Colony and population genetic structure of the newly invasive white-footed ant (Technomyrmex difficilis) in the United States

Abstract

The invasive white-footed ant Technomyrmex difficilis has emerged as a rising pest in several regions, yet its invasion dynamics remain underexplored. This species outcompetes native ants and causes agricultural losses by tending pest insects, including aphids and mealybugs. This study provides the first integrated analysis of the species’ behavioral, chemical, and genetic variation across Texas and Florida populations. Observations suggest that the recently discovered Texas population of white-footed ants originated from Florida. Microsatellite and mitochondrial DNA analyses revealed low genetic diversity in both populations, with a shared haplotype consistent with the Texas population originating from Florida. STRUCTURE analysis further supported genetic clustering between the two regions. Despite similar within-colony coefficients of relatedness for workers, the populations differed in reproductive strategy: Florida colonies showed signs of inbreeding and high inter-colony aggression, whereas Texas colonies exhibited potential localized outbreeding, low aggression, and more uniform cuticular hydrocarbon profiles. Aggression was positively correlated with chemical divergence but not with genetic differentiation. This study establishes a foundational understanding and highlights the importance of integrating multiple types of data to understand the invasion biology of Technomyrmex difficilis.

Keywords

aggression behavior / breeding structure / CHC / COI / microsatellite / nestmate recognition

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