Insects play a far more diverse and critical role in ecosystems than merely serving as a food source for many vertebrates, according to a new study published in *Nature Reviews Biodiversity*. The research highlights how insects contribute to protection, sanitation, shelter, and other ecological functions that support a wide range of vertebrate species, including birds, bats, reptiles, amphibians, and mammals.
The study, led by Eliza Grames, assistant professor of biological sciences at Binghamton University, State University of New York, emphasizes that nearly 75% of terrestrial and freshwater vertebrates consume invertebrates, with insects frequently comprising a significant portion of their diets. However, relationships between insects and vertebrates extend well beyond predator-prey dynamics.
Grames and her colleagues document numerous examples of these complex interactions. For instance, chimpanzees have been observed using insects to treat wounds, while over 200 bird species engage in behaviors such as using ants to remove parasites or maintain their feathers. Some birds build nests near stinging insects like wasps, likely to gain protection from predators. Additionally, insects provide shelter; termite mounds and ant nests offer stable microclimates utilized by birds, reptiles, and mammals.
Other curious interactions include snakes and white-throated roundrods feeding on firefly larvae to obtain defensive toxins and certain antbirds employing live crickets during courtship displays. The study also details mutualistic relationships, such as sloths relying on moths that contribute nitrogen through their life cycle in the sloths’ fur, which in turn supports algae growth consumed by the mammals. Sloths exhibit a cyclical behavior by descending from trees monthly to defecate, creating habitat for moth eggs.
The paper raises concerns about the future of these intricate interdependencies amid widespread habitat changes. Although insect population declines differ across regions and ecosystems, the study warns that significant disruptions to insect communities are inevitable as land use intensifies. Such changes could have far-reaching consequences for vertebrates that depend on insects in varied ways.
Grames described the findings as a “wake-up call” highlighting the necessity of prioritizing insect conservation. She noted that preserving insects benefits the broader ecosystem, as insects support habitat creation, disease regulation, waste removal, and other vital services. Furthermore, insects play a key role in global carbon cycles by breaking down leaf litter and dead wood—activities that influence about 12% of global forest carbon stocks—and they assist with forest regeneration through seed dispersal and pollination, especially where larger seed dispersers have declined.
The study also underscores current gaps in understanding these relationships, pointing to a lack of systematic research on both trophic and non-trophic insect-vertebrate interactions. Co-author Chris Elphick, professor of ecology and evolutionary biology at the University of Connecticut, stressed that effective conservation efforts require acknowledging the broad ecological roles of 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.