PIPE Soybean Aphid Workshop Report

Abstract

The soybean aphid PIPE is entering its second year. Experience gained during the first year of operation was used to guide changes to the soybean aphid sampling protocol for year two. Participants decided to reduce the number of observation entry form types to two: single observation sites and repeated observation sites. The "rain sampled since last time", "rain amount", and "drought stress" fields were eliminated from the repeated observation site form. The aphid map display categories were reviewed and one was added at the lower end of the scale to provide greater resolution: a) 0 b) 1-5 c) 6-39 d) 40-149 e) 150-249 f) 250-499 and g) 500 and above. An automated procedure for transferring soybean aphid observations from the restricted access to public website will be available in 2007. The Treatment Statement Threshold was reviewed and accepted for 2007. It was decided to include the aphid suction trap network data on the restricted website in a manner similar to the spore trap network data that is part of the soybean rust interface. The 2007 PDA observation entry software for soybean aphid was presented to the group.

Workshop agenda

1. Updating the existing protocol for 2007
2. Revisions to data entry forms related to soybean aphid monitoring.
3. Discussion of how best to streamline the process for transferring observations from the restricted website to the public website.
4. Integration of the soybean aphid suction trap network into the PIPE.
5. Demonstration of PDA software for soybean aphid observation entry.

Participants

Eighteen researchers and PIPE administrators attended the PIPE workshop. Individuals who participation in the discussions included: Amanda Bachmann (Pennsylvania), Wayne Bailey (Missouri), Tracey Baute (Ontario), Eileen Cullen (Wisconsin), Chris DiFonzo (Michigan), Marty Draper (USDA CSREES), Julie Golod (Pennsylvania), Ron Hammond (Ohio), Ames Herbert (Virginia), Scott Isard (Pennsylvania), Janet Knodel (North Dakota), Rick Meyer (USDA CSREES), Matt O'Neal (Iowa), Dave Ragsdale (Minnesota), John Reese (Kansas), Michele Roy (Quebec), Kelly Tilmon (South Dakota), and David Voegtlin (Illinois).

Introduction

Scott Isard welcomed participants and thanked them for coming early to the S1010 meeting to participate in the PIPE workshop. He stressed that the primary goal of the meeting was to finalize the sampling protocol so that PIPE programmers could start working on the observation entry software for 2007. He thanked Ames and Eileen for all their work on the protocol over the past few weeks. Participants introduced themselves indicating their names and affiliations.

Soybean aphid sampling protocol

Julie Golod led a discussion of the proposed soybean aphid sampling protocol for 2007. The hand out that formed the basis of the discussion was divided into the following five sections.
Background Information

• Soybean aphid monitoring is more important later in the season. Weekly scouting for SBA will be necessary when 1) SBA is reported in the region, or 2) soybean plants are in the late vegetative (pre-reproductive) to early reproductive (i.e. flowering) growth stage. Soybean aphid may reach threshold in some instances prior to the reproductive growth stage, but current research data suggests that treatment during this stage is not likely to result in an economic return.
• In most cases, weekly scouting will be necessary for no more than 8-10 weeks. Individual state entomology extension specialists will determine when weekly scouting is warranted.

Field Types and Naming

• Sentinel Sites, Grower Fields, or Experiment Station Fields¹ can be used for soybean aphid monitoring, as long as the scouting protocol is followed. The decision on the site selection is left up to the discretion of each individual state extension entomologist.
• The extension specialist in states funded for SBA monitoring will select field site locations for weekly scouting and report those into the USDA PIPE database. However, reports from random or intermittent ('mobile') fields may also be included in the database. To provide data into the PIPE database each location needs to have a unique name. A location naming convention has been proposed to assure uniformity across states, please see attached. Also remember to record GPS coordinate data (in decimal degrees) along with county and host information².

