Broad presence of ferromagnetism in bees and relationship to phylogeny, natural history, and sociality

TL;DR

This study reveals that ferromagnetism, likely related to magnetoreception, is widespread among bees and other insects, with its strength correlating to body size and social behavior, and it predates bees' evolution.

Contribution

It provides the first broad evidence of ferromagnetism across diverse bee species and non-bee insects, highlighting its phylogenetic distribution and association with natural history traits.

Findings

Ferromagnetism is present in 75% of tested bee species.

Magnetic capacity predates bee evolution, found in non-bee insects.

Magnetic signal strength correlates with body size and sociality.

Abstract

Scientists have long been fascinated by magnetoreception, the innate capacity of many animals to sense and use the Earth's magnetic field for navigation. In eusocial insects like honey bees, magnetoreception has been linked to communication and foraging. However, little is known about magnetoreception's phylogenetic patterns and relationship to species traits and natural history. Here, we demonstrate that putative magnetoreception based on ferromagnetic particles is widespread across a diversity of bee species (72 out of 96 species tested), with no phylogenetic signal. We also detected such putative magnetoreception in non-bee outgroups, suggesting this magnetic capacity predates the evolution of the Anthophila. While magnetic signals were found across a diversity of life history traits, the strength of the magnetic signal varied within and between species, and increased with body size and social behavior.