Scientists concerned with a recently identified “Insect Apocalypse” have discovered an alarming rate of decline in new research comparing recent ant populations on the Fijian archipelago to museum collections, as reported in a new paper published in Science.
With their major roles in crucial ecosystem functions, such as pollination and decomposition, the declines in insect populations discovered in recent studies are a significant cause for concern. The new work led by the Okinawa Institute of Space and Technology (OIST) investigates the decline on a much longer timescale, relying on comparative data collected from old specimens.
Studying the Insect Apocalypse
While the majority of biodiversity monitoring work is centered on larger, more readily monitored animals, the OIST researchers zoomed in on an important and poorly understood issue: the Insect Apocalypse. Knowing that island ecosystems are biodiversity hotspots, understanding these population changes over time offers critical insight into what may be occurring on a larger scale.
The OIST team investigated the evolution of the Fijian ant populations by studying genomics found in existing museum specimens and some of the team’s own collection efforts. With the challenges inherent to tropical fieldwork and the difficulty in maintaining continuous surveys, combining decades of entomology research as the basis for the project was the most effective way to proceed.
Working with Old DNA
“It can be difficult to estimate historical changes to insect populations, because with few exceptions, we haven’t been directly monitoring populations over time,” said co-author Dr. Evan Economo of OIST and the University of Maryland. “We take a novel approach to this problem by analyzing the genomes of many species in parallel from museum specimens collected recently. The genomes hold evidence of whether populations are growing or shrinking, allowing us to reconstruct community-wide changes.”
While the museum collections offer a view of Fijian ants over time, relying on the material has one significant drawback: DNA degrades over time. To meet this challenge, the OIST team turned to the field of museumomics, which, as the name implies, adapts genomic techniques to address the specific challenges associated with old samples. Tiny fragments of the DNA were compared with these sequencing techniques across thousands of ants representing more than one hundred unique species.
A History of Ants
According to their results, since humans began arriving on the islands 3,000 years ago, the ant population has undergone drastic changes, with 79% of endemic species showing decline and major growth in new species introduced by colonists. Following more recent colonization, the islands began to experience the most severe population disturbances, as settlement, agriculture, and global trade reshaped the local ecosystems.
“Being closed, isolated ecosystems, islands are expected to feel the effects of human impact faster, so they are kind of a canary in the coal mine,” notes lead author Dr. Cong Liu.
From the team’s analysis, 65 colonization events emerged, identifying the moments when new ant species arrived on an island. Colonization was not the sole culprit, as their work also discovered the periods when species arrived on their own millions of years ago. The data provided the basis for the team to determine the comparative rise and decline of various species over time, emphasizing the decline of native populations in favor of new arrivals. As native species evolved to become more specifically adapted to their unique environment, they were less able to thrive among the changing post-colonial conditions than imported species from other areas.
Keeping an Eye on the Insect Apocalypse
Researchers involved in the study hope that their work will be carried on by others, to bring further understanding to the Insect Apocalypse, which may be put into action with future conservation practices.
“This study also highlights the importance of biodiversity and museum collections,” explains co-author Professor Alexander Mikheyev of the Australian National University. “As our scientific toolbox expands, there is more and more information that we are able to capture from biodiversity collections, so it’s essential that we continue investing in and maintaining these vital resources.”
OIST is also pursuing more localized research in the form of acoustic monitoring and insect trapping through the Okinawa Environmental Observation Network.
“Insects are essential for the environment,” emphasizes Prof. Economo. “As scientists, we need to play our part in their protection, and provide and analyze the relevant data to ensure the long-term integrity of our ecosystems”.
The paper, “Genomic Signatures Indicate Biodiversity Loss in an Endemic Island Ant Fauna,” appeared in Science on September 11, 2025.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.