Male-based key to genera for the subfamily Formicinae (Hymenoptera: Formicidae) for the Nearctic region

Authors: RASOAMANANA, NICOLE - Mississippi State University; MACGOWN, JOE - Mississippi State University; FISHER, BRIAN - California Academy Of Sciences; HILL, J. - Mississippi State University

Submitted to: ZooKeys
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2026
Publication Date: 5/20/2026
Citation: Rasoamanana, N., Macgown, J., Fisher, B.L., Hill, J.G. 2026. Male-based key to genera for the subfamily Formicinae (Hymenoptera: Formicidae) for the Nearctic region. ZooKeys. 1280: 1-43. https://doi.org/10.3897/zookeys.1280.176598.
DOI: https://doi.org/10.3897/zookeys.1280.176598

Interpretive Summary: Male ants remain one of the least documented sources of morphological information in ant taxonomy, despite their frequent presence in biodiversity surveys. Within the ant subfamily Formicinae, identification tools for males are especially limited in the Nearctic region, with Smith’s (1943) key being the only comprehensive resource and now outdated.This study presents a revised, illustrated key to the 14 Nearctic formicine genera based solely on male morphology, supported by updated diagnoses and diagnostic figures, including genitalia and wing venation. The key enables reliable identification of male ants, including those collected independently of workers in light traps and other passive-capture methods, thereby improving the integration of male specimens into taxonomic and biodiversity research. This work supports the U.S. Department of Agriculture, Memorandum 1078-020, #3: Protecting the Integrity of American Agriculture from Invasive Species. Accurate identification of both invasive and native ants underpins ecological monitoring programs and the development of non-chemical, sustainable strategies for invasive ant management. By strengthening the ability to distinguish harmful species from beneficial native ants, this research contributes to practical approaches that protect livestock, reduce agricultural losses, and support long-term agricultural resilience.

Technical Abstract: Male ants remain one of the least documented sources of morphological information in ant taxonomy, despite their frequent occurrence in biodiversity surveys and their potential value for systematic research. Within the ant subfamily Formicinae, identification resources for male ants are particularly limited in the Nearctic region. The only comprehensive treatment remains Smith’s (1943) key to male ants of the United States, which predates modern taxonomic revisions and advances in morphological terminology. Here we present a revised identification key to the genera of Nearctic Formicinae based exclusively on male morphology. An illustrated key to the 14 formicine genera recorded from the Nearctic region is provided, supported by updated diagnoses and figures of diagnostic characters, including genitalia and wing venation. This study provides the first modern synthesis of male morphological characters for Nearctic Formicinae and enables reliable identification of males, including specimens collected independently of workers in light traps, Malaise traps, and flight-intercept traps, thereby facilitating the broader integration of male morphology into taxonomic and biodiversity research on ants.