Abstract: 【Aim】 After death, worker corpse is vulnerable to pathogen infection, which is harmful to the health of the entire nest of ants. To avoid horizontal transmission of pathogens, live workers recognize corpses by changes in chemical cues from corpses and removed them to refuse piles. This study aims to test the behavioral response of workers of the red imported fire ant, Solenopsis invicta to six fatty acids including oleic acid, linoleic acid, palmitokic acid, palmitic acid, stearic acid and myristic acid, which may play important roles in its necrophoric behavior. 【Methods】 The fatty acid components of body extracts of live and dead ant workers were analyzed with GC-MS. The necrophoric behavioral responses of S. invicta workers to six fatty acids (10 μg/μL), the single component oleic acid or linoleic acid at different concentrations (0.75 and 3 μg/μL) and their mixture at different concentrations (0.01, 0.1, 1 and 10 μg/μL) were tested with filter paper disc method. 【Results】 Only linoleic and oleic acids were detected from the corpses of S. invicta worker. The fire ant workers did not significantly respond to four fatty acids, i.e., palmitokic acid, palmitic acid, stearic acid and myristic acid. Both single linoleic acid and oleic acid could trigger significant necrophoric behavior of fire ant workers, which was dose-dependent. The mixture of linoleic acid and oleic acid at the 10 μg/μL concentration could also trigger significant necrophoric behavior of fire ant workers, while showed no significant effect at other lower concentrations.【Conclusion】 The results suggest that oleic acid and linoleic acid, but not other fatty acids, play important roles in triggering necrophoric behavior of S. invicta workers.

Key words: Solenopsis invicta')">Solenopsis invicta, fatty acids, oleic acid, linoleic acid, necrophoric behavior