A bitter receptor links chemical detection to adaptive foraging avoidance in fire ants

Bitter taste perception is critical for insect foraging decisions, yet the molecular basis of bitter-mediated deterrence remains poorly understood in invasive ants such as Solenopsis invicta. Elucidation of gustatory receptor mechanisms may facilitate the development of behaviorally informed strategies to modulate fire ant foraging.

The gustatory receptor SinvGr145 was broadly expressed in forager tissues and enriched in the antennae. Heterologous expression in HEK293T cells showed that the bitter compounds umbelliferone and L-canavanine selectively and dose-dependently activated SinvGr145, with EC₅₀ values of 2.98 and 5.356 mM, respectively. Antennal single sensillum recordings revealed strong, concentration-dependent neuronal responses to both compounds, which were significantly attenuated following RNA interference-mediated knockdown of SinvGr145. Consistently, in situ hybridization localized SinvGr145-expressing neurons to the antennae, and silencing SinvGr145 reduced behavioral avoidance of bitter-laced food sources. Furthermore, the incorporation of bitter compounds into bait substrates decreased forager recruitment and consumption.

This study identifies SinvGr145 as a molecular link between bitter chemical cues and deterrent foraging behavior in S. invicta. Targeting gustatory receptor-mediated bitter perception may provide a foundation for developing receptor-based strategies to regulate fire ant foraging in pest management programs. © 2026 Society of Chemical Industry.