Prince, D.C. & Yanoviak, S.P.

Multisensory homing in the neotropical understory twig-nesting ant Pseudomyrmex boopis (Hymenoptera: Formicidae)

Organisms integrate information from a variety of cues to sense their surroundings, but the relative importance of specific sensory modalities is context-dependent. Ants inhabiting the tropical rainforest understory should bias investment in sensory systems that match the selective pressures of a physically complex, low-light habitat. We examined the role of visual and olfactory cues in the homing behavior (returning to a nest site) of Pseudomyrmex boopis (Roger, 1863), a diurnal, understory, twig-nesting ant with large compound eyes. We measured homing success (entering the nest) and efficiency (duration of homing) after displacement in a field experiment with three sensory manipulations: occluded compound eyes (CE), occluded ocelli (O), ablated antennae (deantennated; A), and combinations thereof. Ant workers in all CE treatments could not home successfully, while workers in O and A treatments homed as well as controls. The O treatment reduced homing efficiency (i.e., increased the time lag between discovering and entering a nest). Workers without antennae took longer to get home and were less efficient. Compound eyes are essential for avoiding predation – nearly a quarter of workers in CE treatments were killed by heterospecific ants or spiders. The results of this study show that P. boopis, a species occupying a much dimmer environment than its arboreal relatives, has multisensory homing behavior that is primarily driven by input to its large compound eyes. This work contributes to our understanding of the relative importance of sensory cues during multimodal homing in an understudied, natural setting.

Open access, licensed under CC BY 4.0. © 2023 The Author(s).

Behavior, leaf litter, multimodal navigation, tropical forest, vision.