Chemistry and Functions of Imported Fire Ant Venom

Abstract

In the United States, imported fire ants are often referred to as red imported fire ants, Solenopsis invicta Buren, black imported fire ants, S. richteri Forel, and their hybrid (S. invicta × S. richteri). Due to their aggressive stings and toxic venom, imported fire ants pose a significant threat to public health, agriculture, and ecosystem health. However, venom plays a vital role in the survival of fire ants by serving various crucial functions in defense, foraging, and colony health maintenance. Numerous reviews and book chapters have been published on fire ant venom. Due to its medical importance and the expanding global distribution of these ants, fire ant venom research remains an active and highly productive area, leading to the discovery of new components and functions. This review summarizes the recent advances in our understanding of fire ant venom chemistry and its functions within fire ant colonies.

Keywords: chemical communication; defensive compounds; external disinfectant; internal antibiotics; predatory toxins; venom alkaloids; venom proteins.

Figure 1

The general structures of fire ant venom alkaloids. R: the alkyl or alkenyl side chain on position six of the piperidine, piperidene, or pyridine ring, which can consist of 9, 11, 13, 15, or 17 carbons.

Figure 2

Chromatograms showing the major piperidine alkaloids in the venom of Solenopsis invicta female alates, the queen in a matured colony, the minim workers in the incipient colony, and normal workers in a matured colony, including 1: cis-C₁₁, 2: trans-C₁₁, 3: trans-C_13:1, 4: trans-C₁₃, 5: trans-C_15:1, 6: trans-C₁₅, 7: trans-C_17:1, 8: trans-C₁₇.