Day 8: The Day of Stress – An Instructor's Perspective

We are wrapping up our time at Finca La Anita today.  The students have likely learned one of the biggest lessons in science to date – research is often accompanied by failure and stress.  Today was the final opportunity to wrap up their research projects, analyze data, and present to an audience.  And some groups discovered that not all goes as planned, and yet they still need to pull together a presentation.  What follows are highlights from each presentation.

Tortugas Blancas:  Psuedonocardia vs. Escovopsis in 44 Hours (Jaci, Tim, Jake B, Joseph)

Pseudonocardia is bacteria used to fight off the Escovopsis .  Question:  can the pseudonocardia found on the backs of Acromyrmax be used to combat the presence of escovopsis in an Atta colony?  The pseudonocardia was applied through a sprayed solution.  Within a short time the fungal garden had collapsed from the added water leading to the first failure.  Recovery led to analysis of existing fungal growths plated earlier in the week.   

Los Depredadores:  Maic Metabolics  (Shelby, Maddi, Sam H, Jake A)

 Atta Cephalottes ant colonies grow quite large, but only one queen runs the whole show.  Question:  do  metabolic changes occur in an ant colony when stressed by removal  of the queen or larvae?  One colony did indicate an increase in CO2 production during these stresses .  Also interesting qualitative observations differ - when the queen was pulled out solo she became very aggressive.  But when pulled out with a few ants she was much more docile.  If other ants were pulled out with larvae, they carried them around looking for a good place to put them.

Mighty Churros:  Pheromone Extraction and Fungal Microbes (Tony, Kyle, Sam W, Erin)

In an attempt to find a way to distract leaf cutter ants from the cacao plants, Question1:  can we use a common solvent be used to isolate the trail pheromone?  Crushed ants were soaked in water, ethanol, or salt water.  This solution was then put into a tube connected to a chamber containing 10 ants.  In one colony ants seem to follow the trail which may indicate that the pheromone was in that trail.  But that effect was not seen in the other colony test. 

Question2:  Do ants differ in their external culturable fungal microbiome by role in the colony?  15 plates were swabbed for each ant.  Evidence in examining the plates does not demonstrate a significant difference.  Interestingly, for the both the queen and soldiers, almost no growth was seen at all indicating that the colony is kept very clean.

Los Avispones: Ant Pheromone Control Study (Tyler, Graham, Tate, Delane)

Question:  how effective are the atta cephalotes trail pheromones?  The study was done in the field and made use of an established ant colony with distinct trails.  Boards were set into the trail and left for several hours so ants could establish a pheromone trail.  The board was then flipped 180®.  A second test of depth of trail was done by successively removing soil along the trail.  A count of ants per minute indicates that any change in the trail disrupts the flow of ants.  The disruption in worker ants carrying leaves only lasts a short time until the little worker ants work together to reestablish the trail.  Other interesting observations:  ants would head to discarded soil during the depth test and crawl under the board when flipped in an attempt to follow the pheromone trail.

All presentations were very professionally presented and students responded well to questions presented to them.  For further information on our trip, and the opportunity to ask your own questions, please come to the formal presentations for families, friends, staff, and school board on Wednesday, April 3.  We have a few more days here in Costa Rica.  We head out tomorrow morning for a research station near the beach.  We will update you more on our experiences there in our next post.