American researchers have developed an inexpensive device that will allow them to study the behavior and activity of insects, the largest group of organisms on the planet. With species inhabiting every continent, including Antarctica, scientists know very little about when most insects are awake and active, which is especially true for nocturnal species that fly beneath the dark veil of darkness.
“We study butterflies, bees and ants because we can see them, but there are hundreds of thousands of nocturnal insects, all of which have been nearly impossible to track so far,” curator Akito Kawahara said. from the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History, said in a study published Feb. 24.
“Knowing when organisms are most active is the basis for understanding their behaviors and circadian rhythms – patterns that determine when they forage for food, reproduce, pollinate flowers and more. , it is more difficult to predict or determine how changes in the environment, such as increased light pollution, might affect them,” he explained in a report posted on the museum’s website.
“But the smaller the animal, the harder it is to track. Insects are generally too small to carry tracking devices that would tell biologists their movements. Instead, researchers have to lure them with bait or lights, which paint only a partial picture of their activity,” he noted.
“You might think a moth is nocturnal because it has only been seen at night, but that doesn’t mean it hasn’t come out during the day. ‘just wasn’t seen,” said lead author Yash Sondhi of the Florida Department of Biology. International University.
For years, Kawahara tried to find a portable device that would allow him to track insects while working in the field with his collaborator Jesse Barber at Boise State University, sometimes even trying to outsource the work to companies in the hope that they could build it for him. But equipment sensitive enough to measure the delicate movements of the smallest moths while being durable enough to withstand harsh environments and remote locations without electricity or the internet has proven difficult to design. “I offered Sondhi to try making it himself, and he was able to build the device we had always imagined,” Kawahara said.
Sondhi has put together a microcomputer, open-source motion tracking software, sensors, a camera, and all-important infrared lights that won’t disturb or confuse insects. He housed all of this in a wire cage that looks like a laundry basket, and the wearable locomotion activity monitor, called pLAM, was born.
It can be built for less than $100, a tiny fraction of lab technology that costs between $1,000 and $4,000.
After using pLAM to monitor insect activity in the lab to make sure the equipment was working properly, Sondhi and Kawahara tested it on a research trip to Costa Rica. They collected 15 species, placing between four and eight insects of each in the activity monitors.
According to Sondhi, one of the most interesting examples was a species of tiger moth. It is assumed that these poisonous, brightly colored butterflies come out exclusively during the day, since predators avoid them, and they can move about without fear of being eaten.
However, data from activity monitors revealed that they are also active at dusk. After all, they have to evade other predators that come out after dark, such as bats.
“It was so cool to see the different patterns of activity. Not everything is as black and white as we think. Now we can predict and better understand what happens when insects fly and determine when they are assets and then associate that with their traits,” Sondhi said.
Kawahara is optimistic that the new device will help inform efforts to stave off the recent global trend of insect decline and extinction. “The basic data we need to understand the activity of small insects and other organisms is so limited. We talk about the impact of light pollution, noise pollution and climate change on insects, but we don’t know anything about how it affects their activity because we haven’t been able to monitor the activity of most insect species. This device will allow us to collect that information,” he said. concluded.