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2023 Update: Aphid addition and exclusion

The aphid addition and exclusion experiment was started in 2011 by Katherine Muller. The original experiment included 100 plants selected from exPt01 which were each assigned to have aphids either added or excluded through multiple years. The intention is to assess the impact of the specialist herbivore Aphis echinaceae on Echinacea fitness.

Last summer (2022), team members Emma Reineke and Kennedy Porter were in charge of the experiment and did not find any aphids in exPt01, so they introduced a new population of Aphid echinaeceae into ExPt1. Learn more in the 2022 summer aphid update. During summer 2023, we did not do any fieldwork for this experiment and we didn’t see any aphids while measuring exPt01.

Aphids spotted by Abby VanKempen in 2016
  • Start year: 2011
  • Location: exPt01
  • Overlaps with: Phenology and fitness in P1
  • Data collected: 
    • none in 2023
  • Samples collected: NA
  • Products:
    • Andy Hoyt’s poster presented at the Fall 2018 Research Symposium at Carleton College
    • 2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
    • 2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads

You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.

2023 Update: Common garden experiments

Every year since 1996, Team Echinacea members record flowering phenology, taking measuring data and harvest heads of thousands of Echinacea angustifolia plants in common garden experiments. These experimental plots are prairie restorations and abandoned agriculture fields that are managed as grassland habitat. Some plots have multiple ongoing experiments within. Currently, the Echinacea Project currently has 10 established experimental plots.

This project status report will contain updates on experimental plots 1, 2, 4, 5 and 8, as well as management updates for all plots. Specific reports for the remaining experimental plots can be found on separate posts including Amy Dykstra’s plot (exPt03), the hybrid plots (exPt06, exPt07, exPt09), and the West Central Area common garden (exPt10).

exPt01: Experimental plot 1 was first planted in 1996 (cleverly termed the 1996 cohort), and has been planted with nine other experiments in subsequent years, with the most recent planting being Amy Waananen’s inter-remnant crosses. It is the largest of the experimental plots, with over 10,000 planted positions; experiments in the plot include testing fitness differences between remnants (1996, 1997, 1999), quantifying effects of inbreeding (inb1inb2), and assessing quantitative genetic variation (qgen1). There are also a number of smaller experiments in it, including fitness of Hesperostipa sparteaaphid addition and exclusion, and pollen addition and exclusion (the last experiment was continued the summer of 2023 and will have separate update posts). In 2023, we visited 3,699 of the 10,992 positions planted and found 3,118 alive. 560 plants were classified as “flowering” in exPt01 this year. This is a little less than half of the plants that flowered in summer 2022 (1,111) – an interesting note considering exPt01 was burned the spring of both 2022 and 2023. In summer 2023, we harvested 796 total Echinacea heads in exPt01. We also added 270 additional staples to the experimental plot this year, signifying positions were a living plant has not been found for over three years.

Some numbers for experiments within exPt01

Inb1: The INB1 experiment investigates the relationship between inbreeding level and fitness in Echinacea angustifolia. Each plant in experiment INB1 originates from one of three cross types, depending on the relatedness of the parents: between maternal half siblings; between plants from the same remnant, but not sharing a maternal or paternal parent; and between individuals from different remnants. All individuals were planted in 2001. We continued to measure fitness and flowering phenology in these plants. In 2023, of the original 557 plants in INB1, 85 were still alive. Of the plants that were alive this year, 24 of them were flowering; this count is down from summer of 2022 where 40 of the plants were flowering.

qgen: The qGen1 (quantitative genetics) experiment in p1 was designed to quantify the heritability of traits in Echinacea angustifolia. We are especially interested in Darwinian fitness. Could fitness be heritable? During the summer of 2002 we crossed plants from the 1996 & 1997 cohorts of exPt01. We harvested heads, dissected achenes, and germinated seeds over the winter. In the spring of 2003 we planted the resulting 4468 seedlings (this great number gave rise to this experiment’s nickname “big batch”). 1,417 plants in qGen1 were alive in 2023. Of those plants, 298 flowered this summer.