Recommended Sampling Procedure

• When scouting for SBA, select 20 plants at random, each from a different location (not consecutive down the row) so that the 20 plant-sample is representative of the entire variety/cultivar. Identify the average plant growth stage.
• Examine the entire plant beginning with the growing point (newest trifoliate) for soybean aphids. If plants are in vegetative growth (no pods or flowers) generally only the growing point needs to be examined. As flowering and pod set occur, examine the entire plant, including pods. Spend no more than 30 sec to examine an individual plant³.
• Count aphids when there are 250 or fewer per plant. Estimate numbers when populations are above 250 per plant. Categorize numbers as follows: 250-499 or 500 or above. (FYI: within-field aphid numbers will be mapped on the PIPE site in the following categories a) 0 b) 1-5 c) 1-39 d) 40-149 e) 150-249 f) 250-499 and g) 500 and above.)
• Please indicate the number of plants examined when the number is other than 20.

Other Pest Observations/Optional Notes

• Apterous (wingless) aphids are assumed to be present. Note whether or not a late (winged) aphids were also observed. If only winged aphids are present (very rare, but possible), indicate this information in the space for optional notes. Notes could also be used to mention if any predators or parasitized aphids (mummies) are present or other general relevant observations
• It is recommended that notes of presence and/or infestation levels of other economically important pests of soybean and other legumes such as common bean also be mentioned by observers. Bean leaf beetle is an important pest of soybean and Mexican bean beetle and leafhoppers are important pests of common bean; and information regarding these pests could be beneficial and utilized by the local state extension specialist in their commentary to growers.

Unusual Aphids/Lab Diagnosis

• Unusual aphids should be submitted to your local National Plant Diagnostic Network (NPDN)lab for specimen preparation and initial screening. Please see the NPDN Soybean Standard Operating Procedure (SOP) for more information. Dr. David Voegtlin, Illinois Natural History Survey, will serve as an expert taxonomic confirmation specialist for soybean aphid or unusual aphids detected through this program. If any unusual or suspect exotic aphids are detected, Dr. Voegtlin will appropriately communicate with 1) the NPDN and 2) Dr. Gary Miller at the USDA Systematic Entomology Laboratory in Beltsville, MD in order to ensure that proper procedures of exotic pest notification are followed.

A lively discussion followed. There were a number of objections to location types that were used last year. The "commercial" designation was deemed inappropriate because the sites were not always in commercial fields and in reality a "commercial" site was simply a site that was sampled once during the season. Some participants also objected to the terminology "Ad-Hoc". The group decided to reduce the number of observation entry forms to two types: single observation sites and repeated observation sites. The Ad-Hoc and Sentinel categories from 2006 were merged into the repeated observation site category for 2007. However, within those two broad categories users will be able to indicate if the site is located in a production field, research field or a sentinel plot. Other categories may be added to this list over the next few weeks. In 2006, data from each of 20 plants observed was entered into PIPE. In 2007, only the average will be recorded. Because the protocol for sampling aphids in sentinel plots has been simplified to resemble the Ad-Hoc protocol, this merger into a repeated observation site form was deemed practical.

The group decided that the phrase "Spend no more than 30 sec to examine an individual plant" should be eliminated from the recommended sampling procedure. They added a category at the lower end of the scale to increase the resolution of the aphid map display: 0, 1-5, 6-39, 40-149, 150-249, 250-499, >500. They also agreed to eliminate the "rain sampled since last time", "rain amount", and "drought stress" fields from the observations forms. There was a discussion of whether or not there should be an incidence field on the forms to record the proportion of the plants sampled on which aphids were found. The group decided to include incidence (percent of plants sampled) as a non-required field on the data entry forms. During the S1010 general meeting that followed, the issue of estimating or counting aphids when numbers per plant were large arose. Participants agreed that is important to be able to distinguish between actual counts and estimates of aphid numbers. A required field will be added to the observation menu that indicates if the average of soybean aphid per plant are derived from an estimate.

Data transfer

Golod presented a number of options for making the process of transferring the observations from the restricted access website observation map to the public observation map. The group at the workshop was in favor of making the transfer process automatic. However, when this issue was discussed at the S1010 meeting the following day, some state specialists wanted to maintain the manual transfer process because it gave them more control over what observations were released to the public and when. It was decided that specialists will have the option to designate that data be transferred automatically from the restricted access to the public web site, otherwise data transfer will follow the 2006 manual process. Automatic transfer will occur daily at the 1700 Pacific time. For the automated process, additional functionality will be added to remove "old" data from the public site. A single observation type data point will be removed two weeks after the observation date, if it has not been updated. If no new observations are reported for a repeated observation points for two weeks, the color of the symbol on the map will change to white (empty) indicating a "no data available" status; however, the symbol will remain on the public map. A new tool will be developed to allow specialists to remove individual points from the public display.

