Abstract
Fire ant venom contains insecticidal alkaloids named ‘solenopsins’. Whilst species-specific differences are reported, little attention has been given to caste-specific venom adaptations. The venom of fire ant queens has remained particularly poorly studied, though studies have shown it to be strikingly similar across different species, in being primarily composed of the alkaloid isosolenopsin A, regardless of the chemical configuration in workers. We predict that this is the evolutionary outcome of stabilising selection, implying that a shared mechanism is responsible for the conserved venom composition among fire ant queens. The present investigation tests whether venom plays a role in nest founding, when queens must succeed in isolation in the field against competitor species. Here, we report that fire ant queen venom and isosolenopsin A are faster to incapacitate alien ants than the venom of fire ant workers. Representative sympatric competitor ant species were selected and exposed on their heads to the venom of workers and queens of the invasive fire ant species Solenopsis invicta and S. geminata. Queen venom was found to incapacitate rival foragers quicker than worker venom. The effects were reproduced using synthetic solenopsins, establishing that solenopsin A analogues are particularly effective contact neurotoxins. Overall, the venom of S. invicta is more lethal than of S. geminata, regardless of the incapacitation speed. We believe these are fundamental aspects of the chemical ecology of the invasive ants which remain overlooked, and emphasise the need for further studies into the venom biology of founding queens.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.