Other plots:

exPt02: To examine the role flowering phenology plays in the reproduction of Echinacea angustifolia, Jennifer Ison planted this plot in 2006 with 3,961 individuals selected for extreme (early or late) flowering timing, or phenology. Using this phenological data, we explore how flowering phenology influences reproductive fitness and estimate the heritability of flowering time in E. angustifolia. In the summer of 2023, we visited 1,855 positions of the 3,961 positions originally planted. We measured 1,283 living plants, of which 118 were flowering, with a total of 148 flowering heads. In the fall, we harvested 67 heads from exPt02. The large difference between the number of heads and the number harvested has to do with high levels of seed predation, mainly by ground squirrels. Last year, Will, Jennifer, and other members of Team Echinacea published a paper in the American Journal of Botany using data from exPt02 – check it out hereLocation: Hegg Lake WMA

exPt04: Experimental plot 4 was planted to gauge whether Echinacea from small remnant populations could be genetically rescued via an outcross to larger, more genetically diverse populations. Caroline Ridley and other members planted this plot in 2008. We did not visit exPt04 this year. Location: Hegg Lake WMA

exPt05: The only experimental plot planted at Staffanson Prairie Preserve (SPP), exPt05, was planted to compare progeny of maternal plants from burned and unburned sections of SPP. There were 2800 plants planted originally, but high mortality made it impractical to visit the plot row-by-row. Now, we and treat the plot like demography. We use our survey-grade GPS to find plants in exPt05 that have previously flowered and add more plants to the stake file if new plants in the plot flower. In 2023 we found 11 living plants, none of which were flowering! We did locate one new flowering plant within the plot boundaries. Location: Staffanson Prairie Preserve

exPt08: Team Echinacea established quantitative genetics experiments to quantify additive genetic variance of fitness in Echinacea, with the idea that we can estimate evolutionary potential of study populations. The maternal parents of qGen2 and qGen3 are plants in the 1996, 1997, and 1999 cohorts. These plants were crossed with pollen from plants in remnants to produce seed for qGen2 and qGen3, which now inhabit exPt08. Originally, 12,813 seeds were sown in the common garden. Seeds from the same cross (shared maternal and paternal plants) were sown in meter-long segments between nails. A total of 3,253 seedlings were originally found, but only 385 plants were found alive in 2023. There were 15 flowering plants in 2023, and 15 heads. On a side note, one additional flowering plant was found in t-plot, and we harvested three heads from that. Location: Wagenius property

Experimental plot management:

  • Burned exPt01 (3 May 2023) and exPt08 (17 May 2023)
  • Replanted pedicularis in exPt01 and exPt10, augmenting Drake’s experimental treatments (replaced ones that died)
    • Dropbox/teamEchinacea2023/z.scanned/replantPedicularisDatasheetWithEchStatusScanned2023-06-21.pdf”
    • Dropbox/teamEchinacea2023/z.scanned/replantPedicularisDatasheetWithEchStatus2Scanned2023-06-21.pdf
  • Planted plugs in ditch west of exPt01
  • Broadcast seed in p8 after the spring burn and in the fall, including Comandra umbellata
  • Stuart trimmed flowering A. gerardii and S. nutans just north of tplot
  • Some plots in hegg (not exPt02) got run over by heavy machinery
  • We did not:
    • Treat sumac
    • Weed in exPt01 (except hawkweed)
    • Treat ash in exPt08, but we noticed that ash south of plot responded favorably to last year’s treatment

Details

  • Start year: Differs between experiment, see above. First ever experimental plot was in 1996.
  • Location: Differs between experiment, see above.
  • Overlaps with: …everything!
  • Data collected: Raw measuring data can be found in cgData repository. Processed data will be uploaded to SQL database. Currently, SQL database has measuring data up until 2022.
  • Samples or specimens collected: See above for total harvested heads in each plot.
  • Products: Many publications and independent projects.

2022 Update: Aphid addition and exclusion

In summer 2022, Team Echinacea continued the aphid addition and exclusion experiment started in 2011 by Katherine Muller. The original experiment included 100 plants selected from exPt01 which were each assigned to have aphids either added or excluded through multiple years. The intention is to assess the impact of the specialist herbivore Aphis echinaceae on Echinacea fitness.

In 2022, Emma Reineke and Kennedy Porter conducted the aphid addition and exclusion project. They located 24 living exclusion plants and 17 living addition plants. Similar to the past two years, they did not find any aphids in exPt01, so they started to introduce a new population of Aphid echinaeceae into ExPt1. Learn more in the summer aphid update.

  • Start year: 2011
  • Location: Experimental Plot 1
  • Overlaps with: Phenology and fitness in P1
  • Data collected: 
    • Plant status (basal, flowering, not present), aphids present, ants present, herbivory (number of leaves significantly chewed on), and the number of aphids added/removed (depending on specific treatment)
    • Protocols and datasheets are located at ~Dropbox\aphidAddEx\aphids2022
  • Samples collected: NA
  • Products:
    • Andy Hoyt’s poster presented at the Fall 2018 Research Symposium at Carleton College
    • 2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
    • 2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads

You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.