Plot naming convention.

A naming convention proposed by Golod for sampling plots was reviewed and accepted by participants. Use of the naming convention is recommended but not mandatory in 2007. The convention will be similar to that presented below. However, because the group made considerable changes in the location type categories at the workshop, the convention below will be revised to account for those changes. The location names will be case insensitive.

YYSTNAMELTPNNCC

Where:
YY = year (the last two numbers) ex. 2007 = 07
ST = state postal code (2 letter abbrev) ex. Florida = FL
NAME = county (preferred), but nearest city or other convenient name is also acceptable. Maximum number of characters is 8 and no spaces. Example: Hernando=hernando or hern
LTP = location type (3 letter abbreviation). Example: Sentinel=snt
NN = counter to distinguish site of the same location type within a county from others (sequence starts over at 1 for new county and new location type). Maximum number of characters is 2.
CC = an alpha counter to indicate when more than one of the following is present at a site - cultivar, hosts, or planting date (sequence starts at "a"), or use the name of the cultivar/host. Maximum number of characters is 8 and no spaces are permitted. This counter/cultivar should be ignored if the site has only one host/cultivar.

Abbreviation for location type
Sentinel in season = SNT
Sentinel over-wintering = SOW
Commercial/Production Locations = CMR
Kudzu/wild legumes = KDZ
Volunteer Bean = VLN
Unknown/Other = UNK

Example 1: A site with several cultivars: 07FLHERNANDOSNT1A
Example 2: A site with one cultivar: 07FLHERNANDOSNT1

Treatment threshold statement

Golod asked the participants to review the current threshold statement (below).
CURRENT THRESHOLD STATEMENT

• Thresholds have been reached if there are 250 or more aphids per plant on approximately 80% of the field and aphid populations are increasing and the soybean crop is within the reproductive stages (i.e. flowering) of R1 (first bloom) up to and including R5 (beginning seed). This threshold incorporates an approximately 7-day lead-time between scouting and treatment to make spray arrangements or handle weather delays. Sequential scouting in the same field is necessary in order to determine if populations are increasing.
• Though uncommon, an insecticide application may be necessary if soybean aphids reach thresholds (250 aphids per plant with increasing populations on 80% of the plants in the field) during the vegetative (V) stages of soybeans. Consult with your state/provincial extension specialist for further advice in this situation. A second application may be necessary later in the season should soybean aphids reach thresholds again during the R1-R5 stages of soybeans.
• Once in the R6 growth stage, a higher number of aphids per plant is required for economic return but no threshold is available at this time. If treatment options are considered, ensure pre-harvest intervals of the insecticidal product chosen are met prior to application.
• Beyond the R6 stage of soybeans, there is no economic return on insecticidal applications for soybean aphid control.

A discussion followed over the statement "Once in the R6 growth stage, a higher number of aphids per plant is required for economic return but no threshold is available at this time" The use of the word "is" was questioned as being too strong. In the end, the group decided not to alter the statement in the current document.

Soybean aphid suction data display.

The group agreed that the aphid suction trap network data should be displayed on the restricted website in a manner similar to the spore trap network data that is part of the soybean rust interface. The aphid suction trap display categories will be based on the range of that data, and will differ from the observation data categories.

Legume virus project.

The group reviewed a set of slides from Sue Tolin about the Legume virus PIPE for 2007. The National Coordinators for the project are Gail Wisler and Kitty Cardwell. Marie Langham (South Dakota) is chair of the group. Howard Schwartz (Colorado) and Sue Tolin (Virginia) are leading the sampling and diagnostic components respectively while Don Hershman (Kentucky) and Julie Golod (Penn State) are organizing the reporting and databasing processes.

PDA Software

Golod quickly ran through a slide presentation showing the steps involved in using the 2007 PDA software to record and upload observations from single and repeated observation sites. The informal presentation generated questions regarding the requirement for a PDA with a windows operating system. Isard thanks the group for their valuable input.

The workshop was adjourned at about 5:15 p.m. He (PIPE) offered dinner at a local restaurant to all participants