Colony genetic structure and queen mating frequency in fire ants of the subgenus Solenopsis (Hymenoptera: Formicidae)

Colony genetic structure was studied in natural populations of three fire ant taxa, Solenopsis richteri Forel, S. geminata (Fabr.), and hybrid S. invicta/richteri , using allozyme markers. All colonies studied exhibited arrays of female genotypes predicted under a model of monogyny (single functional queen) and monoandry (single insemination of queens). Males produced in the colonies appear to originate exclusively from the foundress queen, rather than from any virgin females present in the colonies. Thus these social insect colonies represent simple, albeit enormous, family groups. Single insemination and foundress parentage of males appear to be conserved reproductive traits in the subgenus Solenopsis , whereas another major determinant of colony genetic structure, the number of functional queens, is evolutionarily labile in this group.