Meet BluMorpho, a tiny $175 tracking device that weighs just 60 milligrams, less than a grain of rice. It is solar powered and is being used by scientists to track movements of tiny organisms such as bees, butterflies and other insects.
Cellular Tracking Technologies, the maker of BluMorpho, released the wireless sensor tag in 2023 but the company just now hit the big time, featured in an article in The New York Times that describes its use in tracking the migration of monarch butterflies across North America. What is special now in late 2025: Scientists used BluMorpho beginning in mid-September to actively monitor individual insects on their journeys from Ontario to central Mexico.
Scientists in 20 partner organizations tagged more than 400 monarchs this fall and began following their journeys, including on a cellphone app from CTT, based in New Jersey. They hope to learn more about their in-flight behaviors, which could help decode why their numbers are decreasing.
How BluMorpho works
Weight is everything with BluMorpho. At 60 milligrams, that is a tiny amount, but still a significant portion of a typical monarch, which weighs in at 500 to 600 milligrams. A big factor in keeping the weight down is solar power, so there’s no battery to add mass.
Tracking is done via Bluetooth-equipped smartphones (2.4 GHz) within 300 feet and other dedicated wildlife receivers along the flight. Scientists are able to get high-resolution, near-real-time data on individual butterflies with transmissions every second. Before November 2024, tracking stations in the Motus Wildlife Tracking System and Terra mini base stations were used for tracking, which was not sufficient to study individual butterflies along the entire pathway.
Everything changed a year ago when a butterfly named Lionel was equipped with a new bit of programming code, called Blu+ on BluMorpho, which allowed Lionel to tap into crowd-sourced location networks, which numbered in the hundreds as it flew from Cape May Point, NJ, to St. Augustine, FL.
“Lionel’s track was a pivotal moment,” said Sean Burcher, senior R&D scientist at CTT and the Science Director of Cape May Point Arts & Science Center. “With hundreds of millions of devices all acting as passive receivers, we were able to watch the fine-scale movements of Lionel in near-real-time.”
Then, nearly a year later in September, Canadian researchers deployed 30 Blu+ transmitters at Long Point, Ontario, and were able to detect monarchs streaming southwest, crossing Lake Erie. That early flight helped scientists realize they could see many butterflies at many locations and that data would show how they move through the landscapes of urban and suburban areas and, importantly, how they respond to weather. In October, 400 transmitters were deployed from Canada to Cuba.
As of Nov. 9, tagged monarchs had entered the Monarch Buttery Biosphere Reserve in Mexico. Some of the tagged monarchs are expected to survive the winter, tags in place, to return to the north.
Building BluMorpho as both a wireless transmitter and sensor tag
In an interview with Fierce, Dr. David La Puma, Director of Global Market Development at CTT, said BluMorpho transmits a proprietary packet which includes the tag’s ID and other corroboration material as well as ambient temperature and solar voltage. While BluMorpho acts as a wireless transmitter over 2.4 GHz it is not operating as Bluetooth certified. It also acts as a sensor tag because it communicates temperature and solar voltage, he said.
The packet information is decoded by CTT’s proprietary receivers over the Motus network, a global radio receiving network used by scientists. The data can then be pushed up to a server and shared with all the research participants. CTT has a second packet that distributes public and private key information which is distributed over IoT networks through an app which “turns millions of smartphones into receivers and that’s where we get orders of magnitude growth in location.” The temperature and solar voltage sensor data is communicated only through dedicated receivers.
Other companies make small transmitters for use with wildlife tracking, but La Puma said CTT is the only company using 2.4 GHz. “Our philosophy has always been how to make things smaller and our objective was to study monarchs,” he said. It’s been a long time coming and this is a holy grail moment. So many species will benefit. Ok, we knew we had to get small but also be ubiquitous.”
CTT was founded in 2007 by a cross-section of scientists and engineers and has grown to 36 employees. La Puma is an ornithologist, but like many of the scientists on board brings a keen understanding of the demands of making transmitters for wildlife tracking. The company has a range of products that are mostly assembled in the US or right in New Jersey. Processors and diodes generally come from Asia, while tiny solar panels are made by CTT using automated equipment.
BluMorpho tags are applied to butterflies in a humane fashion by professionals familiar with the process. It often involves slipping glassine paper envelopes over the wings to protect their scales and then eyelash adhesive is applied to the thorax and the tiny BluMorpho tag, which has a trailing antenna.
About Lionel the Monarch and its fantastic flight
Lionel, the first monarch to be equipped with Blu+ programming code, could be the hero of this story. La Puma said he was tracked all the way to Florida to a neighbor’s back yard. Sadly, only monarch wings were found and the BluMorpho transmitter was still functioning nearby-- a year after the flight began. “Seeing Lionel’s flight left jaws dropping on the floor and we were all asking, do we have more data? We were panicked looking for Lionel. They found monarch wings and a tag a year later. Lionel is deceased.”
Give Lionel the credit for the miracle of flying hundreds of miles, but the other achievement is the combination of scientific insights from hundreds of professionals using tiny technology that combines sensors and wireless transmitters light enough for a butterfly to carry.
What’s next for BluMorpho and wildlife tracking technology
While BluMorpho today senses solar voltage and temperature, CTT hopes to add accelerometers, altimeters and pressure sensors to be able to gain more insights about the threats to monarchs. “Our platform can take other sensors, but that adds weight,” La Puma said.
Undoubtedly, more data will help understand diminishing numbers of monarchs. “You can’t pinpoint it on one thing. It’s a combination of factors, no doubt,” he said. In the Midwest, farms stretch hundreds of miles where prairies once thrived, supporting milkweed plants that monarchs thrive on.
“We’ve lost the host plant and there’s an increase in pesticides and herbicides, which has got to have a major impact. Combine that with changing climates, plus many monarchs fly to the mountains of Mexico where they need that habitat, which Mexico has worked hard to protect. We only have data this year to look at the effects of weather but will have more data in multiple years. Monarchs are definitely affected by weather, which includes their heat threshold. The effects of heat, drought, more heat waves and other extreme weather would be negative on them. Getting to Mexico is part of the equation with wind and headwinds, which requires more energy.“
From the looks of early data, the monarchs that migrate from Canada to Mexico, a distance of more than 2,500 miles, are just beginning to speak.