Pogonomyrmex barbatus, the Red Harvester Ant

• Native to the deserts of the SW USA.

• Complex cuticular system of “scent”involved in nestmate recognition.

• Goal: investigate role bacteria play in thissystem.

Setup for main experiment:

• Crush nestmates, culture in LB.

• 5 “dip” treatments: rifampin (antibiotic), microbial LB “broth” (bacteria), water, LB,and marked (controls).

• After dip, test aggression/rejection from untreated nestmates.

Dip “Ingredients”:

Microbial Augmentation Leads to Rejection

Secondary Assay: Survivorship

• Tested temporal survivorship of each treatment group.

• Reduced survivorship for bacterially-augmented ants?

• Antibiotics didn’t decrease survivorship.

Conclusions and motivation for expanded research:

• Augmented ants rejected, aligns w/ hypothesis.

• Antibiotic treated ants not rejected; contradicts hypothesis, but aligns w/ past studies.

• Social immunity as function of microbially-mediated recognition.

Acknowledgements

Dr. Andy Dosmann

Stanford OHS Science Fair 2016

Feedback Form

Name: Nassim Bahet

Grade level: 12

Subject: Biology

Project: Behavioral ecology of red harvester ants

Instructor A: way to get right into it. your lead slide says a lot, and sets up your talk very efficiently. Nice simple graph of results :) The conclusions are concise and your presentation of them seemed really well reasoned. Overall very good progression from introducing your topic/treatments to results to conclusion, you kept it moving and told your story well. It’s cool that you’re learning so much about your study organisms too, good answers to the Q’s after your talk.

Instructor B: Your images were a good aid to your explanations and helped your audience visualize the experiment. You did a great job fitting a large amount of information, data, and conclusions into a brief time. You kept things moving with clear explanations. You answered a diverse set of questions with a good mix of knowledge you have, hypothetical explanations, and deferment to other expert sources. Very professional!

Instructor C: Fantastic project! My only real complaint is that you need to watch text chat to see if people are asking you questions because a lot of us curious about it because it was so interesting. Your slides were very clear and professional, and your explanation of your method and results was also excellent. Great project and great presentation! I’m really proud of how far you’ve come as a scientist!

Instructor D: This was a real pleasure to watch, and I’m proud to be teaching at your school! The visuals are great throughout, and your visual, written, and verbal components were really well integrated. This is a really cool experiment, and while it’s complex, you explained it with great skill. It seems to be a rare situation where you’re able to convey the essential wonder behind the science (interesting!! Why did that happen??) here to a lay audience. As you saw, your presentation motivated a ton of interesting, and you did a really great job addressing the many questions you got after the presentation. Thank you!

Instructor E:

Instructor F:

Instructor G: This was a fascinating topic and a great project. I liked the clear way you motivated your project and laid out its goal right on the very first slide. Your visuals were great, and your delivery was excellent. Ants have so many interesting and poorly understood behaviors. Your result that antibiotics did not increase mortality rates is fascinating and provides a great opening and opportunity for further research! I hope you will continue this project, and that we will get to hear more about it in the future!

Instructor H: Cool! What chemical compounds are involved in recognition is this known? Can you use this to motivate your method. Controls for use of markers? Good presentation style.