Finding (or Not Finding) Aphids – Aphid Addition/Exclusion Update 2022

Since 2011, Team Echinacea has been studying how the presence (or absence) of the specialist herbivore Aphis echinaceae has an impact on Echinacea fitness. This summer, Kennedy and I (Emma) have been tasked with running the project. Originally, 100 heads were included in the study. This summer, only 41 plants are still present, with 17 addition plants and 24 exclusion plants. At the beginning of the summer, Kennedy and I searched to see if we could find any aphids, regardless of whether the plants were a part of the addition or exclusion treatment. We found exactly none, the same as last year. After consulting with Stuart about the conundrum, we decided to introduce a new population of Aphid echinaeceae into ExPt1, where the project is located. Multiple times a week, Kennedy and I went into prairie remnants, carefully gathered the aphids, then brought them back and placed them onto the living addition plants. Below is a graph of the aphid population growth on these 17 plants, with the red line being the average.

Most of the plants have now received between 70 and 80 Aphid echinaeceae since the 20th of July, with most plants having at least a few living each time we visit the plant. On one plant we even found an ant! Overall, it will still take some work to establish a new population, but we seem to be off to a good start.

2021 Update: Aphid addition and exclusion

Team Echinacea continued the aphid addition and exclusion experiment started in 2011 by Katherine Muller. The original experiment included 100 plants selected from exPt01 which were each assigned to have aphids either added or excluded through multiple years. The intention is to assess the impact of the specialist herbivore Aphis echinaceae on Echinacea fitness.

In 2021, the aphid addition and exclusion project was conducted by Allie Radin with occasional help from other field crew members (often Emma Reineke). They located 26 living exclusion plants and 17 living addition plants. The experiment was conducted from July 9th to July 23rd, with the final visit consisting only of searching for aphids. No aphids were seen or moved in exPt01 this year.

Once again, there were very few aphids (actually, none) in exPt01. This is the second year in a row of missing aphids, raising other questions about where the aphids have gone, let alone their impact on the Echinacea plants. Allie and the team searched the experimental plot thoroughly to make sure no potential aphid hiding spot was left unturned. This included large plants from this year and last year, this year’s flowering plants, and plants which had aphids in previous years. Despite low aphid numbers, other insects such as beetles and thrips were present in the plot.

  • Start year: 2011
  • Location: Experimental Plot 1
  • Overlaps with: Phenology and fitness in P1
  • Data collected: Scanned datasheets are located at ~Dropbox\aphidAddEx\aphids2021
  • Samples collected: NA
  • Products:
    • Andy Hoyt’s poster presented at the Fall 2018 Research Symposium at Carleton College
    • 2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
    • 2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads

You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.

2020 update: Aphid addition and exclusion

Team Echinacea continued the aphid addition and exclusion experiment started in 2011 by Katherine Muller. The original experiment included 100 plants selected from exPt01 which were each assigned to have aphids either added or excluded through multiple years. The intention is to assess the impact of the specialist herbivore Aphis echinaceae on Echinacea fitness.

The 2020 aphid team was Anna Allen and Allie Radin. They located 25 living exclusion plants and 16 living addition plants. The experiment was conducted from July 6th to August 19th, with the final visit consisting only of observation. Aphids were moved only during four visits from late July to mid-August due to late arrival and low numbers of aphids. Only one or two aphids were applied to each plant during each visit. They recorded the number of aphids present in classes of 0, 1, 2-10, 11-80, and >80. They also recorded the number of aphids added.

Aphids on an Echinacea leaf

Start year: 2011
Location: Experimental Plot 1
Overlaps with: Phenology and fitness in P1
Data collected: Scanned datasheets are located at ~Dropbox\teamEchinacea2020\allisonRadin\aphidAddEx2020.

Products:

  • Andy Hoyt’s poster presented at the Fall 2018 Research Symposium at Carleton College
  • 2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
  • 2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads

You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.

2019 update: Aphid addition and exclusion

In summer 2019 Team Echinacea continued the aphid addition and exclusion experiment begun in 2011 by Katherine Muller. The original experiment included 100 plants selected from experimental plot one to have aphids added and excluded through multiple years. The intention was to assess the impact of specialist herbivore Aphis echinaceae on Echinacea fitness.

This year Erin and Shea managed the project. They located 15 living addition plants and 22 exclusion plants. The experiment was conducted from July 8th to August 16th. Erin and Shea performed addition and exclusion twice a week for a total of 10 events, with the final visit consisting only of observation. The number of aphids applied to each plant depended on how many could be obtained and varied between five and 10. They recorded the number of aphids present in classes of 0, 1, 2-10, 11-80 and 80<. They also recorded the precise number of aphids added. Erin and Shea found that natural hair paintbrushes were more effective than synthetic and trimmed the brushes down so fewer than half the hairs remained.

