Correlation of the Nest Density and the Number of Workers in Bait Traps for Fire Ants (Solenopsis invicta) in Southern China

Abstract

The relationship between Solenopsis invicta nest density and the number of fire ant workers in bait traps and percentages of traps capturing ants were investigated in the waste land of Wuchuan, Guangdong, South China. The results showed that fire ant nest density is positively correlated with the number of workers captured in traps, and could be described by N=60.53LnD +348.0D+421.1. The workers exceeded 200 and 300 in bait traps while the density of fire ant nests was over 0.023 and 0.084 ind./m2, respectively. The percentages of traps capturing ants were also positively correlated with fire ant nest density and fit by Pe=1/(1+e0.9694-309.85D). When the nest density was over 0.018 ind./m2, over 99% of traps captured fire ant workers. N=8.8796e0.0346Pe was the fitting line for worker amount and trap percentage. The workers per trap were about 50, 100, and 200 when the trap percentages were 50%, 70% and 90%, respectively.