A new high-throughput respiration-measuring system lets scientists monitor up to 240 insects and other invertebrates at once, making it far easier to study insects’ resting metabolic rates and how they respond to temperature and climate change. The method is adapted from a commercially available system originally designed to measure oxygen use in laboratory cell cultures. Shown here are the respirometry unit with vials inside an incubator (A), a firebug in a vial (B), three fruit flies in a vial (C), spiders in a set of larger vials (D), and a multidevice setup of the respirometry unit and one extension set. (Adapted from figure originally published in Mouret et al. 2026, Journal of Insect Science)

By Grant Bolton, Ph.D.

Grant Bolton, Ph.D.

An insect at rest may not sound very interesting to an insect behavioralist or ecologist. But to an ecophysiologist, it’s exactly where they want their specimen.

All organisms expend energy, whether they’re searching for food, escaping predators, reproducing, or communicating with other organisms. Even at rest, an insect has to spend energy simply maintaining itself. Researchers can estimate that baseline energy expenditure, or resting metabolic rate, through its respiration (i.e., breathing). How much oxygen does it consume and how much carbon dioxide does it produce?

Understanding metabolic rate can help entomologists investigate how insects allocate limited energy, how individuals and species differ physiologically, and how their metabolism responds to environmental conditions such as temperature. Those questions are becoming increasingly important as researchers try to understand how insects may respond to changing environmental conditions.

The problem is that measuring respiratory metabolism can be slow. Traditional respirometry methods can make collecting large datasets across many individuals or temperatures a very time-intensive process.

Researchers at the Station d’Ecologie Théorique et Expérimentale in France wondered whether they could scale up those measurements without reinventing the proverbial wheel. Their solution was to adapt a commercially available system originally designed to measure oxygen use in laboratory cell cultures. Their results, published in August in the Journal of Insect Science, show the system can monitor respiration in as many as 240 invertebrate samples in parallel.

Elvire Bestion, Ph.D., who supervised the study, understands firsthand how quickly the workload can grow. “An example of an experiment of mine compared 24 populations, five individuals per population, across 10 temperatures, and multiply that by several species,” she says. “As you can see, the sample size adds up quickly!”

Bestion first encountered the PreSens system while studying phytoplankton during her postdoctoral research. When she later began working with arthropods, she wondered whether the same scalable system could work for insects.

“I wasn’t sure it would work as well as for phytoplankton, but my first trials were conclusive,” she says.

Before Bestion and colleagues could take advantage of the system’s higher throughput, they first had to show that it could reliably measure invertebrate respiration. They tested it with terrestrial species including crickets, firebugs, wolf spiders, ants, woodlice, snails, and fruit flies, as well as aquatic amphipods. Measurements were repeatable over several hours and across multiple days, and respiration followed expected relationships with body size and temperature. Even fruit flies could be measured, although the smallest individuals sometimes needed to be grouped together to produce a detectable signal.

That result surprised Bestion: “Being able to measure metabolism on Drosophila, even if I had to have at least two individuals together, better with three to four. That was neat.”

The researchers then used the system to build a thermal performance curve for 35 snout beetles tested across 11 temperatures from 18 to 41 degrees Celsius. Metabolic rate increased with temperature, peaking near 39.3 degrees C and declining sharply beyond it.

Why Throughput Matters

The larger implication is not necessarily that researchers can measure insect respiration faster. Rather, higher throughput may allow entomologists to ask the same questions, but at a larger scale. Experiments comparing individuals, populations, species, or multiple temperatures can quickly require hundreds of measurements. A system capable of monitoring up to 240 samples simultaneously could make those studies more practical, particularly when researchers want to construct detailed thermal performance curves.

For Bestion, those thermal performance curves are the system’s “killer application.” With multiple incubators, researchers can even measure several temperatures in parallel.

“In the urgent context of climate change, better understanding the thermal physiology of species and how species can adapt or not to changes in climatic conditions is crucial,” she says.

Limits Remain

High throughput doesn’t eliminate respirometry challenges. Temperature must be carefully controlled because the oxygen sensors are temperature-sensitive, and researchers need adequate acclimation periods and control vials. Aquatic experiments also require accounting for microbial respiration in the water. Closed chambers can also develop low oxygen or elevated carbon dioxide during longer experiments, potentially influencing the animals being measured.

Those constraints also limit the kinds of questions the system can address. “I would not use the system if I was interested in long-term questions such as circadian rhythms of respiration,” Bestion says. “However, I believe that the system has great potential for studying of the consequences of global changes.”

Measuring insect respiration isn’t new. However, this approach changes how many measurements researchers can collect at once. By adapting existing technology rather than developing a new system from scratch, the researchers have given entomologists another tool for studying metabolic responses across individual organisms, species, and temperatures. The payoff may ultimately be less about measuring insects faster and more about making larger physiological questions more practical to investigate.

Grant Bolton, Ph.D., is a freelance writer and technical marketing consultant with a Ph.D. in entomology based in the Missouri Ozarks. Email: [email protected].