Project Results

Desiccation resistance is defined as the ability of an organism to survive periods without water or to reduce water loss. Most research on insect desiccation resistance has focused on arid environments, but tropical insects can also face desiccation challenges. Neotropical ecosystems exhibit the most diverse and abundant biodiversity on the planet but are heavily impacted by climate change because of high degrees of climatic specialization.  Army ants are keystone predators and are found both in tropical rainforests as well as in tropical dry forests in northern Costa Rica. We tested whether Eciton differs (intra- and interspecifically) in desiccation resistance across this expanse.  I tested the desiccation resistance across five species of genus Eciton. I performed desiccation assays in workers of species Eciton burchellii, Eciton hamatum, Eciton lucanoides, Eciton mexicanum, and Eciton vagans on the grounds of high-precipitation La Selva Biological Station and in the lower precipitation site of Santa Rosa National Park. I report that E. burchelli workers has a higher desiccation resistance among the five species, but an interesting patterns that widen our understanding of both army ant physiology and tropical ecology was also found, where the ants of the lower precipitation site showed a higher tolerance than the ones in the high-precipitation, even when in both places where the same species.  These findings have the potential to aid conservation efforts of these species, and ecosystems, but may inform more efficient conservation strategies for the tropics in general.

About This Project

I am studying army ants of the genus Eciton in Costa Rica. These insects will give us better light on how to fight against climate change in tropical forests, especially in the tropical rain forest. Army ants are extremely sensitive to humidity variations, but, what will happen if this pattern changes? How the worker ants will respond? With low-budget equipment, I plan to measure how these ants will respond to lack or low levels of humidity.

Ask the Scientists

What is the context of this research?

Army ants of the genus Eciton are top predators in tropical rainforests. The ants have evolved to cope with challenging abiotic conditions including desiccation events. Most of the desiccation studies have been conducted in arid zones. However, with climate change, all these patterns are changing so fast that the species might not be able to cope them. If we manage to know more about how desiccation resistance works in Eciton army ants, we can not only help to protect the species itself but also, the entire ecosystem, because as top predators, their absence will cause cascading effects.

What is the significance of this project?

This project is important to help the tropics. If we find more efficient ways to manage and preserve not just one species, but the entire ecosystem, we will be more efficient in our efforts. This low-budget experiment allows to gather reliable data to find out about the desiccation resistance of army ants and this desiccation resistance. Also, this information can be a base to further investigations about similar topics in other species in different places, because climate change is a global threat. Based on this reasons ant the context, I propose to study how workers of different species of Eciton differ in desiccation resistance.

What are the goals of the project?

The project aim to establish the desiccation resistance of army ants in Costa Rica. I will collect workers of Eciton burchellii, E. hamatum, E. lucanoides, E. mexicanum, & E. vagans. Ants will be placed in a chamber through which 0% RH air will be pushed, using an air pump & a column of Drierite. The Drierite is connected to a filter that is connected to a split channel that will distribute the air to 6 plastic syringes (10ml e/o) & had been modified as chambers to put the ants. I will monitor worker conditions hourly, recording the time to death of each individual. I will have positive controls with water instead of drierite.I need funding for the field part of the project that will be developed between June and July of 2023.