Habitat-specific relationships between colony turnover and seasonal dynamics of Solenopsis invictaOA

【Aim】To clarify habitat-specific population dynamics of the red imported fire ant(Solenopsis invicta)and the factors driving these dynamics behind.【Method】We selected four habitat types—peach plantation,pomelo plantation,reservoir bank,and riverbank—in southern China and systematically monitored changes in nest volume,worker density,and colony turnover.【Result】Pronounced habitat-dependent differences existed in seasonal dynamics and colony turnover patterns.In the peach plantation,worker density reached high levels in spring(446 workers·bait^(-1))and autumn(470 workers·bait^(-1)),and nest volume peaked in autumn(15206 cm^(3)),which was accompanied by an increase in the density of new nests(0.016 nests·m^(-2)).S.invicta in the pomelo plantation exhibited an autumn-winter growth pattern,with worker density increasing from 127(workers·bait^(-1))in summer to 231(workers·bait^(-1))in autumn,nest volume reaching 6316 cm^(3) in winter,and the density of new nests peaking throughout the year(0.024 nests·m^(-2)).In contrast,the reservoir bank showed consistently low worker density(123 workers·bait^(-1) in spring and 106 workers·bait^(-1) in autumn)and a stable number of new nests.In the riverbank,nest volume declined continuously across seasons(from 10322 cm^(3) in spring to 6448 cm^(3) in winter),and the density of new nests was significantly lower in autumn and winter.Correlation analyses combined with structural equation modeling demonstrated that population responses of S.invicta to climatic factors were strongly habitat-specific.【Conclusion】This study highlights differentiated seasonal dynamics of S.invicta across habitats and provides insights into the occurrence patterns of this ant in different regions.