Antlab in Panama

As a student at The Ohio State’s summer “Soil Acarology Course,” this has been my state for the last week:

“Dorsosejugal scissure with 3 arches. Octotaxic system reduced to 4 pairs of very small saccules. On palptarsus eupathidium, acm and solenidion on large apophysis and strongly curved…………….Rostrozetes”

A couplet from a key. The mite course goes something like this. Arrive at lab 830AM. Identify mites until 1030PM. Pretty intense. This is precious knowledge. Only a handful of people in the world know how to look for and look at these tiny arthropods that cover nearly every surface on the planet. Today, we will nearly be finished learning the families of Mesostigmata. We even sorted through July 4th fireworks–granted many of the folks in the class are not Americans–but still, we could hear pounding of the stuff in the sky outside the windowless room.

I realize this note postdates my time on BCI, but I am a night writer and my nights on the island were busy. No, not in that way! I was taking care of ca. 60 ant colonies as part of research investigating why tropical litter ant colonies mature at such small sizes. Amazingly, tropical forests are home to some of the world’s largest (the leaf cutters and army ants) and smallest ant colonies. As a lover of small things, I have become fascinated by twig inhabiting colonies of ants that approach densities of 5 colonies per meter squared but would never be observed while casually hiking.

An ant colony experiences periods of growth, during which the queen produces sterile workers. At various periods during its development, the colony reproduces as the queen produces sexual winged males and females that fly away and mate with sexual ants from other colonies. While many colonies in temperate zones often do not approach “sexual maturity” until they contain 1,000’s of workers, tropical litter colonies routinely reproduce with only 50 workers! By raising colonies in captivity under various levels of resource availability, I sought to understand how food limitation influenced colony life histories (e.g. growth rates and size at maturity).

My project was not without its struggles. During my first BCI month, I refined my culturing techniques—learning what conditions my ants liked and emphatically disliked. For instance, one night after about a month of painstakingly establishing colonies, I made the fateful decision to change their diets to cold-cut turkey. This attempt to standardize supplemented protein unfortunately initiated a bacterial outbreak which killed half my colonies over night. I experienced something a bit beyond chagrin when I saw the last of the living ants writhing in agony. Some times fungi overtook the jell-o diet I had lovingly prepared, while at others, escaped ants searched the lab table for suitable habitat.

Last summer, I sampled insects from meter squared plots in leaf litter, extracting critters in alcohol and then spending the next 6 months sorting them dead under a scope. This summer, I was determined to “get to know” the soil organisms in a more dynamic way. It was wonderfully pleasant to spend late nights in the soil lab, watching ants actively behaving. Each colony, as a “superorganism,” seemed to have its own personality, and as a scientist, I had to refrain from assigning them names! Some routinely foraged en masse, while some subtly sent out major workers. Some organized their garbage into neat piles while others left detritus haphazardly strewn about the brood chambers. They all seemed to wage pitched battles against fungi, and I took it upon myself to serve as their maid, frequently cleaning out their homes.

The island seems a bit distant now, as I have immersed myself in this mite business. Soil mites are a bit frustrating to identify through morphological characters because, being basically blind and tiny, visual cues are not part of their lives in the peacock feather sense. Mite specimens are also usually mounted as crushed pancakes on slides, with heads as fragmented pieces. To the patient observer, however, they are beautiful variations on armored themes. To litter ants they are thought to be breakfast lunch and dinner! But such dynamics will remain fodder for future versions of my research…

Best of luck to Matt and Risa who are still on BCI. I hope they drink a beer on the balcony for me!