Insect Societies Have A Lot to Teach About Healthy Social Living

Ants Macro on Green Leaves, Naypong Studio – stock.adobe.com

Agriculture is widely considered the start of humanity living in large, closely inhabited settlements as opposed to small nomadic tribes. With any behavioral change, there is a cost-benefit. We are currently experiencing a real-time cost-benefit of living in an agricultural society with the development of the coronavirus pandemic. Social living has increased humanity’s ability to do just about everything including pathogen (bacterium, virus, disease causing microorganism) transmission.

However, humanity is not the only agricultural society successfully living on Earth today. If we look closely—very closely—there are tiny, yet massively populated societies facing the same pathogen transmission challenges.

Some of these societies have developed unique strategies to protect themselves—like a certain species of aphids whose soldiers explode their abdomens to seal and defend their colony from disease threats.

Others employ versions that we see in human communities, like developing a diverse gut microbiome for strong immune systems.

Taking a closer look at social insect models could be the key to unlocking more effective human strategies for pathogen management.

(A) Comparisons of human and insect societies, based on social grouping sizes (Burchill and Moreau, 2016; Sawe, 2018) and history with agriculture (Pringle, 1998; Schultz and Brady, 2008). (B) Overview of the relationship of defensive symbionts with host and pathogens. Specific image credit from the Noun Project (https://thenounproject.com/): Woman by Lluisa Iborra, Locust by OCHA Visual, Termite by Heberti Almeida, Ant by Jacob Eckert, City by sumhi_icon, Beehive by Juraj Sedlák, Barley by Nathan Stang, and Fungi by CombineDesign. All images used and modified under the Creative Commons License, Attribution 3.0.

Ants, termites, and ambrosia beetles all farm to support the food needs of their communities, a trait they share with modern human settlements. All these agricultural communities share a link between the food they grow and the evolutionary development of defensive symbiotic microbes (a symbiont is usually a lesser organism living in, on, or near another to the benefit of both) that act like an invisible shield to protect their hosts from disease.

Rachel Arango, a research entomologist at the Forest Products Laboratory (FPL), and her colleagues from the Department of Bacteriology, University of Wisconsin-Madison are researching how living in large groups can not only spread pathogens but also beneficial microbes that may boost immune responses and pathogen defenses. In their journal article, “Defensive Symbioses in Social Insects Can Inform Human Health and Agriculture,” published in Frontiers of Microbiology, they explain:

“Social insects provide a window to explore disease management on a society-wide scale. Increasingly, defensive symbionts are recognized for their valuable role in mitigating pathogens, in insects as well as humans…Examples from insects provide insight for microbiome-based therapies and agricultural products, as well as help to address basic questions on how beneficial microbes are transmitted, maintained, and perturbed in social animals.”

Although insect communities are less complex than human establishments, insect models can provide a safe proving-ground to understand how pathogens spread throughout dense populations. And because “the evolutionary and ecological dynamics of microbial symbionts” is not well understood, insect models offer a more controlled way to study how beneficial microbes can be used to systematically target certain pathogens.

“Insects did it first,” explained Arango when asked about the most exciting aspect of her research. “So many problems faced by human societies have occurred in insect societies in some manner or another, so why not learn from them?”

Humans and insects not only share similar community living styles, they also successfully employ the use of microbial defensive symbionts to ensure the health of their societies. Defensive symbionts can offer physiological, chemical, and behavioral protections for their hosts. And although the microbiome of humans is more diverse and multifarious, insect model comparisons offer tantalizing clues about how resilient societies transmit beneficial microbes, their impact on population levels, and how they can advance public health practices.

Population size and density directly equate to the amount and diversity of pathogens circulating in a community. As humans live in more densely packed cities, understanding pathogen transmission in safe, experimental models is becoming even more urgent.

Learning from insect communities is an ongoing study with a lot of potential for advancing human health. Arango and the collaborative research team she works on recently submitted a grant that builds on this research through a termite-centered focus. Additionally, she reports that another collaborative team has spent years working with ants to tackle the issue of antibiotic resistance by culturing insect-associated microbes in order to find novel antimicrobials.

The collaborative work of FPL’s research entomologists is helping to move humanity into a safer, healthier future. To find out more about the amazing advancements our scientists are making, visit the Forest Products Laboratory at: https://www.fpl.fs.fed.us/