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 angustifolia. Read 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.