 0.2 0.08 0.2 0.4
P 1.2 2.3 1.4 0.6 0.7
Cashmere 3 C 0.2 0.04 0 0 0
P 8.5 2.0 4.08 0.4 0.8
O 4.2 0.8 0.6 0.6 0.4
Dryden 4 C 0 0 0 0 0
P 0.3 0.04 0.08 0 0
Dryden 5 C 0.04 0.1 0.04 0.1 0.3
P 0 0 0.04 0.08 0.04
O 0.3 0.3 0.6 0.4 0.4
Peshastin 6 C 0 0.2 0 0.2 0
P 0.5 0.6 0.7 0.9 1.2
O 2.3 2.7 0.8 1.4 1.08
Highway 97 7 C 0.2 0.1 0 0.08 *
P 1.0 1.1 1.2 0.6 *
Leavenworth 8 C 0.04 0.1 0.08 0 0.08
P 0.7 2.4 1.3 1.04 0.8

*air quality prevented scouting

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Mites (Summer)

Table 5. Total Two-spotted spider mites per leaf at paired orchards (C = conventional, P = phenology-based IPM, O = organic). Dates represent the week of the sample. Cells with “–” indicate no sample due to site inaccessibility or re-entry intervals.

TSM/leaf 8/15 8/22 8/29 9/5 9/12
Rock Island 1 C 0 0.02 0 0 0
P 0 0 0 0.04 0.02
Monitor 2 C 0.02 0 0.4 0.02 0.2
P 0.02 0 0.06 0.02 0
Cashmere 3 C 0.06 0 0 0 0.02
P 0.06 0.06 1 0.2 0.4
O 0.8 0.4 1.7 0.4 0.7
Dryden 4 C 0.02 0.2 0.4 0.4 1.08
P 0.6 3.1 4.9 1.02 2.8
Dryden 5 C 0 0 0.1 0.8 3.6
P 0 0.04 0.02 0.3 0.5
O 2.2 35 3.3 2.2 0.7
Peshastin 6 C 0.02 0.7 0 0.02 0.1
P 0 0.1 0 0 0.02
O 0 0.4 0.02 0.1 1.4
Highway 97 7 C 0.04 0.04 0.06 0.02 *
P 0 0 0 0 *
Leavenworth 8 C 2.7 2.2 0.7 3.1 6.8
P 0.1 0 0 0.06 0.1

*air quality prevented scouting

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Earwigs (Summer)

Table 6. Total Earwigs per cardboard at paired orchards (C = conventional, P = phenology-based IPM, O = organic). Dates represent the week of the sample. Cells with “–” indicate no sample due to site inaccessibility or re-entry intervals.

Earwigs 7/4 8/5 9/5
Rock Island 1 C 1.0 1.75 1.8
P 36.8 7.8 24
Monitor 2 C 0 0 0
P 0 0 0
Cashmere 3 C 0 0 0
P 0.2 1.6 2.8
O 0.2 0 1.0
Dryden 4 C 0 0 0
P 0 0 0
Dryden 5 C 0 0 0
P 0 0 0.2
O 2.6 4.4 3.6
Peshastin 6 C 0 0 *
P 0 0 *
O 0 0 *
Highway 97 7 C 0 0 0
P 0 0 0
Leavenworth 8 C 0.2 0.8 0.3
P 0 0.2 0

*site will be counted next week

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Links
All data from the project are publicly stored here: http://treefruit.wsu.edu/crop-protection/pear-ipm/2022-pear-pest-scouting/
Site-by-site summary graphs are here: http://treefruit.wsu.edu/crop-protection/pear-ipm/2022-pear-pest-scouting/#links
There is a sign-up link for these weekly updates you can feel free to share: http://eepurl.com/h03YQL

Spring Sampling Summary (March through May)

Figure 3. Summary of pear psylla adults per tray, eggs per flower cluster, and nymphs per flower cluster. Means among sites (N = 8 Conventional, 8 Phenology, and 3 Organic orchards) per sample week are represented by points with standard error bars. Flower clusters inspected consisted of dormant flower buds, green tissues after budbreak, or three leaves and flower pedicels per cluster once leaves were expanded.
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Figure 4. Spring 2022 scouting summary, conventional vs phenology.

 


 

Contact Information

Robert Orpet

Dr. Robert Orpet
Postdoctoral Research Associate
WSU Tree Fruit Research & Extension Center
1100 N Western Ave., Wenatchee, WA 98801
robert.orpet@wsu.edu

Chris McCullough

Dr. Chris McCullough
Postdoctoral Research Associate
WSU Tree Fruit Research & Extension Center
1100 N Western Ave., Wenatchee, WA 98801
christopher.t.mccul@wsu.edu

Dr. Louis Nottingham
Assistant Professor
WSU Tree Fruit Research & Extension Center
1100 N Western Ave., Wenatchee, WA 98801
louis.nottingham@wsu.edu
540-798-2044 (cell)

Molly Sayles
PhD student
WSU Tree Fruit Research & Extension Center
1100 N Western Ave., Wenatchee, WA 98801
molly.sayles@wsu.edu

This Project was Funded by:

 

 

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