The red imported fire ant, Solenopsis invicta Buren, poses a significant threat to public health due to its venomous stings. While the chemistry of fire ants has been well investigated, most studies have focused on ants from mature colonies. The dynamic changes in chemical compositions during colony development have been less explored. In this study, we established S. invicta colonies using newly collected queens from the field and then tracked the chemistry of workers as the colonies developed. Our findings reveal that the chemistry of fire ant workers undergoes significant changes with the development of the colonies. However, the change in chemical diversity was not necessarily in the same direction for all individual glands. For example, components in the venom gland became more diversified with colony development, whereas a number of compounds in the Dufour’s gland only existed at the early stage of colony development. Initially, trans-2-methyl-6-tridecenylpiperidine (trans-C13:1-piperidine) could account for up to 98% of all detected alkaloids; however, its percentage gradually, not stepwise, decreased with colony development due to the increase of other alkaloids. During days 50 to 100, production peaks in trans- and cis-2-methyl-6-undecylpiperidines (trans- and cis-C11-piperidine) were consistently observed. Piperidene and pyridine alkaloids were also detected within two months of colony age; however, piperidine alkaloids were always the first to appear, followed by piperidene and pyridine alkaloids. In addition to Z,E-α-farnesene, Z,E-α-homofarnesene, Z,Z-α-homofarnesene, heptadecane, and nonadecane, six geranyl esters of fatty acids were identified among the 32 new compounds. As expected, the origin of these compounds was the Dufour’s gland. Although these compounds were consistently detected in sting extractions, they seldom appeared in milked venom (2 out of 30 cases). These compounds may be unique to fire ants in the early stages of colony development.

Colony development, Venom alkaloids, Incipient colony, Chemical profiles, Piperidine alkaloids, Piperidene alkaloids, Pyridine alkaloids, Poison gland, Dufour’s gland, Sting apparatus