Ant Queens Consume Infected Offspring to Prevent Disease Spread

In a remarkable display of survival strategy, queen ants of the species Lasius niger (black garden ants) have been observed engaging in filial cannibalism—consuming their own infected larvae—to protect their colonies from potential disease outbreaks. This behavior not only curbs the spread of infections but also recycles valuable nutrients, enhancing the queen's reproductive success.

Behavioral Observations

Researchers have documented that when a queen ant detects fungal infections, particularly from pathogens like Metarhizium, in her brood, she promptly consumes the affected larvae. This preemptive action ensures that the infection does not escalate to a contagious stage, thereby safeguarding the health of the entire colony. Notably, queens were found to cannibalize 92% of the infected larvae presented to them, while only 6% of healthy larvae were consumed.

Reproductive Benefits

The act of consuming infected offspring appears to confer significant reproductive advantages. Queens that practiced this form of cannibalism exhibited a 55% increase in egg production compared to those that did not. This suggests that the nutrients obtained from the infected larvae are repurposed to fuel further reproduction, thereby enhancing the queen's fitness and the colony's growth potential.

Protective Mechanisms

A critical aspect of this behavior is the queen's ability to consume infected larvae without succumbing to the pathogens herself. Studies indicate that queen ants produce an acidic, antimicrobial venom from a specialized gland located at the end of their abdomen. This venom is believed to neutralize the pathogens present in the larvae, allowing the queen to safely ingest the infected brood without adverse effects.

Adaptive Significance

This form of "hygienic cannibalism" serves a dual purpose: it mitigates the risk of disease spreading within the colony and recycles nutrients to bolster the queen's reproductive output. By eliminating potential sources of infection and repurposing their biomass, queen ants enhance both their own fitness and the overall resilience of the colony. This behavior underscores the complex and adaptive strategies evolved by social insects to maintain colony health and ensure survival.

Sources:

https://phys.org/news/2024-09-ant-queens-cannibalize-sick-offspring.html?utm_source=chatgpt.com

pubmed.ncbi.nlm.nih.gov

Filial cannibalism, where parents eat their own offspring, is a taxonomically widespread behaviour with a multitude of potential adaptive explanations¹. Of these, the impact of pathogens on the expression of filial cannibalism is, in particular, poorly understood. Cannibalising young with …

news.mongabay.com

Ant queens practice a grim but effective form of childcare, eating their own sick larvae to recycle them into new, healthier eggs. A new study shows that by consuming their infected offspring, the queens protect the rest of their colonies from deadly infections while boosting their egg production with the influx of nutrients. Researchers behind […]