Insect declines threaten wildlife far beyond insect world
Major global analysis shows insects provide diverse benefits for other animals – from food and shelter, to protection and even medicines.
From grizzly bears and chimpanzees to geckos and poison dart frogs, the lives of tens of thousands of animal species depend on insects and other invertebrates not just for food. They provide, homes, medicines, sanitation and chemical self-defence, often living alongside each other in mutually beneficial relationships.
Scientists are now warning that widespread insect declines will therefore have far-reaching impacts on other species. An international research team carried out the most comprehensive global scientific analysis to date of the impacts of insects on wildlife, led by the UK Centre for Ecology & Hydrology (UKCEH) and Binghamton University, USA.
The scientists reviewed evidence from almost 300 studies published over the past 75 years relating to land and freshwater wildlife, including mammals, birds, amphibians, reptiles and fish. It found nearly three-quarters of studied wildlife species eat invertebrates – mainly insects – and over two-fifths exclusively so.
Many animals also rely on foods that exist only because insects pollinate plants or disperse seeds. Some species have developed remarkable adaptations for capturing them, from the projectile tongues of amphibians and chameleons to birds that have learnt to remove bee stings before eating them.
But the study, published in Nature Reviews Biodiversity, also identifies many ways that insects support wildlife beyond simply providing food.
- Providing homes: Wildlife use insect-built structures, particularly termite mounds and ant nests, for shelter, protection from predators, breeding grounds or laying eggs.
- Chemical defence: Some animals, such as poison dart frogs, accumulate toxins from the ants and beetles they eat and secrete them, making themselves less appealing to predators.
- Health and sanitation: Insects can reduce disease risk through the removal or drying of dung, which also kills parasites. Beetles prey on the larvae of blowfly and other pests, protecting birds and mammals from biting insects and disease. Chimpanzees apply insects to open wounds and some birds, reptiles, amphibians, rodents and primates use ants for grooming.
The paper’s co-lead author Dr Rob Cooke, a senior ecologist at UKCEH, said: “Our study presents the most holistic picture of interactions between insects and wildlife to date. It highlights the remarkable and often overlooked ways that insects support other animals, and the extraordinary relationships between them.
“Widespread insect declines globally are likely to have far-reaching effects on wildlife. Beyond reducing an essential food source, losses of insects risk changing ecosystems, disrupting pollination and seed dispersal, weakening sanitation, and altering the many interactions that help ecosystems function.
“We therefore hope our research strengthens the message that protecting insect populations is essential for protecting wider biodiversity.”
Helpful housemates
Some species of wildlife live alongside insects in mutually beneficial relationships. Moths have been found in owl and kingfisher nests, where they decompose fur, crushed feathers, pellets and faeces. They also live on the backs of brown-throated sloths where they deposit nitrogen in their fur and spur algal growth, a key food source for their hosts.
The study does, though, also point out the negative impacts. Although insects generally do not eat other animals, it does occur, such as dragonfly nymphs eating tadpoles and small fish and mantids sometimes capturing hummingbirds and other small birds. Ants and wasps have been reported to attack lizards, birds and mammals.
Meanwhile, different species of mosquitoes transmit avian malaria and West Nile virus to birds, or fungus to frogs, and fleas pass on pathogens to mammals.
Dr Eliza Grames of Binghamton University, co-lead author of the paper, concluded: "Changes in insects can have massive consequences for food webs and ecosystems. Declines in insect populations could risk destabilizing some of the most fundamental processes that the natural world depends on."
ENDS
Journal
Nature Reviews Biodiversity
Method of Research
Systematic review
Subject of Research
Animals
Article Title
The importance of insect biodiversity for vertebrates
Insects are essential to vertebrate life — as food, shelter and medicine
Binghamton University, State University of New York biologists co-author a review paper on the importance of insect diversity in a time of decline
Binghamton University
image:
A new paper featuring faculty at Binghamton University, State University of New York, reveals that vertebrates like sloths rely on insects for a variety of purposes.
view moreCredit: “Hoffmann's Two-toed Sloth (Choloepus hoffmanni) 霍夫曼兩趾樹懶 & Sloth Moths (Cryptoses choloepi) 樹懶蛾” by Dash Huang, CC BY-NC-SA 2.0
While insects provide an essential food source for many vertebrate species, they’re more than just a protein-laden snack.
Chimpanzees use them to sterilize wounds, and herons as fishing bait. Sloths rely on moths to maintain the algae in their fur, which they then eat. Birds and reptiles lay their eggs inside the temperature-controlled sanctuary of termite mounds, while some desert frogs reside in ant nests because of the humidity.
“Insects are sometimes called the ‘little things that run the world’ because they are so important to life on Earth,” said Binghamton University, State University of New York Assistant Professor of Biological Sciences Eliza Grames, the co-lead author of “The importance of insect biodiversity for vertebrates,” published Sept. 30 in Nature Reviews Biodiversity. “We often hear about their importance as pollinators, or decomposers, or food for insectivores like birds and bats, but we forget about all the other things they do for us and for other species.”
A collaborative effort with authors from eight countries, the review paper was led by Grames along with Rob Cooke, an ecological modeler at the UK Center for Ecology and Hydrology, and UConn Professor of Ecology and Evolutionary Biology Chris Elphick.
Additional Binghamton authors include Assistant Professor of Biological Sciences Lindsey Swierk and biological sciences alumni Julianna Yager, MS ’25, and Suyeon Jang, ’25. Jang, an undergraduate with a painting minor, also created the paper’s main illustration as an independent study project.
The review article consolidates hundreds of disparate studies conducted across decades, highlighting the importance of insect biodiversity in supporting vertebrate life. The project began in 2022 with the creation of the National Science Foundation-funded Status of Insects: An International Research Coordination Network, a direct result of Grames’ work as a doctoral student in Elphick’s lab.
A better understanding of the diverse roles that insects play in the lives of vertebrates is essential for designing effective conservation strategies. Elphick, an ornithologist, said that he hopes the review will foster increased collaboration between scientists who study vertebrates and those who study insects.
“If you want to have vertebrates, then you’ve got to be thinking about insect conservation, and we don’t do that nearly enough,” he said.
There are an estimated 14 to 30 million species of insects in the world, and they play a major role in the health and function of ecosystems. They provide food to species ranging from hummingbirds to grizzly bears, enable the existence of other food sources through pollination, and produce substances such as honeydew, honey, and wax that are also consumed by other species.
Birds use spider and insect silk in their nests, which they sometimes situate near stinging insects such as wasps for extra protection. More than 200 bird species use crushed ants for grooming, and a variety of vertebrate species time their breeding season to coincide with seasonal insect abundance. Go back far enough, and insects once lived inside dinosaur nests, cleaning them out; it’s a service they still perform in some owl and kingfisher nests, according to Grames.
But few scientific studies consider the decline of insect populations on vertebrate species, other than as a reduction in a species’ food supply, according to the paper. Some insect populations have experienced alarming declines in recent decades, which will ultimately affect the vertebrate species that rely on them.
“We’re losing insects at a rate of about 1-2% per year,” said Grames. “When you scale that up across a few decades, we’re talking about a major change to ecosystems. Insect conservation should be a top priority for anyone worried about the future of biodiversity.”
Journal
Nature Reviews Biodiversity
Method of Research
Literature review
Subject of Research
Animals
Article Publication Date
30-Sep-2026
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