Aphids were gently pushed into petri dishes using paintbrushes

Start year: 2011

Location: Experimental Plot 1

Overlaps with: Phenology and fitness in P1

Data collected: Scanned datasheets are located at ~Dropbox\teamEchinacea2019\aphidAddEx2019\aphidAdEx2019Datasheets.pdf. The paper sheets are located in the CBG common area filing cabinets in a manilia folder labeled “Aphid ad/ex 2019,” located next to the 2018 aphid folder.

Products:

  • Andy Hoyt’s poster presented at the Fall 2018 Research Symposium at Carleton College.
  • 2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
  • 2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads

You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.

2018 update: Aphid addition and exclusion

This summer Team Echinacea continued adding and excluding aphids to plants in the experiment that Katherine Muller started in 2011. Katherine Muller randomly designated a sample of 100 Echinacea plants in experimental plot 1 for either aphid addition or removal.

Andy managed the project for the team in 2018, making sure that aphids were removed from the exclusion plants, and added to the addition plants. Twice a week, Andy (and occasionally Morgan) visited every plant in the study, recording the number of aphids, ants, and leaves infested. There remain 54 plants in the aphid study, 26 from the aphid addition plants and 28 from the exclusion plants. The data for this year will be added to the ongoing dataset.

Aphis echinaceae is a specialist aphid that is found only on Echinacea angustifoliaRead more about this experiment.

 

That’s a lot of aphids!

Start year: 2011

Location: Experimental Plot 1

Overlaps with: Phenology and fitness in P1

Data collected: All sheets describing the addition and removal of aphids from echinacea are stored in two places. All physical sheets are in Stuart’s manila folder titled “Aphid Add/Ex 2018.” Additionally, all data from the sheets are present in the aphidAdd2018Master and aphidEx2018Master. The exact path of this file may change but is currently ~\Dropbox\teamEchinacea2018\andyHoyt\aphidAddEx2018\aphidDataAllYears

Physical specimens: We harvested 25 flowering heads from this experiment that will be pulled from the normal ACE processing and pushed through faster. This is so we can more quickly determine achene counts and proportions of full achenes.

Products:

  • Andy Hoyt’s poster presented at the Fall 2018 Research Symposium at Carleton College.
  • 2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
  • 2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads

You can read more about the aphid addition and exclusion experiment, as well as links to previous flog entries mentioning the experiment, on the background page for this experiment.

Aphis echinaceae at Carleton’s Fall Poster Symposium

The aphids were a hit at Carleton’s Summer Research Symposium.

At the Carleton College Summer Research Symposium on October 26th, I presented a poster on my work on the aphid addition/exclusion experiment. Over the summer, I administered the aphid addition and exclusion treatments for the experiment and collected data on leaf senescence and herbivory on plants in the study. Since August, I have been developing an aster model in R to analyze differences in fitness between these two experimental groups. Preparing the aster model for my project was quite a bit of work, but I learned more about R, statistical analysis, and plant-herbivore interactions in the process. Interestingly, Aphis echinaceae has not had an impact on plant fitness over the 8 years of the study.

I am excited to see how the experiment progresses in the coming years, and how the addition of data on seed set affects the results of future fitness models. Quite a few visitors to the symposium were also interested in the results of my analysis and my experience working with the aphids. It was a pleasure to represent the Echinacea Project at Carleton and to have a chance to share the fantastic work the team did over the summer.

A Farewell to Aphids

This morning the much-diminished Team Echinacea (Stuart, Kristen, Lea, Michael, and I) gathered at the Hjelm house to start the day. Lea went to Staffenson Prairie Preserve to measure the flowering phenology of Liatris and Solidago plants. Michael and Kristen began to prepare experimental plot 8 for management in the coming year. The team will treat rogue Ashe trees and collect and broadcast the seeds of several prairie plant species in this plot. This is part of an ongoing effort to ensure that the plant community within the plot is consistent throughout.

Meanwhile, I assessed the leaf damage and senescence of plants in the aphid addition/exclusion experiment in p1. This was the final component of the fieldwork involved in this experiment for the season, and the last step in my independent project before I begin statistical analysis. The next step is to gauge fitness differences between plants in the aphid addition and exclusion treatments by constructing an aster model. While it was exciting to finish this aspect of the project, I will miss spending time with my Aphis echinaceae friends.

Over lunch the team prepared for inclement weather by sharing our experiences of intense weather events. After that, Kristen presented an update on her master’s project. She shared some intriguing preliminary results about the nesting preferences of native ground-nesting bees. We are all looking forward to the results of her study! Due to the rainy weather, the team was ready to call it a day after Kristen’s presentation. We held a short meeting to plan next week’s schedule and then headed home for the weekend.